ML20084N298
| ML20084N298 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 05/14/1984 |
| From: | Ellis J Citizens Association for Sound Energy |
| To: | NRC OFFICE OF THE SECRETARY (SECY) |
| Shared Package | |
| ML20084N279 | List: |
| References | |
| OL-1, NUDOCS 8405160458 | |
| Download: ML20084N298 (61) | |
Text
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C A S E (CITIZENS ASSN. FOR SOUND ENERGY)
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May 14, 1984 Docketing and Ser/1ce Section Office of the Secretary U. S. Nuclear Regulatory Commission Washington, D. C. 20555
Dear Sir:
Subject:
In the Matter of Application of Texas Utilities Electric Company, et al. for An Operating License for Comanche Peak Steam Electric Station, Units #1 and #2 (CPSES)
Docket Nos. 50-445-1 and 50-446-1 Affidavit of CASE Witness Jack Doyle We are attaching the original signed and notarized Affidavit of CASE Witness Jack Doyle.
Please note that Mr. Doyle has included as part of his Affidavit the
SUMMARY
portion of CASE's 5/14/84 ANSWER TO APPLICANTS' MOTION FOR
SUMMARY
DISPOSITION OF CERTAIN ALLEGATIONS REGARDING AWS AND ASME CODE PROVISIONS RELATED TO WELDING ISSUES, and the entire CASE'S ANSWER TO APPLICANTS' STATEMENT OF MATERIAL FACTS AS TO WHICH THERE IS NO GENUINE ISSUE, We are also attaching copies of these documents.
Please also note that, as indicated in the attached letter dated 5/14/84 to the Licensing Board and parties in the hearings, Mr. Doyle telephoned me-after our pleadings had already been typed, printed, and collated, and stated that he wished to add one additional reference which was inadvertently omitted. Page 9 of CASE'S 5/14/84 ANSWER TO APPLICANTS' MOTION FOR
SUMMARY
DISPOSITION etc. has been revised and is attached to our 5/14/84 letter. We are also attaching a copy of our letter and the revised page 9.
Sincerely, CASE (Citizens Association for Sound Energy)
Mrs.) Juanita Ellis President cc Service List 8405160458 840514 I PDR ADOCK 05000445 0 PDR ,
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.' CASE EXHIBIT 716
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i 1 TEXAS UTILITIES : !
REv. Issu,,E
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- AGE SERvlCES INC.
ENGNEERWG Gu!OELNE TITLE COVER SHEET 4 f//-p5 17 i FOR UFnovac. ----
GUIDELINE sacTIoN II d hNr-
- REVIS!ONS WELD CALCUIATIONS '
l' PSE PROJ. ENGR. #
I i I. INSTRUCTIONS FO, R FILING GulDELINE PAGES
! 1. Replace the existing sheets 1 thru 7 with the enclosed sheets 1 thru 17.
- 2. Replace the existing cover sheet, Rev. 3 with this cover sheet, Rev. 4. .
1
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1 II. STATUS OF GUIDELINE PAGES I
PAGE REV PAGE REV PAGE REVlPAGE REV PAGE REV PAGE REV 1 5 10 0 l 2 -
4 11 o 8
I 36 0+ 12 0 i
4 4 13 0 '
5 4 14 o\
6j* 94 15 0
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SECTION XI: WELD CALCULATIONS .
1.0 GENERAL This section supplements weld stze requirements as addressed in reference "C". ,
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2.0 REFERENCES
A. Design of Welded Structures. Blodgett B. AISC Handbook (7th Edition)
C. ASME Section III Division 11974 Edition with Winter 1974 Addendum.
D. American Welding Society Code D1.1
(
3.0 PROPERTIES OF WELDS For analysis of a weld, the weld will be considered as a line.
Some general configurations tased upon this assumption with their corresponding properties are indicated in figure 1.
3.1 Weld Size Selection The calculated weld size is found by determining the actual re-sultant force on the weld and comparing it to the allowable force for that weld size.
The largest loads are to be used when determining the required weld size.
The allowable stress for linear component support welds shall be in accordance with Table NF-3292.1-1.
The minimum weld based upon structural member thickness is as inidcated in figure 2. ,
3.2 Skewed Joints
( Fillet welds may be used gt skewed joints where the angle is equal or greater than 60 but less than or equal to 1359.
(Figure 3) l . .
l
e Rev. 4 SECTION XI i l
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If a member is to be joined at an angle greater than 30 0 or less than 600, a bevel groove weld is to be used. (See Figure 3). The effective throat is indicated in parentheses. '
l If a member is to be attached at an angle greater than 135 0 , the l
l member should be machined to yteld an angle less that 1350,but '
i greater than 600 . (SeeFigure3.)
l .
3.3 Welding of Structural Tubes . <
t '
. When two tubes of equal size are welded together, a flare bevel weld should be specified. The effective throat is as shown in j . Figure 4.
i l l When two tubes of unequal size are welded together, a fillet l
- weld shall be specified in all cases. The effective throat l is indicated in Figure 5. l j For combined fillet and flare bevel welds the effective throat l
1s as indicated in Figure 6. !
3.4 Weld Swbols
! Subsection NF weld inspection procedure paragraphs must be specified
(, in the tail of the weld symbol using the fol' owing codes:
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- . 52 '
l "A" "B" -
l ASME CLASS "A" NF- 5232
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'5UPPORT TYPE "B"
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Plate & Shell 1 1 ,
1 2 & MC 2 - - ---
Linear 2 j 3 3 '* :. 5,'ComponentStd.
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! No NF weld symbols are required for class 5 supports or for welds to th's pipe. -
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- only welds that connect two plate and shall elements shall be desig-nated as plate and shell. -
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Rev. 4 SECTION XI .
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FIGURE 3 3
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,s '. SECTION XI Rev. 6 ,
Figure 4 .
Two Structural Tubes of Eq'ual Size. .
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Effective . throat "te" for k
- design te=
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0" E 625t2 1 Q ..
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- Figure 5 Two Structural Tubes of Unequal Size
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1/8 max.
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45" min.45 min. ,
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(t min.)
t X t) 7 4 r s](min.
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Shown on dwi. ( <
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Effective Throat = 0.707 W '
t = Thickness of thinner material i To be used only when the ratio Effective Throat = c ,
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Tobeusedwhentheratiooff>.
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(,s Effective Throat = t. Show the he leg dim. on the hgr. Nwg.
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i l CASE EXHIBIT 886 r1 l
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Public Library i.
Sixth Edition MAY .101979 i Dallas Public Library .
SECTION FOUR Metals ,
And Their Weldability Edited by len Griffing Published in 1972 by AMERICAN WELDING SOCIETY 2501 N.W. 7th Street Miami, Florida 33125 l
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'a Quenched and Tempered Heat-Treated Low-Alloy Stects / 63.25 w-w-
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- a u Fig. 63.8.-Efect of weld preheat at 47.000 joules per in. on Charpy Y notch curves for sumulated grain-coarsened heat-afected tone in %-in. thickness of typical A514!317 steel Welding Technique The stringer-bead technique, in which weld beads are depe :d without appreciable transverse oscillation of the electrode, is preferred , r welding quenched and tempered steels. A weave bead, with its slower tr vel speed,
, the heat permits the arc to linger over each portion of the joint and increr input. Furthermore, stringer bead technique reduces distortion and tavors good weld-metal toughn:ss.
Where arc Fouging is used, such as removing base metal or previously de-posited weld metal at the root of the joint, grinding is usually necessary to clean the surfaces prior to welding. Dunng gouging, the are should be moved as rapidly as possible, consistent with good gouging practice, to avoid excessive heat input. Gouging with an oxygen-cutting torch should not be done on these steels because of the danger of overheating quenched and tempered steel.
Postweld IIcat Treatment Experience with structures and pre;sure vessels in service, and information from full-scale tests, show that thermal
- tress relief is not required to prevent brittle fracture in welded quenched and tempered steels of the types discussed here. In fact, notch toughness tests have demonstrated that exposure to tem-peratures in the range of 950 to 1200*F (510 to 694*C) may actually impair the toughness of both the weld metal and heat affected zone, and that the extent of this impairment is greater with the slow cooling rate that is necessary for stress relief. Also of concern when weldments are given such a heat treat.
ment is that intergranular cracking may occur in the grain coarsened region of the heat-aficcted zone. When it does occur, this type of cracking occurs during the early stages of the heat treatment before the high residual stresses from welding have been significantly reduced. The mechanism is one of stress rupture. This type of cracking has been prevented from occurnng at the toes of fillet welds by properly contouring the welds to minimize stress concentra-tions, by peening at the toes of the welds, or by depositing weld metal whose elevated temperature strength is significantly lower than that of the base metal heat affected zone.
Stress relief may be required for weldments that must retain dimensional stability during machining, or where stress corrosion may be involved, although neither of these requirements is unique to quenched and tempered steels. The
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CASE EXHIBIT 908 - ANSI /AWS D1.1-82
. ANS!!AWS D1.182 An American National Standard Approved by American National Standards Instituto January 25,1982 Structural Welding Code-Steel Sixth Edition Superseding AWS DI.l.81 Prepared by
. AWS Structural Welding Committee L'nder t'..e Direction of AWS Technical Activities Committee Approved by AWS Iloard of Directors EffectiscJanuary I 1932 i .
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550 North Lejeune Rd., Miami, FL 33126
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Details ofit'eldedJointsI$
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i i Table 2.3.1.4 Effectivo throats of flare groove welds W 9' 2 I d
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i Flate besel. FlateV- '
b b groose melds groove melds ,
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[ \ ransverse All diam bars 2 Mt T
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$ 16 R tr2 R* "-
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te wied e'ong
.-A . these ends
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Noie:R = radiusof bar.
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'Escept 3 8 R for GNtAW lescert short circuiting transfer) -* += Actual process w ith bar sites 1 in. I211 mm) diam and oscr.
Note: The offactive area of weld 2 shaf t equal that of weid 1 but its s.n shaf t t,e its of fective sin plus the thickness of the f.uer T.
Fig. 2.4.2-Fillers less than 1/4 in, thick 7,
Details of WcldedJoints t
2.6 Joint Qualification V fF'8 - - - - - - - -
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2.6.1.foints meeting the following requirements are des.
b b
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ignated as prequalified. 3 7
)i y (1) Conformance with the details specified in 2]
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through 2.10 and 10.13.
Tranmise ,
(2) Use of one of the following wc! ding processes in 3 ,
accordanes w ith the requirements of Sections 3. 4. and 8.
- 9. or 10 as applicable: shielded metal are, submerged are*
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along these i r r i gas metal arc (escept short circuiting transfer), or Dus enos g -
__ . .q cored arc 'selding. , ,
2.6.l.1 Joints meeting these requirements may be used without performing the joint weldmg procedure qualifb cation tests prescribed in 5.2.
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2.6.l.2 The joint welding procedure for all joints
- 1. The ef fective area of wetd 2 shati eawat that of weid 1. The welded by short circuiting transfer gas metal are weldmg lenam of weid 2 mati be sutfic.ent is avo.d overitresing tae Isee Appendis D) thall be qualined by tests prescribed in finer m out atong piane n a.
3 ,- 2. The efrui ve ern of weid 3 eau et ient equal thu of weio i and there insis be no cn,eritreis of the ends of weid 3 reiuti.n 2.6.2 Joint details may depart from the details prescribed "***"""'""*'""**"""*'h""'
in 2.9 and 2.10 anJ in 10.13 only if the contractor submits I to the lingineer his proposed joints and joint welding Fig. 2.4.3--Fillers 1/4111. or titicker procedures and at his own espense demonstrates their adequacy in accordance with the requirements of 5.2 of this Code and their conformance with applicable prosi. 2.7.1.1 The minimum Gilet weld slie, except for Ollci tions of Sections 3 and 4, welds used to reinforce groose welds, shall be as show n in Table 23.
. 2.7.1.2 The masimum fillet weld slie permitted along 2.7 Details of Fillet Welds edges ofinsteriai shaiibe
- (l) the thickness of the base metal, for metalless than 23.1 The details of Gilet welds made by shle!ded metal 1/4 in. (6.4 mm)thkk (see Fig. 23.1. detail A).
i2) til6 in. (1.6 mm)less than the thickness of base 4 arc. submerged arc. gas metal are (except short circuiting transferl, or dus cored arc welding to be used without joint weldmg procedure quahrications are listed in 23.1.1 metal, for metal 1/4 in. (6 4 min) or more in thickness (see l'ig. 23.1. detail II). unless the weld is designated on through 23.l.$ and detailed in l'igs. 2.7.1 and 10.13.$, the drawing to be built out to obtam full throat thickness.
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Derails of WeldedJoints17
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U transfer), or flus cored are welding processes are listed in thickness of the part containing it, escept those ends '
2.8.2 through 2.8.8 and 3.3.1 and may be used without which extend to the edge of the part.
performing the joint welding procedure qualification pre- 2.3.7 The minimum spacing of lines of s!ot utids in a scribed in 5.2, provided the technique provisions di 4.21 direction transserse to their length shall be four times the or 4.--, as applicab!e, are complied with, width of the slot. The minimum center to-center spacing 2.8.2 The minimum diameter of the hole for a plug weld in a longitudinal direction on any line shall be two times shall be no less than the thickness of the part containing it the length of the slot.
plus 5/16 in. (8.0 mm), preferably rounded to the nest 2.8.8 The depth of filling of plug or slot welds in metal greater odd I/16 in. (l.6 mm). The maximum diameter of 5/8 in. (15.9 mm) thick or ! css shall be equal to the thick-the hole for a plug veld shall not be greater than 2 l/4 ness of the material. In metal oser $13 in. thick, it shall times the depth of filling. be at least one. half the thickness of the material but no 2.8.3 The minimum center.to center spacing of plug less than 5/8 in.
wc!ds shall be four times the diameter of the hole.
2.8.4 The length of the slot for a slot weld shall not exceed ten times the thickness of the part containing it. The width Sy mbols forjoint types of the slot shall be no less than the thickness of the part D-butt joint containing it plus 5/16 in. (8.0 mm). preferably rounded C-cornerjoint to the next greater odd I/16 in. (1.6 mm), not shall it be T-T. joint DC-butt or comerjo:nt greater than 21/4 times the depth of filling. TC-T orcornerjoint 2.8.5 Plug and slot welds are not permitted in quenched DTC-butt. T.. or cornerjoint and tempered stects.
S)mbols for base metal thickness and penetration L-limited thickness-complete jomt penetration U-unlimited thickness-complete joint penetration Tablo 2.7
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Minimum fillet wold sizo for prequalified joints
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Dase mrtal thickness of Minirnum si e Symbols for weld 13 pes I-square. groove thicker part jointed (T) of fillet wcid' 2-single.V.groose 3-double.V.groose in. mm in. mm 4-sing!c-bevel.groose Tul/4 TC 6.4 1/8" 3 5-double. bevel. groove 1/4 <Tcl/2 6.4<T<12.7 3/16 5 Single. pass 6-single.U. groove I/2<T43/4 12.7 <TC 19.0 1/4 6 welds must 7-double.U. groove 3/4<T 19.0 < T 5/16 8. be used 8-single.J.groos e
'Eteept that the we!J size need not eseced the thi;kness of the thinner part joineJ. For this esception, particular care S)mbols for welding processes if not shleided metal are should be taken to provide sufficient preheat to ensure weld S-submerged are welding soundness. 0-gas metal are welding
" Minimum size for bridge applications is 3/16 in. F-flus cored are wtidmg The lower case letters, c g., a, b. c. etc., are used to differentiate 2.8.6 The ends of the slot shall be semicircular or shall betann joints that wou!J otherwise have the same joint d:signation.
have the comers rounded to a radius not less than the 4
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Is'o rkmanshipl41 V or 5% of the thickness, whichever is smaller nor leave particle inspection dye penetrant inspection, or other reinforcement that exceeds 1/32 in. Ilowever. all rein- equally positive means: remove the crack and sound metal forcement must be removed where the weld forms part of 2 in. (50 8 mm) beyond each end of the crack, and reweld.
a faying orcontact surface. Any reinforcement must blend smoothly into the plate surfaces with transition areas free 323 Members distorted by wc! ding shall be straightened from edge weld undercut. Chippmg may be used provided by mechanical means or by carefully supervised applica-it is followed by grmding. Where surface finishing is t on of a limited amount of localized heat. He tempera-required. its roughness value shall not exceed 250 in ture of heated areas as measured by approved methods (6.3 m). Surfaces finished to values of over 125 in. (3..;. shall not exceed 1100* F (590* C) for quenched and tem-m) through 250 in. shall be finished parallel to the pered steel nor 1200' F (650' C) (a dull red color) for direetton of primary stress. Surfaces finished to values of other stects. De part to be heated for straightening shall 125 m. or less may be finished m any direction. be substantially free of stress and from external forces.
3.6.3.1 Ends of butt joints required to be flush shall be except those stresses resulting from the mechanical finished so as not to reduce the width beyond the detailed straightening method used in conjunction with the appli-width or the actual width furnished, whichever is greater, cation of heat.
by more than 1/8 in. (3.2 mm) or so as not to leave 324 Prior approval of the Engineer shall be obtained for reinforcement at each end that exceeds 1/8 in. (3.2 mm). repairs to base metal (other than those required by 3.2).
Ends of wc!ds in butt joints shall be faired to adjacent repair of major or delayed cracks, repairs to electroslag plate or shape edges at a slope not to exceed I in 10. and electrogas welds with intema! defects. or for a revised 3.6.4 Welds shall be free from overlap. design to compensate for deficiencies.
325 The Engineer shall be notifled before improperly fitted and welded members are cut apart.
3.7 Repairs 326 Ir. after an unacceptable weld has been made, work is performed which has rendered that weld inaccessible or 321 The removal of weld metal or portions of the base has created new conditions that make correction of the f metal may be done by machining, grinding, chipping. unacceptable weld dangerous orineffectual. then the orig-5g osygen gouging, or air carbon are gouging. It shall be inal conditions shall be restored by removing welds or done in such a manner that the remaining weld metal or members or both before the corrections are made. If this base metal is not nicked or undercut. Oxygen gouging is not done, the deficiency shall be compensated for by shall not be used in quenched and tempered steel. Unsc- additional work performed according to an approved re-ceptable portions of the weld sha!! be remosed without vised design.
substantial removal of the base metal. Additional weld metal to compensate for any deficiency in size shall be 3.7.7 Restoration of Unacceptable llotes by Welding.
deposited using an electrode preferably smaller than that When base metal with punched or drilled mistocated used for making the original weld, and preferably not holes is to be restored to its ongmal condition by welding, more than 5/32 in. (4.0 mm) in diameter. The surfaces the following requirements shall apply:
shall be cleaned thoroughly before wc! ding. (1) Restoration by weldmg is not recommended unless required for structural reasons.
322 De contractor has the option of either repairing an (2) Holes in material not subject to tensile stress may unacceptable weld or removing and replacing the entire be restored by welding, provided that wc!d soundness is weld, except as modified by 3.7.4. The repaired or re- verified by either radiographic or ultrasonic inspection to placed weld shall be retested by the method originally the acceptance criteria for compressive stresses.
used, and the same technique and quality acceptance (3) Restoration of holes by welding in material subject criteria shall be applied. If the contractor elects to repair to tensile stress is prohibited, except when approved by the w eld, it shall be corrected as follows:
the Engineer and the weld soundness is verified by cither 3.7.2.1 Overlap or Excessive Convexity. Remove ex- radiographic or ultrasonic inspection to the acceptance cess weld metal. criteria for tensile stresses.
322.2 Excesstie Concavity of Weld or Crater, Un* (4) Prior to restoration of mistocated holes in a produc.
dersize Welds. Undercutting. Prepare surfaces (see 3.11) tion member, a welding procedure specification shall be and deposit additional weld metal. -
prepared setting forth the welding procedure, technique.
3.7.2.3 Excessive Weld Porosity, Excesslie Slag inclu- materials, and representative joint geometries to be used slons, Incomplete Fusion. Remove unacceptable por-
- for the restoration. Sample welds shsil be made following
( tions (see 3.7.1) and reweld. the wc! ding procedures specification. The sample weld in 322.4 Cracks in Weld or Base Stetal. Ascertain the any material shall meet the soundness criteria of (2) or (3)
{ extent of the crack by use of acid etching, magnetic above as applicable. For restoration of mistocated holes in quenched and tempered steel, sufficient additional samples shall be prepared to perform the following me.
- 7. ANSI B46.l. Surface Testure. in mictoinches e in.). chanical tests:
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9 42/ Wo1LEM ANSHIP No. of tests Apeof test requirement shall apply not only to successive layers but i .
Reduced section tens. ion also to successive beads and to the crater area when test welding is resumed after any interruption. It shall not, e, however restrict the welding of plug and slot we!ds in 2 Side-bend tests accordance with 4.21 and 4.22.
3 1.ongitudinal Charpy v. 3.11.2 Cleaning of Comp!cted Welds. Slag shall be re.
I notch tests. (The Charpy V. moved from all con;pleted wc!ds and the wc!d and adja.
notch to be located in the cent base metal shall be cicaned by brushing or other heat.affected zone and not. suitable means. Tightly adherent spatter remaining after
' mal to the section or plate the cleaning operation is acceptable unless its removal is surface. required for the purpose of nondestructive testing. Welded joints shall not be painted until after welding has been (5) The welding procedure specification and all test completed and the weld accepted.
results shall be approved by the Engineer prict to restora.
tion welding on a production member. Production w c! ding shall be done in accordance with the established weldin:
procedure specification and within the limitation of van. 3.12 Weld Termination ables set forth in 5.5 of this Code. The Engineer should-accept documented evidence of previously satisfactorily 3.12.1 Welds shall be terminated at the end of a joint in a tested sample wc!ds. manner that will ensure sound welds. Whenever neces.
(6) Weld surfaces shall be finished as specified in 3.6.3. sary, this shall be done by use of extension bars and runoff plates.
3.12.2 In building construction extension bars or runoff 3.8 Peenin"a PI 'es need n t be removed un! css required by the Enginect.
3.8.1 Peening may be used on intermediate weld layers for 3.12.3 In bridge constmetion. extension bars and runoff control of shrinkage stresses in thick welds to prevent Pl ates shall be removed upon completion and cooling of (
cracking. No peening shall be done on the root or surface the wc!d. and the ends of the weld shall be made smooth layer of the weld or the base metal at the edges of the weld and flush with the edges of abutting parts.
except as provided in 10.7.5(3). Care should be taken to prevent overlapping or cracking of the weld or base metal.
3.S.2 The use of manual slag hammers. chisels, and light. 3.13 Groove Weld Backing weight vibrating tools for the removal of slag and spatter is permitted and is not considered peening. 3.13.1 Groove welds made with the use of steel backing shall have the weld metal thoroughly fused with the backing.
3.9 Caulking 3.13.2 Steel backing shall be made continuous for the full length of the weld. All necessaryjoints in the steel back.
Caulking of welds shall not be permitted. ing shah be completejoint penetration welds in butt joints meeting all the workmanship requirements of Section 3 of this code.
3.10 ArcStrikes 3.13.3 firidge Structures. on bridge structures, steel backing of welds that are transverse to the direction of Arc strikes outside the area of permanent welds should be C mPuted stress shall be remosed and the joints shall be amided on any base metal. Cracks or blemishes caused gr und or finished smooth. Steel backing of welds that by are strikes shall be ground to a smooth contour and are parallel to the direction of stress or are not subject to checked to ensure soundness. c mputed stress need not be removed, unless so specified 1 by the Engineer.
Where the steel backing of longitudinal welds in bridge structures is etternally attached to the base metal by 3.11 Weld Cleaning "e ding such welding sha!! be continuous for the length of the backing.
3.II.I,In. process Cleaning. Defore welding o er previ.
ously deposited metal, all slag shall be remmed and the 3.13.4 Iluildings and Tubular Structures. Steel backing of welds used 6n bu Idmps or tubular structures need not weld and adj.went base metal shall be brushed clean. This be remmed. unless required by the Engmeer.
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194 / APPENDIX B '
Table B q Equivalent fillet weld leg size factors for skewed T joints A Dihedral angle. $ 60 65 70 75 80 85 40 95 k l k Comparable fillet w c!d size for same strength 0.71 0.76 0.81 0.86 j j 0.9 ) 0.46 1.00 1.03 ll(
Dihedralangle 6 100 !!$
105 110 120 125 130 135 ;k, Comparable fillet u eld Il size for same strength 1.08 1.12 1.16 1.19 1.23 1.25 1.28 I.31 1 i; .
J ,
For fillet welds having equal measured legs (w ), the For gaps < !/16 in.. use 4 distance from the root of the joint to the face of the dia- gn = 0 and t'. = t.
grammatic weld (t.) may be calculated as follows:
{y3;
- y For gaps > 1/16 in. and 43/16 in.. use g,wn - g,,
where the measured leg of such fillet wcid (w ) is the perpendicular distance from the surface of the joint to the ip i i g opposite toe, and (g) is the gap, if any, between parts. I 2 sin , See Fig. 2.7.1. Acceptable gaps are defined in 3.3.1. l ,g
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- CASE EXlilBIT 909 -
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Commentary on Structural Welding Code i
-Steel i I
Third Edition Prepared by AWS Structural Weld;ng Committee
) Under the Direction of AWS Technical Actisitics Committee Apprmed by AWS Daard of Directors i
247
9Y ~. .
Foreword This commentary on AWS DI.181, Structural We!J. tended to provide a detailed resume of the studies and ing Code-Steel, has been prepared to generate better research data rolewed by the Committee in formulating understanding in the application of the Code to we!Jang the provisions of the Code, in steel construction. Generally, the Code does r.ot treat such design consid.
Since the Code is written in the form of a specification, erations as loading and the computation of stresses for the it cannot present background material or discuss the Com. purposes of proportioning the load carrying members of mittee's intenti it is the function of this commentary to the structure and their connections. Such considerations Oli this need. are assumed to be coscred cliewhere, in a gener:.1 builJ.
Suggestions for application as ueli as clarification of ingcode,bridgespecincation,orsimilardocument. As an Code requirements are offered with specific emphasis on neeption, the Code does provide allowable strenes in new or resised sections that may be len familiar to the user. welds, faugue prosliions for wcids in bridges and tubular 8 - Since the publication of the Grst edition of the Code, the nature of inquiries directed to the American Welding snetures, and strength limitations for tubular connections.
Dese provisions are related to particular propetues of Society and the Structural Welding Committee has indi. welded connections.
cated that there are some requirements in the Code that De Committee has endeavored to prWuce a useful are either difficult to understand or not sufficiently speci. document suitable in language, ferm, and coserage for Oc. and others that appear to be overly conservative, welding in steel comtruction.De Code prosides a means it should be recogniecd that the fundamental premise for establishing welding standards for use in design and of the Code is to provide general stipulations applicable construction by the owner er his designated represents.
to ney situation and to leave sufGeient latitud for the the.De Code incorporates provisions for regulation of cxercise of engineering judgment. welding that are considered necessary for pubhc safety.
Another point to be recognieed is that the Code repre. The Committee recommends that the ownct or ow ner's sents the collective experience of the Committee and while representative be guided by this commentary in appli.
some Provisions may seem overly conservative, they cation of the Code to his wcided structure.%e commen.
has e been based on sound engineering practice, tary is not intended to supplement Code requirements.
The Committee, therefore, believes that a commentary but only to provide a useful document for interpretation is the most suitable means to provide clarification as well and application of the Codet none of its prositions are as proper interpretation of many of the Code requirements. binding.
Obviously, the slee of the commentary had toimpose some Comments or inquirles pertalning to this commentary or limitations with respect to the satent of coverage, to the Code are welcome. They should be addreued to:
Dis commentary is not intended to provide a hhtorical Secretary. Structural Welding Committee. American Weld.
background of the development of the Code, not is it in. Ing Society.
249 s 1
T Preface It is the intention of the Structural Welding Committee Changes in the commentary from the Grst edition have to revise the cornmentary en an annual basis so that bern indicated by s single vertical line thst appearn in ths commentary on the changes to the Code ca.1 be promptly margin immediuely adiacent to the paragraph affected.
supplied to the 'act. In this manner, the commentary Changes to tables and Ogures, as well as new tables or will always be current with the edition of the Structural new Ogures, hase not iseen so lndicated.
Welding Code-Steel w 6th w hkh it h hound.
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= = = = - ame .1= . ..s. . u . . . . . . ,
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I B7 Commentary on .
Structural Welding Code-Steel
- 1. General Provisions Note:Allreferences to nurnberedparagraphs, tables, andfigures, unicss otherwise Indicated, refer to paragraphs, tab!cs, orfigures in A \\'S !)!J, Structura! \\'ciding Code-Sicel. References to paragraphs. tables. or figures In this corntncntary are prefixed with a C. llence, Fig. S.S.S is in A\\'S f)lJ, while Fig. C3.8.5 is in this comtnentary.
I.I A p pllC all0!! nhhed in the as roHed condition. The !.ngineer should recognate that surface imperfections beams, seatw ete.)
The Struetural Weldin; Code. hereinafter referred to as acceptable under A6 and A20 may be present on the ma.
the Code, prmlJes w elding requirements for the construe. terial reeched at tl.e fabricating shop. Special surface 4 tion of steel structures. It liintended to be complementary wtih any general cafe or specification for design and ton
- Onnh quahty, when needeJ in as rolled products. shou!J tv specified in the information furnkhed to the bidden.
Structioft of steel StrVerufen.
Thh Code wat treeineally written for use in the con. ],3 M'chj[gg procc%SCS 6truction of buildings, bridges, of tubular structurci. but its pnnhions are gennally appticable to any steel structure. Certain thic!Ad metal are, submerged are, gas, metal
% hen using the Code for other structures. owners, are (escluding the short circuiting mode of metal transfer architests, and engincen thould recognlie that not all of across the are), and flus cercJ are welding procedures 6n ett proshioni may be applicable or suitable to their conjunction w ith certam related t) pes of joints hase been particular stru<ture. Iloweser, any modineations of the thoroughly inted end hate a long record of pnnen utin-Code deemed neecstary by these authorities should be factory performance. These w eldmg procedurci a nd jmnis cleart) referenced in the centrastual agreement between are designateJ m prequahned and may be used without the ow ner and the contractor.i tests or qualification a see .4.1 and $.2).
PrequahucJ pnaisions are ghen in Section 2. Prc.
quahned Joint Detaib: Scellon 3. Workmanship; and I.2. Ila50 M ClllU Secuon 4. Technique. Section 4 includes welding pro.
uduns, wkh spuine ufnenu to puheat. CHu metalt, The ASTM A6 and A20 specincations govem the de. electnde tire, and other pertinent requirementi. Ad.h.
hsery requirements for stech, proside for dimensional Honal nyu nunts for pnquaMeOoints in tubular cen.
toluanset, dehneate the quality requirements, and out. situction are ghen in Sution 10.
hne the type of mill condiuoning, %e uso of pnquahnd ) ints or i proecdures does not Material used for structural applicathms h usually for. necessanly guarantee sound welds, l'abrkation capability h nW Wub4 Immu w @ dathe anMnowledgeaW
- 1. As used in tha sommentar), contrator deognant the pany sselding supershion to comhtently prmfuce nound welds, responsibed for perforimng the welding under the Cafe. Th, term h used 6iitutlicly to ruvan contractor, fabewator. ereiter.
The Code de not prohibit the use of any welding manufsiturer. ete, . prWett. It slui imiweg no hmit.ition en the und of any othu I)pe o@nt not den it im[we any pnudural N.
- 2. On(e all steel tre660est'ont apprmed by the Cafe fot une
) in buddings, bridges, and tubular uructures are lated in it) 2.
the generet reiuont for opprmed baie meists w6tl be d6,.
neued in CIO 2. As an euertion, openfle prmitions apph.
tabte ont; to buildings or breJges are dmuned in Cil,2 or strkthint on any of the welding processes, it punida for the surptance of nush joints, welding pnicesset, and prmedures on the tuik of a successful quahueation by the contnictor Londusted in anoniance with the requirements
. C*s 2 respo met; of the Cnle(see 5.2),
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- 2. Design of Welded Connections 2.1.3 The engineer preparing contract design drawings 2.7.1 Minimum Fillet Weld Sizes for Prcqualified cannot specify the depth of groove (S) without knowing Joints. The Code specifies the minimum fillet weld size the welding process and the position of welding.he Code cnd requires that this size be made in a single pass.His is explicit in stipulating that only the effective throat (E) provision is intended to ensure sufficient heat input in is to be specified on design drawings for partialjoint pene. order to reduce the possibility of cracking in either the tration groove welds (2.1.3.1). This a!!ows the contractor heat-affected zone or weld metal, especially in a restrained to produce the effective throat by assigning a depth of joint. The minimum size applies if it is greater than the preparation to grooves shown on shop drawings as related size required to carry design stresses.
to his choice of welding process and position of welding. He intent of Table 2.7 is further clarified as follows:
ne root penetmtion will generally depend on the angle Base metal thickness of 3/4 in. (19 mm) and under.are 4$, ';7 subtended at the root of the groon in combination with the root opening, the welding position, and the welding pro.
exempt from preheat in accordance with Table 4.2. Should fillet weld sizes greater than the minimum sizes be re-quired for these thicknesses, then each individual pass of cess. For joints using bevel- and V groove welds, these factors determine the relationship between the depth of multiple-pass welds must represent the same heat input preparation and the effective throat for prequalified partial per inch of weld length a provided by the minimum fillet joint penetration groove welds. size required byTable 2.7.
2.5 Partial Joint Penetration - 2.8 Plug Welds and Slot Welds Groove Welds Plug and slot welds conform.ing to the d.imensional requirements of 2.8, welded by techniques prescribed in A pernal joint penetration groove weld has an unwelded Appendix A, and using materials appnwny 8.2,12 or portion at the root of the weld. This condition may also 10.2, am considered prequalified and may be used with-exist in joints welded from one ride without backing, and, ut perf nm,ng j int welding procedure qualification tests.
.l therefore, the Code considers them partial joint penetra-tion groove welds except as modified in Section 10 2.9.4-2.10.5 Corner Joint Dctails.The Ccde permits an (10.12.4). altemative option for preparation of the groove in one or l
The unwelded portions are no more harmful than both members for all bevel and J groove welds in comer
! those in fillet welded joints. These unwelded portions joints as shown in Fig. C2.9.4.
[
constitute a stress r'aiser having significance when fatigue his provision was prompted by lamellar tearing con-i loads are applied transversely to the joint.Ris condition siderations pennitting all or part of the preparation in the vertical member of the joint. Such groove preparation
_7 is reflected in the applicable fatigue criteria.
l s liowever, when the load is applied longitudinally, there reduces the residual tensile stresses, arising from shria.kage
- ,$ is no appreciable reduction in fatigue strength. Irrespec- of welds on cooling, that act in the through-thickness direc. -
tive of the rules governing the service application of thesc . tion in a single vertical plane, as shown in prequalified particular grooves, the eccentricity of shrinkage forces in cornerjoints diagrammed in Figs. 2.9.1 a nd 2.10.1. Here-relation to the center of gravity of the material will result fore, the probability of lamellar tearing can be reduced for
]2 k
y in angular distortion on cooling after welding.This same _
eccentricity will also tend to cause rotation in transfer of these joints by the groove preparation now permitted by the Code. However, some unprepared thickness. a" as axial load transversely across the joint. Derefore, means - shown in Fig. C2.9.4, must be maintained to prevent must be applied to restrain or preclude such rotation, both melting of the top part of the vertical plate.Ris can casily during fabrication a nd in service, be done by prepr. ring the groove in both members (angle ).
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CASE EXHIBIT 950 -
DESIGN OF WELDED STRUCTURES BY Omer W. Blodgett THE JAMES F. LINCOLN ARC WELDING FOUNDATION CLEVELANQ OHIO f
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Weldability and Welding Procedure / 7.2-3 preferred analysis listed'. Sulphur content of these steels TABLE 1-Preferred Analysis is usually below 0.033re, although the specification of Carbon Steel for Good Weldability limits permit as much as 0.0307.. ; 3,,,i s,,,,a;,, ,,, o,, ,,
". Continued progress is being made in metalhirgical Eiernent i h
"" b ,l the following Percentages
""**"**""*C
control of steel, as well as in the development of weld-ing processes, electrodes and fluxes. This tends to C""a c .o6 .:s .35 broaden the range of "weldability" with respect to steel [lS*"*** [" js aoy,,
analysis. 5,,,s,, s _c35 ,,,, .oso The six basic ASTH!-specification construction psois.,o,,, , .oso n,o, wo i steels usually do not require special precautions or special procedures.
ables'. a special procedure may not be requirco. or However, when welding the thi ~ cr plates in even m y wquim only a slight change from standard pro-these steels the increased rigidity . ud restraint and cedures and thereby minimize any increase in welding the drastic quench effect makes the use of the proper
' S
procedure vitally important. In addition, thick plates . i usually have higher carbon content.
For optimum economy and q dity, under either far r ble or adverse conditions, the weldmg procecure We also have an increase in the use of higher strength low alloy steels and the heat treated very high I T I ining ny type f steel should be based on the vield strength steels. These steels have some elements sel.s adual chemistry rather than the maximum alloy
~
e ntent allowed by the specificatwn. Tlus is because a in their chemistrv that exceed the ideal analvsis. Table mill,s average productwn nonnally nms considerably for high speed welding. ,
Frequentiv pre-planned and proven welding p o- unh dw maenum Ms x4 h & meemh cedures are reil uired to assure the production of crack- l'*"*Ily a Mill Test Report is available which gives tlw wec a.c analysis f any given heat of steel. Once free welds when joining thicker plates or the lov ~
this information is obtained. a weluing procedure can
- steels. These procedures usually call for one or a of the following: be set that will assure the production of crack-free welds at the lowest possible cost.
- 1. Proper bead shape and joint configuration.
1 Minimized penetration to prevent dilution of the weld metal with the alloy elements in the plate.
- 3. Preheating, controlled interpass temperature and 4. WELD QUALITY sometimes even controlled heat input from the welding procedure to retard the cooling rate and The main objective of any welding procedure is to join -
reduce shrinkage stresses. the pieces as required with the most efficient weld pos-sible and at the least possible cost. "As required" means
- 3. BASE PROCEDURE ON ACTUAL ANALYSIS the weld's size and quality must be consistent with the senice requirements. Excessive precautions to ob-Published standard production welding procedures tain unnecessarv quality. beyond that needed to meet generally apply to normal welding conditions and the service requirements, serve no practical purpose and
~
more common. " preferred analysi3 mild steels. can be expensive.
When a steel's specification analysis falls outside Because it greatly increases cost without any bene-the preferred analysis, the user often adopts a special fit. inspection should not request the correction of welding procedure based on the extremes of the ma- slight undercut or minor radiographic defects such as terial's chemical content " allowed" by the steel's speci- limited scattered porosity and slag inclusions unless fication. Ilowever, since the chemistry of a specific heat thorough study shows such defects cannot be tolerated of steel may run far below the top limit of the " allow- because of specific service requirements.
Why Welds Crack and How to Prevent it
- 5. WELD CRACKS
- 1. weld cracks occurring during welding, A crack in a weld, however, is never minor and cannot a cracking in the heat affected zone of the base be condoned. Good design and proper welding pro- metal, cedure will prevent these cracking problems: 3. welded joints failing in service.
", * . l 7.2-4 / oint Design and Production Plate is loter preheated.
and submerged-ore w id Hordened Tock weld well remelt tack welt zone in without and hardened zon, in base plate preheat j plate ja,%
hs Sh s
g (a) (b)
FIGURE 1 Fact:rs that Affect Weld Cracking During Welding Factors that Affect Welded Joints Failing in Service
- 1. Joint Restraint that causes high stresses in the Welds do not usually " crack" in service but may weld.
" break" because the weld was of insufficient size to
- 2. Bcad Shape of the deposited weld. As the hot fulfill service requirements. Two other factors would be:
weld cools. it tendt to shrink. A convex bead has suffi- 1. Notch tougimess.* which would affect the cient material in the throat to satisfy the demands of breaking of welds or plate when subjected to high the biaxial pull. However, a concave bead may result impact loading at extremely low temperatures.
in high tensile stresses across the weld surface from 2. Fatigue cracking
- due to a notch effect from toe to toe. These stresses frequently are high enough poor joint geometry. This occurs under service con-to rupture the surface of the weld causing a longitudinal ditions of unusually severe stress reversals.
crack.
An excessively penetrated weld with its depth j,, ,, ,, c ,,,,,,
greater than its width under conditions of hich restraint
~
rnay cause internal cracks. 1. Bcad Shape. Deposit beads having proper bead Both of these types of cracking are greativ aggra.
surface (i.e. slightly convex) and also l'aving the vated by high sulphur or phosphorus content in the proper width-to-depth ratio. This is most critical in the base plate. case of single pass welds or the root pass of a multiple
- 3. Carbon and Alloy Content of the base metal. pass weld.
The higher the carbon and alloy content of the base 2. Joint Restraint. Desien weldments and structure metal, the greater the possible reduction in ductility to keep restraint pmblems to a minimum.
of the weld metal through admixture. This contributes 3. Carbon and Alloy Content. Select the correct appreciably to weld cracking. grade and quality of steel for a given application.
- 4. Hydrogen Pickup in the weld deposit from the through familiarity with the mill analysis and the cost electrode coating, moisture in the joint, and contamin- of welding. This will ensure balancing weld cost and ants on the surface of the base metal. steel price using that steel which will develop the
- 5. Rapid Cooling Rate which increases the effect lowest possible overall cost. Further, this approach of items 3 and 4. will usually avoid use of inferior welding quality steels that have excessively high percentages of those elements Factors that Affect Cracking in the Neot-Affected that always adversely affect weld quality-sulphur and Zon? phosphorus.
- 1. High carbon or alloy content which increases Avoid excessive admixture. This can be accom-hardenability and loss of ductility in the heat-affected plished through procedure changes which reduce pene-zone. -(Underbead cracking does not occur in non- tration (different electrodes, lower currents, changing hard;nsble steel.)
- Neither notch toughness nor fatigue cracking are discussed w;Id metal. here. See Section 2.1, " Properties of .\!aterials," Section 2.8,
- 3. Rate of cooling which controls items 1 and 2. " Designing for Impact Loads, and Section 2.9, " Designing for Fatigue Loads."
~,
- e Weldability and Welding Procedure / 7.2-5 polarity, or improving joint design such as replacing cooling from the critical temperature results in a slightly a square edge butt weld with a bevel joint.) lower strength.
- 4. Hydro;;cn Pickup. Select low-hydrogen welding For the normal thicknesses, the mill has no materials.
difliculty in meeting the minimum yield strength re-
- 5. Heat Input. Control total heat input. This may quired. However, in extremely thick mill sections, be-include preheat, welding heat, heating between weld cause of their slower cooling, the carbon, or alloy passes to cor.'rol interpass temperature and post heat- content might have to be increased slightly in order ing to controi cooling rate. Control of heat input lowers to meet the required yield strengtn.
the shrinkage stresses and retards the cooling rate Since a weld cools faster on a thick plate than ca helping to prevent excessive hardening in the heat-arTected zone, two primary causes of cracking.
6, TACK WEl.DS A V The American Welding Society's Building Code and Bridge Specifcations both require any tack welds that A
will be inco orated into the Jnal joint, to be made under the sa.ie quality requirements, including pre-s M l l ,, ,,1 9#,%
heat, as the taal welds. ii""t
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However, this does not recognize the deep pene-tration characteristics of some welding processes, for
' example, submerged-are. If the initial tack welds are ',
relatively small compared to the first submerged.are weld pass, they will be entirely remelted along with (a) the adjacent heat-affected area in the plate.
In this case, no preheat should be required for 4 b sma!I single pass tack welds unless the plates are so thick and restrained that the tack welds are breaking.
See Figure 1. If the tack welds are breaking, the corrective measures previously listed relating to bead
{
shape and weld throat should be applied with pre- soft <e1 =
heating called for as a last resort. It is always a good j I idea to use low-hydrogen welding materials for tack
welding plates over 1 in. thick.
- 7. THINNER PLATE I f Welds that join thimler plates rarely show a tendency .bl Preset before weiding to crack. The heat input during welding and lack of mass of the t. inner plate create a relatively slow cooling rate. This. plus the reduced internal stresses A, y resulting from a good weld throat to plate thickness -
ratio and the fact that the thinner plate is less rigid and can flex as the weld cools and shrinks, controls A
the factors that induce cracking. Cracking is almost never a factor on thinner plate unless unusually high
.W j in carbon or alloy content. C a ( t 8 THICK PLATES '
In the steel mill, all steel plates and rolled sections landergo a rather slow rate of cooling after being (c) Weld free to shrink; stress-free rolled while red hot. The red hot thick sections, because of their greater mass, cool more slowly than thin
- sections. For a given carbon and alloy content, slower FIGURE 2
. . 1 1
l 7,2-6 / Joint Design and Production I a thinner plate, and since the thicker plate will prob-ably have a slightly higher carbon or alloy content, '
f welds on thick plate (because of admixture and fast ,
cooling) will have higher strengths but lower ductility than those made on thinner plate. Special welding '
/- g (o) (b) procedures may be required for joining thick plate " "*" ** !d (especially for the first or root pass), and preheating nr.y be necessary. The object is to decrease the weld's rat 3 of cooling so as to increase its ductility.
In addition to improving ductility, preheating .
- t thick plates tends to lower the shrinkage stresses that
'C) kj (d) develop because of excessive restraint.
Because of its expense, preheating should be r selectively specified, however. For example, fillet welds FIGURE 3 joining a thin web to a thick flange plate may n t require as much preheat as does a butt weld joini :
- 3. Upsetting the edge of the plate with a heavy two highly restrained thick plates. center punch. This acts similar to the rough flame-cut edge.
On thick plates with large welds, if there is metal.
to-metal contact prior to welCng, there is nu possibility The plates will usually be tight together after of plate movement. As the welds cool and contract, the weld has cooled.
all the shrinkage stress must be taken up in the weld, Fillet Welds Figure 2(a). In cases of severe restraint. this may cause the weld to crack, especially in the first pass on either The above discussion of metal-to-metal contact and side of the plate. shrinkage stresses especially applies to fillet welds. A By allowing a small gap between the plates, the slight gap between plates will help assure crack-free plates can " move in" slightly as the weld shrinks. fillet welds.
This reduces the transverse stresses in the weld. See Bead shape is another important factor that affects Figures 2(b) and 2(c). IIeavy plates should always fillet weld cracking. Freezing of the molten weld, have a minimum of W" gap between them, if possible Figure Sia), due to the quenching effect of the plates commences along the sides of the joint (b) where the
%". cold mass of the heaw plate instantly draws the heat This small gap can be obtained by means of:
- 1. Insertion of spacers, made of soft steel wire out of the molten weld metal and progresses uniformly between the plates. The soft wire will flatten out as inward (c) until the weld is completely solid (d).
the weld shrinks. If copper wire is used, care should Notice that the last material to freeze lies in a plane be taken that it does not mix with the weld metal. along the centerline of the weld.
- 2. A deliberately rough flame-cut edge. The small To all external appearances. the concave weld peaks of the cut edge keep the plates apart. yet can .a) in Figure 4 would seem to be larger than the squash out as the weld shrinks. comex weid t hi. Ilowever. a check of the cross-FIGURE 4 l
4 A
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(c) Concave Met weld (b) Conven weld I
l Weldability and Welding Procedure / 7.2-7 section may show the concave weld to have less pene- weld to freely shrink (dotted lines). Then pull the ,
tration and a smaller throat (t) than Erst thought: plates back to the original rigid position that they therefore, the convex weld may actually be stronger would normally be in during and after welding (solid even though it may have less deposited metal (darker lines). This necessitates a stretching of the weld.
cross-section). f Designers originally favored the concave fillet weld ,
because it seemed to offer a smoother path for the flow of stress. IIowever, experience has shown that single- 4-l-
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pass fillet welds of this shape have a greater tendency h
' C h to crack upon cooling, which unfortunately usually outweighs the effect of improved stress distribution.
FIGURE 6 This is especially true with steels that require special welding procedures.
When a concave fillet weld cools and shrinks, its In etual practice all f this stretch or yielding C"" CC"' nly in the weld. since the plate cannot outer face is stressed in t nsion, Figure 5(a). If a surface shrinkage crack > .ould occur. it can usually be m ve and t..9 weld has the least thickness of the joint.
avoided by changing to a convex fillet (b). Here the .\f st of this yielding takes place while the weld is hot and has lower strength and ductility. If, at this time, the internal stress exceeds the physical properties of the weld. a crack occurs which is usually down the centerline of the weld.
I surface n ms.on % surface not in tens.on The problem is enhanced by the fact that the
- i first (or root) bead usually picks up additional carbon i l R or allov by admixture with the base metal. The root hg*
bead titus is less ductile than subsequent beads.
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A concave bead surface in a groove weld creates the same tendency ror surface cracking as described (a) Concave weld (b) Convex fUlet weid for fillet welds, Figure 7. This tendency is further increased with lower ductility.
FIGURE 5 weld can shrink, while cooling, without stressing the outer face in tension and should not crack. For multiple-pass fillet welds, the convex bead shape usually applies only to the first pass.
For this reason. when concave welds are desired I i i I for special design considerations, such as stress flow. Wrong Lgnt they should be made in two or more passes-the first Teo concave Fict or sngntly conver slightly convex, and the other passes built up to form FIGURE 7 a concave fil:et weld.
- 9. GROOVE WELDS Increasing the throat dimension of the root pass will help to prevent cracking; use electrodes or pro-On heavy plate, it is usually the first (or root) pass cedures that develop a convex bead shape. Low hydro-of a groove weld that requires special precautions. This gen welding materials are sometimes useful and finally 1 is especially.true of the root weld on the back side of preheat can be specified. Obviously preheating should I a double Vee joint because of the added restraint from he adopted as a last resort since it will cause the !
th3 weld on the front side. The weld tends to shrink in greatest increase in weld cost.
all directions as it cools, but is restrained by the plate. The problem of centerline cracking can even l Not only are tensile shrinkage stresses set up within the occur in the succeeding passes of a multiple pass weld '
weld, but the weld frequently undergoes plastic yield- if the passes are excessively wide or concave. Correc-ing to accommodate this shrinkage. tive measures call for a procedure that specifies a Some idea of the possible locked-in stress and narrower slightly convex bead shape making the com-plastic flow of the weld may be seen in Figure 6. pleted weld two or more beads wide, side by side, [
Imagine the plate to be cut near the joint, allowing the Figure 8. -
I
r-q
. , * .' , a i
7.2-8 Joint Design and Production I
~
O ,
l l 7 I I i Wrong Wrong Right FIGURE 8 Too wide and cormove Washed up too high Flot or slightly convex (Also poor slog removoll and concave not quite full width (Also good slog removoQ
- 10. INTERNAL CRACKS AND WELD WIDTH to a maximum of 1.4 to 1.
TO DEPTH OF FUSIC N RATIO Width of Weld = 1 to 1.4 Depth of Fusion Where a cracking problem exists due to joint restraint, material chemistry or both, the crack usually appears at the weld's face. In some situations, however, an W w.m W ~ we L internal crack can occur which won't reach the weld's ,
face. This type of crack usually stems from the mis- 3 use of a welding process that can achieve deep pene- + ~; yg *: "" *
~ ;: l p -+
tration, or poor joint design.
8'
/
d, '
f y
The freezing action for butt and groove welds is I the same as that illustrated for fillet welds. Freezing starts along the weld surface adjacent to the cold base c ,,,
w..a - w.ia w.id metal, and finishes at the centerline of the weld. If, w.,4 ..
however, the weld depth of fusion is much greater than (,)
width of the face, the weld's surface may freeze in advance of its center. Now the shrmkage forces will act on the still hot center or core of the bead which could cause a centerline crack along its length without this crack extending to the weld's face, Figure 9(a). g o a' as' Internal cracks can also result with improper joint design or preparatica. Figure 9(b) illustrates the dL k
8\
results of combining thick plate, a deep penetrating (b) welding process, and a -15' included angle.
A small bevel on the second pass side of the ,-*=9-9.'=-- ,.-*=<=
double-V-groove weld. Figure 9(c), and are gouging 3 j/g ; y -(
-(_, y
=_ g g~ - -
a groove too deep for its width, led to the internal crack illustrated. .%
Internal cracks can also occur on fillet welds if f A"' fT ,g,3'
~
f the depth of fusion is sufficiently greater than the face width of the bead, Figure 9(d).
(c)
Although internal cracks are most serious since they cannot be detected with visual inspection methods, a few preventive measures can assure their elimination.
Limiting the penetration and the volume of weld metal %g.o,n deposited per pass through speed and amperage con-trol and using a joint design which sets reasonable
\N' -
N.
depth of fusion requirements are both steps in the right direction.
In all cases, however, the critical factor that helps ' Q* 'J"
' (d) control intemal cracks is the ratio of weld width to s depth. Experience shows that the weld width to depth of fusion ratio can range from a minimum of I to 1 - FIGURE 9 w._
W Idability and Welding Procedure / 7.2-9 l
- 11. UNDERBEAD CRACKING drogen tends to pile up here, going no farther. See Figure 10.
Underbead cracking is not a problem with the con- Upon further cooling, the heat-affected area trans- ;
trolled analysis low carbon steels. This problem if it forms back to ferrite with almost no solubility for hy-occurs is in the heat-affected zone of the base metal. drogen. Any hydrogen present tends to separate out It can become a factor with thick plate as the carbon between the crystallattice and builds up pressure. This ,'
or alloy content of the steel increases. As an example pressure, when combined with shrinkage stresses and 6 this can occur with the heat treatable very higa any hardening effect of the steels chemistry, may strength, high carbon low alloy steels like 4140 or cause tiny cracks. Since weld metal is usually of a 6150. The construction alloy steels which have over lower carbon than the base plate, this trouble occurs 100,000 psi tensile strength and are heat treated before mainly just beyond the weld along the austenite.
welding, also can experience underbead cracking in ferrite boundary and is called "underbead cracking' thick plates. When armour plate was used, underbead See Figure 11. If some of these cracks appear on the cracking (tce cracks) was a problem. The point is that tha problem is only important on hardenaale steels.
Low hydrogen processes should be used to join 4 b these materials since one cause of underbead crack- ,
ing is hydrogen embrittlement in the heat.affected ,' . Weld zone. Hydrogen in the welding arc, either from the electrode coating or from wet or dirty plate surfaces.
//f will tend
- be partially absorbed into the droplets l 'f/
- // /
yoe crack of weld mual being deposited and absorbed into the molten metal beneath the arc.
y g //M y
( ---;. ' <
As the welding are progresses along the plate, tha deposited hot weld metal (which has now solidi. undertseod crack fled) and the adjacent base metal heated by the weld above the transformation temperature are both aus-
), f tenitic at this elevated temperature, and have a high FIGURE 11 solubility for hydrogen. Fortunately, a considerable amount of hydrogen escapes through the weld's sur- plate surface adjacent to the weld thev are called " toe face into the air; however, a small amount may diffuse cracks'. Slower cooling by welding slower and pre-back through the weld into the adjacent base metal.
heating allows hydrogen to escape and helps control (The rate of diffusion decreases with decreasing this problem.
temperature.)
The use of low-hydrogen welding materials clim-inates the major source of hydrogen and usually eliminates underbead cracking.
- 12.
SUMMARY
ON CRACKING ttttift, werd J,, L Adiocent piore transforrned The first requirement of any welded joint is to be i \r
- [A f +TCkhY 1 ', to /
custenire wna. heered crack-free. Cracking may occur in either the weld
'~
by weid: hydrogen is metal or the heat.affected zone of the base plates.
y . solubie in this region Most steels can be welded in the average plate s thickness without worrving about weld cracking.
d fr e any fur er err $teYo sNut I As plate thickness increases, and as the carbon for hydrogen and alloying content increase, weld cracks and under-bead cracks may become problems and require special precautions for their control. .
This necessitates in order of importance: a) <;ood FIGURE 10 welding procedure, especially in respect to bead shape, control of admixture, b) reducing rigidity by inten- .
Beyond the boundary of the heat-affected zone, tional spacing of plates, c) use of low-hydrogen weld- ;
tha base metal is in the form of ferrite, which has ing materials, and d) controlled cooling rate, including
- practically no solubility for hydrogen. This ferrite welding current and travel speed, and if needed con-boundary becomes an imaginary fence, and the hy. trol of preheat and interpass temperature.
. ~.
- 7.2-10 / hi;t Desiga cnd Prodztia Why Preheat and How to Determine Correct Preheat Temperature 13, WHEN AND WHY TO PREHEAT T. (,F)
R,, (,F/sec) l Preheating. While not always necessary, is used for one - 58 6.8 - 9.9 of the following reasons- 6a a.6 - t i.7
- 1. To reduce shrinkage stresses in the weld and 2i2 21.6 - 37.8 adjacent base metal; especially important in highly restrained joints. 5. To increase the notch toughness in the weld
- 2. To provide a slower rate of cooling through the zone.
critical temperature range (about 1S00* F to 1330' F) 6. To lower the transition temperature of the weld preventing excessive hardening and lowered ductility and adjacent base metal.
in both weld and heat-affected area of the base plate. Normally, not much preheat is required to prevent
- 3. To provide a slower rate of cooling through underhead cracking. This is held to a minimum when the 400'F range, allowing more time for any hydrogen low-hydrogen welding materials are used. Iligher pre-that is present to diffuse away fmm the weld and heat temperature might be required for some other adjacent plate to avoid underbead cracking. reason. e.g. a highly restrained joint between very
- 4. To increase the allowable critical rate of cooline thick plates, or a high alloy content.
below which there will be no underbead crackine. Preheating makes other factors less critical. but Thus with the welding procedure held constant. a .since it invariably increases the cost of welding, it higher initial plate temperature increases the maximum cannot be indulged in unnecessarily.
safe rate of cooling while slowing down the actual rate of cooling. This tends to make the heat inpu:
from the welding process less critical. 14. AWS MINIMUM REQUIREMENTS Cottrell and Bradstreet* show the following critical cooling rates (IL,) for a given steel at 572*r (300'C) The AWS has set up minimum preheat and interpass using low-hydrogen electrode in order to prevent under. requirements given in Table 2.
bead cracking for various preheats to be: These minimum preheat requirements may need to be adjusted, according to welding heat input, spe.
- Cuttrell and Bradstreet. "Effect of Preheat ou Weldabihty",
cif c steel chemistry, the joint geometry, and other BRITISil WELDING JOURNAL, July 1955, p. 309. factors.
TABLE 1-AWS Minimum initial and Interpass Temperatures" (1966)
Welding Frecess Shielded Meta 6-Arc Welding with geknen of shieided Metoi-Arc Welding with Low. Hydrogen Electroces
"'#""' Other tnan Low-Hyd< ogen Electrooes and Submerged Arc Welaing Point of Welding M6 ', A7', A373' A36*, A7*, A373*, A441' U"*h"I g A242' weidable Grooe To %, incl. j none' { none' Over % to IW, incl. l 150*F l 70*F Cver IW to 2%, incl. 225'F l 15C*F Over 2% 200*F l 225'F
' Welding shall not be done wnen the amoient temperature is lower than 0*F.
8 When the base eneral is below the temperature hated for the weiding process br' ;, us*<i and the thickness of material being welded, it shall be preheated for both tack welding and welding in such montier that the surf aces of the parts on which weld metal is being deposited ore at or above the soecified minimum temperature for o distance equal to the thickness of the part being welded, but not less than 3 inches, both lateroily and in advance of 'he welding.
Preheat temperature shall not exceed 400*F. linterpass temperature is not subject ta a maximum limit.)
'Using f60XX or E70XX electrodes other than the low-hydrogen types.
' Using E60XX or E70XX low-hydrogen electrodes (EXXt5, -16, .18. 28'- or Grade $AW.I or SAW 2.
"Using only E70XX low-hydrogen electrodes (E7015, E70to. E7018, E7028) or Grade $AW-2.
- When the base metal temperature is below 32*F , preheat the base metal to at teost 72*F.
. . i 1
W;ldibility c:d W;ldi:g Procedure / 7.2-11
- 15. HEAT INPUT DURING WELDING
'n I One factor that would reduce preheat requirements N '
F C'
is the use of greater welding heat input; for example, j 's, hI'" H '" 5 the welding heat input for vertical welding with weave { ,
passes at an are speed of 3 in./ min. is greater than that e -- h--- -- - -- Coohng rate *F/sec of horizontal welding with stringer beads at 6 in./ min. ? Pr y The heat input (J) for a specific welding procedure b
- M*(,
can be determined using the formula: --
I' ** *
} = E 1y 60............................(1) FIGURE 12 whenn cation uses a single-are, submerged-are automatic weld J = Heat input in Joules /in. or watt sec/in. at S50 amps and a speed of 20 in/ min. (for a %" fillet E = Arc voltage in volts weld), with the girder positioned for flat welding. This I = Welding current in amps would provide a heat input of S6.000 joules /in. An V = Arc speed in in./ min alternate method positions the girder with its web vertical so that both welds are made simultaneousiv in Since all of the welding heat input at the are does the horizontal position. and uses two sets of tanciem not enter the plate. the following heat ediciencies are ares teach set with two weldine heads); the heat input
- suggested for use with this formula and subsequent from each are would be 73.600 joules /in.-a total of formulas. charts or nomographs
- 147.000 joules /in. of weld for each fillet. Because of the 75-50% manual welding resulting lower cooling rate. less preheat should be required once the weld has been started. This may be 90-100% submerged are welding a considerable advantage for the comfort of welding
.\fost preheat and interpass temperature recom. E ' "' "E " '" " "E I" E "*
mendations are set up for manual welding where there is a relatively low heat input. For example. a current of 16. COOLING RATE 200 amps and a speed of 6 in./ min. would produce a welding heat input of about 4S.000 joules /in. or watt. When a weld is made. the weld and adjacent plate see. fin., assuming an efficiency of 50 percent. Yet, it cool very rapidly. The rate of cooling depends frst might be necessary to weld a 12-gauge sheet to this on the combination of initial plate temperature (T.)
plate in the vertical down position with ISO amps and (including effects of preheat or interpass temperature) a speed of 22 in./ min. This would reduce the weldmg and the welding heat input (J), and secondly, on the heat input to 9500 joules in. If this were a thick plate. plate's capacity to absorb this heat in terms of plate it would indicate the need. with this second pro. thickness and joint geometry, cedure for more preheat, although existmg preheat Figure 12 illustrates the temperatures in the heat.
tables do not recoenire the effect of different weiding a:Feeted zone of the plate as the welding are passes heat inputs. by. Under a given set of conditions. the cooling rate On the other hand. some downward adiustment wd! vary as represented by the changing slopes of in preheat from the value listed in the preheat tables both curves.
should he made for standard welding procedures For a particular chemistry, at a given temperature which provide a much greater welding heat input. level (T ) there is a critical cooling rate (Ib) which i
We are considenng here a stable heat-ilow condition should not be exceeded in order to avoid underbead aftcr some welding has progressed. cracking. This temperature level is in the range of This does not consider the more severe cooling 400'F to 750*F. American investigators tend to use a conditions at the moment welding commences. Un. higher value such as 750', while English and Canadian doubtedly, some initial heat could be supplied to a investigators favor a lower value such as 300'C, or localized area at the start of the weld on thick plate. 572'F. In this discussion, we have placed this tempera.
The question now becomes how much, if any, pre. '
ture level (T ) at 572*F.
i he:t is needed for the remaining length of joint. The investigation of cooling rates has been based [
For example it is standard practice today to use largely on two extreme conditions, which have been i submerged-are aatomatic welding to build up columns developed mathematically.' These are:
and girders from heavy plate. One method of fabri. 1. The thin plate, in which the combination of
7.2-12 / Joint Design and Production bzt input and plate size permit assuming the temper. K2 = constant, representing K at T i ature to be uniform throughout the thickness at any (K. = 5.961 for mild steel at 572*F)
~
point; in other words, heat flows transversely in only two axes. See Figure 13. P = density, lbs/ft*
(p = 4S9.6 lbs/ft8for mild steel)
C = specific heat, BTU /lb/*F Mb (C = .136 BTU /lb/'F for mild steel) 4- 4 6'. .ii }.
t = actual plate thickness, in.
FIGURE 13 J = welding heat input (formula 1) i thin plate 1.*nfortunately, there is no clear definition of what is a " thin plate" and what is a " thick plate" relative t c ling rate. The actual condition often lies some-R=K i N
\J/(T - T.)*
.......... .(2) where between these two extremes, and for this reason a certain amount of judgment is needed. For example,
- 2. The thick plate, in which the combination of welding on a 1" plate with submerged are at a current heat input and plate size permit assuming the bottom of 1000 amps and a speed of 10 in./ min. would ap.
surface of the plate does not increase in temperature:
proach a " thin plate" condition: yet manual welding m other words. heat flows transversely m, three axes.
vertically down on a si" plate at a current of 120 a nos See Figure 11.
and a speed of 12 in./ min. would approach a "!' $k plate" condition.
In Figure 15, these two basic formulas are plotted
/f0,3 for a given set of conditions: heat input (J), and pre.
- g , jzij
- heat and interpass temperature (T.).
'(
\' y _'.g '
(
f d f
l l Thm Ll l l l Mformulo ;
l l 1 l i , l l 1 W
FIGURE 14 2 L
IIb ,
I I l Thick E I I
thick plate 5 *"""'*
3 1 / i l I i ! i R = b(T - T.): ...................(3)
I ! !! I I d / I l I ! ! !{
wiiere: [/l i i l i i ! 6 i R = cooling rate at temperature t T ), 'F/st'C i P! ate tmcaness p)
- T = temperature at which cooling rate is con.
i sidered. 572*F FIGURE 15 T. = initial plate temperature or preheat tempera-ture when preheating is used, 'F The formula for a " thin plate" recognizes the effect of plate thickness (t); and the resulting cooling rate K = thennal conductivity (the BTU loss per hour (R) increases rapidly as the square of the plate per square foot of surface divided by the thickness. When the cooling rate characteristics of a temperature gradient of 'F per foot of thick plate are studied. however, it soon becomes ap-thickness.) parent that for a given welding procedure and an (K = 25.9 for mild steel at 572*F) initial temperature. increasing the plate thickness be-K = constant, representing K, p, C at T i
y nd a certain dimension will not cause further change in the rate of cooling. For this reason, the formula for (K = 161.48 for mild steel at 572*F) " thick plate"-Formula No. 3-does not include actual
- D. Rosenthal. " Mathematical Theory of Heat Distribution plate thickness (t) and the value of (R) does not During Cutting and Welding", WELDING JOURNAL. May vary with thickness but remains constant for a given 1941, p. 220-s.
Weidability and Welding Proc: dure / 7.2-13 heat input, preheat and interpass temperature. For a lotccr portion !'
given heat input, the cooling rate indicated by the '
T.,'. 3
" thick plate" formula is the maximum (R.) that can J.-- = T' -
..............(6) occur regardless of the plate thickness. t- T-i T.
At any given plate thickness the lower cooling +
rate value is the more nearly correct. Using the tw r pion curves of Figure 15 as a limit and a guide, a new curve (solid line) has been drawn in Figure 16.
. . r .
Ct
- i[TTi- -T./.,[
i T. \
f l t l l l Resulhng coonng rate 1
~
Ti - T /..
T - T.
i
- N f
P,
,f f
curve for vanous -
e , .(. .piote thicknesses where:
l gl l f "----h E' '
t = actual thickness of the plate, in.
t.. = maximum effective plate for given values of 3~ l l (J) and (R) jf i I l I i l i Plore thickness (t) *-+ t.e .4340 ***********************(b)
FIGURE 16 T = elevated temperature at which cooling rate i
Notice. Figure 16. that the upper half of the is considered (572'F) variable part of this curve is almost a perfect reversal of the lower half, and the lower half belongs to the T., = preheat temperature for given values of (J),
curve for the " thin plate". Therefore, the curved por- (R), and (t), 'F tions will be expressed mathematically as- TJ = maximum effective preheat temperature for lotccr portion R = 161.4S (572 - T.)8 .........(4)
T - Td.. =
i 5.961 upper portion Formulas (6) and (7) produced the curve shown in Figure 17. This can be used to determine T. the R = 5.961 *N- 27.09 t: 572 - TJ required preheat temperature.
J \ J 572 - 1.
- I4"_, t y
-1 17. BI-THERMAL VS. TRI-THERMAL HEAT
- FLOW
.....(5)
This work is based upon bi thermal heat flow where If a welding procedure for a given plate thickness the heat las two avenues for escape; for example, a hes in the lower portion of the curve, it is easy to solve conventional butt joint consisting of two plates. Figure directly for the required preheat (T.) using formula 13(3)'
(4); however, this would be very difficult for the Tri-thermal heat flow has three avenues for escape.
upper portion using formula (5).
The chart is further limited in use since it only an examp! is a tee j int m de of three plates. Figure covers a single value of preheat and heat input. There*
I8S)*
Where tri-thermal heat flow condition exists, the f:re, to expand the application of this approach, we above work should be modified either by:
will put both formulas (4) and (5) into more usable '
j non-dimension formulas (6) and (7). This calls for 1. Using % of the actual heat input (J), or inclusion of the maximum eficctive plate thickness 2. Adjusting the plate thickness (t) to allow for i (t ), and the corresponding maximum effective pre- the extra plate by using % of the sum of three heat (Td ) for this thickness. thicknesses.
l l
6
~. '.
7,2-14 / Joint Design and Production 7
1.0f
~*
l l 14 I l l l I/ _,_ ,, T, - T_;, _1 ,/ _ T, - T.
.7 f t T, - T. ,
' r2 'Ti-T T. - T , l/
A l
Upper portion of curve T, - T.
[
.4 -
i r i
.3 "-1 II i I
, , i 'T i - T. 12 l
.2 g,= 2 , T, - T,] FIGURE 17
.1 . Lower port.on of curve
[l l I l l l l
.1 .2 .3 .4 .5 .6 .7 .8 .9 1.0 1.1 1.2
..L t.
p _
D ; y E6015 electrode is comparable to today's E701S. The results were plotted. Figure 20. to give curves for three different preheat temperatures (T.,).
+ K. Winterton* has listed 14 different carbon eq uvalent formulas and recommended the following:
. Ni% . CrG . Tion C,,i = C% + .\ln% 6 ~ 20 '
10 50 b\ VG Cu% .(10) 10 - 40 (b) e' ; :
f FIGURE 18 This formula is applicable to the low-carbon low-alloy steels for construction and machinery manu-f cturing.
- 18. CARBON EQUIVALENT As a result of recent experiments and studies, it is 19. COOLING RATE AND CARBON possible to simplify the relationship of all chemical EQUIVALENT clements in a steel to the occurrence of underbead crackint:. The simplificanon is expressed in a sinule Although not too well defined. for a given analysis formula kn<mn as the carbon equivalent. This formula of steel there is a maximum rate at which the weid expresses the influence of each element relative to that and ad.iacent plate may be cooled without underbead of carbon. cracking occurnng.
Investigators
- have shown a definite relationship
' K. Winterton. "Weklabihty Prediction from Steel Ccmpo.
m the percent of underhead cracking to the carbon sidon to .hoid IIcat-Affected Zone Cradin g", WELDING equivalent. Figure 19 shows a 1" thick test plate on Jot'RNAL. June 1961. p. 253-s.
which a single bead was deposited using t's" E6010 electrode at 100 amps. 25 v, reversed polarity, at 10 in./ min. The chart. Figure 20. shows the percentage 4" of underbead cracking for different carbon equivalents fl%"$ p1~1 that occurred with this test. A deposit made with low-hydrogen E6015 electrodes on a specimen of this p , ,
j ,,,, ___ e ___ p__ _ 3,, ,,,
thickness did not have underbead cracks. The AWS
- Stout and Doty, "Weldability of Steels", Welding Research i' Council.1953, p.150; Williams, Roach. Martin and Voldrich,
. "Weldabihty of Carbon-Manganese Steels", WELDING JOUR-NAL, July 1949, p. 311-s. FIGURE 19
, I j
W;ldibility rad Weldixg Proctdurs / 7.2-15 !
The higher the carbon equivalent. the lower will carbon equivalent-critical cooling rate curve shown ;
be this critical (allowable) cooling rate. Thus, the in Figure 21 has been produced to use as a guide in higher the steel's carbon equivalent, the more im- case the CTS test on the particu!ar steel is not made.
portant becomes the use of low-hydrogen welding and This curve may be expressed by E.e following formula:
preheating.
Cottrell and Bradstreet* have used a type of R,, = 6.598
............(11)
Reeve Restraint test, called the CTS (Controlled C., .30 74 - 16.2t Thermal Severity) test. For any given steel, three thick- This is the critical cooling rate at T - 572'F.i nesses are tested - %, %, and 1". Each test requires The critical cooling rate (Ry) can be determined by a) actual test of the particular steel to see what cooling rate will not cause cracking, or b) using 100.. , formula (11) based upon Canadian investigations.
l l ' '7g.,I
.70_
- l g -150*F 6.578
-t- C" = R + 16.26 + *3074
.-p 80'-
6 l l I l l _
C., .3074 --
l I I l .
! $25'F d 3 ,O '
I : ! ; I j/ ! ! i .60-su99 s'eo re'or'oa oe'-eea crincoi coo"a9 ro'e i'l oao
- =rcon ecuivorent #C,,) for sow-nvarogen e ectroces
! 20 <
'E
! l 1
~?
O volves from A C
.40 57.6 j i 1, B .45 36.0 l 6 l l i l
.50 " C .50 19.8 0 .20 40 .60 30 .100 8
Coroon equivoient. C., = C + $ + f 5 -?)-- F .65 3.6 FIGURE 20 V
{ l 1 i'
f I ! :
two fillet welds--one a bi-thermal weld (two avenues 40" l % l for heat to escape), the other a tri. thermal weld (three avenues for heat to escape). This gives a total of 6 different values for TSN (Thermal Severity Num- ; i i 5 ber), and for the given welding heat input (about t i ! !
32.000 joules /in.) produces 6 different cooling rates. ,
~3 i .
i It is then observed at what cooling rate cracking a 10 :0 30 ao 50 e: rc does or does not occur, and the subsequent welding Cnnco, coo;,ng rore g). c .iec procedure is adjusted so this critical cooling rate will FIGURE 21 not be exceeded.
Both of these men have produced tables in which relative weldability has been expressed along with 20. FINDING REQUIRED PREHEAT the critical cooling rate. .\ lore recently, Bradstreet** TEMPERATURE has tied in this relative weldability with carbon equiva-To calculate the required preheat temperature (T )
lent. By working back through this ir. formation, the that will produce the required cooline rate i R) for
- C. L AI. Cottrell, Controlled Thermal Severity Cracking Test a gisen heat input (D and plate thickness (t), the Simulates Practical Welded Joints". WELDING JOURNAL, following mathematical computations must be made:
June 1933, p. 257-s; Cottrell and Bradstreet, "A h!ethod for a) Determine from formula (9) the value of Calculatmt: the Effect of Preheat on Weldability" BRITISil WELDING JOURNAL, July 1955, p. 305; Cottrell and Brad- (T -- T b).
street, " Calculating Preheat Temperatures to Prevent liard b) Determine from formula (S) the value of Zone Cracking in Low Alloy Steels", BRITISH WELDING ( t..) .
JOURNAL, July 1955, p. 310. c) From this (b) determine '(t/t,,, ).
, ** B. J. Bradstreet "Alethods to Establish Procedures for Weld- d) From the chart, Figure 17, using (c) read the r l ins Low Alloy Steels", ENGINEERING JOURNAL (Engineering Instaute of Canada), November 1963. value for 8
7.2-16 / Joint Design and Production l
- T./"* Example Using Nomograph (Fig. 22)
! e) Knowing this value (d) and the value of (Ti - T./ ) from item (a), determine the Given: J = 20.000 mch "?'"
required preheat temeprature (T.). R = 25 'F/see An easier and faster method for determining the required preheat uses the nomograph, Figure 22. This t = 1.0*
nomograph is actually two nomographs superimposed find preheat temperature (T.):
ur m each other. The first nomograph (subscript a) wf! provide a value for Ti - T./..
T i - T.,
M rnh The second nomograph ( bscript b) will provide the (1) R = 25 *F/see required preheat and interpass temperature (T.). watt-sec A set of eight graphs, Figure 23, will also provide (Sa) J = 20,000 inch this same information.
(3a) read t., = 126*
Exemple Using Chart (Fig.17) Use this number as a pivot point Given:
~ T. m. = 733 watt.s 52) Read %
J - 2000 mch n = 25 'F/sec 2nd nomograph t = 1.0' (1) R = 25 *F/see find required preheat temperature (T.): *~"
(2b) J = 20,000 ** inch a) /RJ Determine T - T./ = 15.961 1
(3b) Read T./.. = 2S2 *F
_ (25) (20,000) Use this number as a pivot point a.961
- 'S9.6' F (4b) % ITi *',"* = 73% (from 1st nomograph)
- T.
b) Determine t., = .42457 (5b) Read T. = 175 'F
- 120.000 21. OTHER POINTS OF CONSIDERATION
= ,42457 N 2o
= 126* Test data has indicated that thin plates result in slightly higher cooling rates than calculated. It is 1
c) Determine relative thickness: t =,,,,0., believed this is because thin plates have a relatively
- ~~
greater surface area for heat loss per volume than
= 4429 thick plates.
d) From chart, Figure 17, read relative preheat Normally, in the investigation of a groove weld.
'- * ** = .73 the pass completing the joint is considered rather than temperature:
Ti - T. the root pass. This is because the face pass usually has 2S9.6 a slightly higher cooling rate due to the larger cross-e) Therefore: T - T. = Ti ,73 i - T./.. =
,73 section of the joint (assuming the same interpass temperature).
=OE There is some indication that fillet welds have 572 - T. = 396.7 slightly higher cooling rates than the bead-on-plate welds used in the investigative work. This is because or T. = 175.3 'F the 90' intersection of the two plates presents a larger area of contact with the weld, therefore absorbing e heat at a slightly greater rate. A groove weld similarly would offer a larger area of plate contact with the weld than a bead on plate weld.
~
a >
CASE EXHIBIT 97/ I Structural Welding Code Prepared by AWS Structural Welding Committee Under the Direction of AWS Technical Activities Committee Approved by AWS Board of Directors. June 16, 1975
\
'N_
AMERICAN WELDING SOCICTY, INC.
2501 N.W. 7th Street, Miami, Fla. 33125
- 4. Technique Part A General 4.1.5.4 Flux Cored Arc Welding. Single pass fillet welds up to 5/16 in. (8.0 mm) maximum and groove welds made with a single pass or single pass each side 4.1 Filler Metal Requirements may be made using an E70T-X electrode.
4.1.6 For electroslag and electrogas welding of ex-4.1.1 The electrode electrode-Dux combination, or posed, bare, unpainted applications of ASTM A242 Frade of weld metal for making complete joint and A588 steel requiring weld metal with atmosphene penetration butt welds shall be in accordance with corrosion resistance and coloring characteristics Table 4.1.1. similar to that of the base metal, the mechanical 4.1.2 The electrode electrode flux combination, or properties of the weld metal shall meet the re-grade of weld metal for complete joint penetration or quirements of Table 4.20 and the chemical composi-partial joint penetration groove welds and for fillet tion requirements of Table 4.1.4.
welds may be of a lower strength than required for complete joint penetration butt welds provided the weld metal meets the stress requirements (see 8.4,9.3, or 10.4, whichever is applicable). 4.2 Preheat and InterPass 4.1.3 After filler metal has been removed from its Temperature Requirements original package, it shall be protected or stored so that its characteristics or welding properties are not With the exclusion of stud welding (see 4.28.7) and affected, electroslag and electrogas welding (see 4.24.5), the minimum preheat and interpass temperatures shall be 4.1.4 For exposed, bare, unpainted applications of in accordance with Table 4.2 for the welding process ASTM A242 and A588 steel requiring weld metal-being used and for the higher strength steel being with atmospheric corrosion resistance and coloring welded. Welding shall not be done when the ambient characteristics similar to that of the base metal, the temperature is lower than 0 'F (-18 *C). (Zero *F does electrode, electrode-flux combination, or grade of not mean the ambient environmental temperature but weld metal shall be m accordance with Table 4.1.4. in the temperature in the immediate vicinity of the weld.
multiple pass welds, the weld metal may be depos,ted i so that at least two layers on all exposed surfaces and edges are deposited with one of the filler metals listed Table 4.1.4-Filler metal requirements for in Table 4.1.4, provided the underlying layers are exposed bare applications of ASTM A242 deposited with one of the filler metals specified in and A588 steel Table 4.1.1.
4.1.5 For single pass welding, other than electroslag or WELDING PROCESS clectrogas, of exposed, bare, unpainted applications of Gas metal arc ASTM A242 and A588 steel requiring weld metal Shielded Submerged or with atmospheric corrosion resistance and coloring metal are arc Flux cored are'
- characteristics similar to that of the base metal, the AWS A5.5 AWS AS.23
, following variation from Table 4.1.4 may be made: E8016 or 18-C' 2 F7X-EX X X.W'
- i 4.1.5.1 Shicided Metal Arc Welding. Single pass E8016 or 18-B12 F7X-EXXX.B18 ' 62 ksi min YP fillet welds up to 1/4 in. (6.4 mm) maximum and 1/4 E8016 or 18-B22 F7X-EX X X.B22 ' (430 MPa) in. groove welds made with a single pass or single pass E8015 or 18-B212 72 ksi mints cach side may be made using an E70XX low. hydro. E8016 or 18-CI F7X.EXXX-Nil' (495 MPa) gen electrode. E8016 or 18-C2 F7X-EXXX-Ni2', Elon.18% min 4.1.5.2 Submerged Arc Welding. Single pass fillet E8016 or 18-C3 F7X.EXXX-Ni3' welds up to 5/16 in. (8.0 mm) maximum and groove welds made with a single pass or single pass each side '; *['7$*j,dNf,"gi,, ,,7g'**M"'j,*N"','"dM,-
may be made using an F7X EXXX clectrode-flux 0 35/0.s0 c s. 0.30/0.75; Ni. %. 0A0/0.80; Cr. %. 0As/0.70.
l combination. 2. owied . id metai shali have a minimam impaci sirength at charpy v.
Notch 20 ft Ib (27.1 J) at 0 'F (-18 'C)(only applied to t> ridges).
, 4.1.5.3 Gas Metal Arc Welding. Sm.gle pass fillet 3. uw or some type riller metal havins nest higher mechanical properties as welds up to 5/16 in. (8.0 mm) maximum and groove h ied in Aws .p.ciruiion i. permiited.
- n u a hat welds made with a single pass or single pass each side [,D',g'gd ,,'j
, ,"'f,*l,,sha1,1
,, j,a h, im may be made usmg an E70S-X electrode. proce 29
- - a ,, ., _ _ _ . . . _ . _ .
i e 30/ STRUCTURAL WELDING CODE Table 4.1.1-Matching filler metal requirementa )
STEEL SPECIFICATION REOUIRE MENTS FILLE R MET AL REQUIREMENTS Mesmes Teasde arength. g% Minimem Tensier strangik Steel Spenfication'* yiend peent range yasid point range kan M Pa km M Pa Specticatsoe u n, M r. kei M r.
ASTM AM' h 250 58-80 34 % 550 ASTM A33 Grade B 3S 240 00mm 413 ein ASTM Al06 Grade B 35 240 eo mee 415 sme WA*
ASTM A131 Grades A. B. C. CS, D. E $2 220 Ss 71 40 4 490
^*S ^3 8 A3 8 ASTM Al39 Grade 3 35 240 to min all mie Eem er MM 67 mm W 60 mm 413 mia E70X X $7 395 77 mm. Sin ASTM A381 Grade V35 $$ 240 ASTM A300 Grade A 33/39 230/270 43mm 310 mie SAw Grade S 42/46 290/320 Sa mm 400 min Au $ AS 17 er ASJ)
ASTM A501 h 250 55 mm 400 men F6X-EXXA or 50 343 62-80 429-550 ASTM ASi6 Grade SS 30 209 SF65 3s 4 490 F7X EXxx e0 415 7495 duk6SS Grade 60 32 220 e472 41 %493 mg ASTM A324 Grade i 35 240 ms3 415 Ss3 Aus AS 18 0'ade H M 20$ SSuo 3s 4 590 E705 A er e0 4t3 72 mes 494 ASTM AS?9 42 290 6485 41t495 EW.I 80 43 72 mm 493 ASTM AS10 Grade D 40 273 SS mm 380 mm Grade E 42 290 Sa mm 400 mia KAH ASTM AS'3 Grade 69 33 240 6%7' 430 330 AWS AS 20 ASTM A109 Grade 36' 36 230 58-80 14 % 550 Eh0T. A 90 14 % 62 mm 42%
API SL Grade B 33 240 00 413 E70T A ec 413 72 mm 495 Api SLAGrade 42 42 290 60 413 tEncepi -2 & 30 ABS Grades A. B. D. CS. DS Ss.71 ain490 Grade F* 58 73 antk490 ASTM AI.tl Grades AH32. DH32. EH32 43.5 313 64 59 4'0 Ss3 Grades AHM. DHM. EH% SI 350 71-90 49 4 620 ASTM A24? 42-50 294 345 6*-70mm 434-4s3 ASTM A441 42-50 29 4 345 okMatm 454330 ASTM AS16 Grade 63 39 240 6 S 77 454 930 Grade 70 38 2eo 1455 4s%3st SMAH ASTM AS37 Class 17 SO 343 7490 44 L620 A%5 AS I er AS S ASTM AS72 Grade 42 42 290 *0 min 40 mia EMXX 57 195 71 sim Sm Grade 43 43 310 60mm 413 mie Grade 30 50 343 H men 490 mee 54%
Grade SS SS 380 70 mm da.4 mm AH S AS 17 or 45.23 ASTM Atsr 14 is. and under) 30 345 10 mm an$ mm F7X-E X 1L X '* 43' 1" ***-**'
ASTM 4*95 brade A SS 350 63mm 450 mia nM4m Grade B sad C e0 413 70 mm eni min A%5 AS la AST 4 ANW 45 310 63mm 4% mre EMS. A or 60 414 72 mm 4**
ASTM A607 Grade 45 45 310 60 min 415 mis Eiot .i sa 4p 72 mis 4.
Grade 50 50 345 45 men 49u mie Grade SS SS 120 10 mm eat mm RA# l ASTM A61s 50 345 lu men esi ma AES AS 21s ASTM A633 Grade A. B- 42 290 63-8.1 43t3M E70T. A ec 4tt 12 men er*
Grade C. D 50 34 1 10 90 4Fb620 (Escept 2 & .30 (2-3 /2 sa. and madert AST M A109 Grade 50 SO 34% 65 mia 450 min brade 50% S0 34% M mm 4s3 mm API 204 42 290 62-h0 4 en.490 ABS Grades AH32. DH32. EH32 43.! 313 71-9U 56620 Grades AH4. DH%. EHM- 51 390 71-90 *en620 )
h4Am A%h A* 4 t uns. g 6* 4en *? mm de*
ASTM A"2 brade e ao 413 73 mie .* lS em Grade 64 65 450 no men 5% men A, , , g g,, q%
AST M AS.17 Oass ? 60 41' #4 500 35tkMu
- A5TM A63 Grade 5? 60 4') e4800 $40 690 , p 4,0 mi = 49n FCAW Grade E80T* 64 470 5493 594439 SMAn A%5 ASS E f 00X V' ST A0n 600 mia A90 ASTM S14 dever 2 l/2 m 163 me]) 90 420 105-133 723 930 hA*
a 02 p
- T* # ' **"
/2 to GMAw Grade EiffR en 100 mm 690
' FCAW Grade Elect
- ss 60$ 104 114 694790
$MAE AWS AS.S E now e A i10 mm M ASTM ASie (2-1/2 in. 100 690 libl)$ 79b930 fel mm) and undert han ASTM ASl7 100 690 libl35 79093U AWS AI23 FilX-E X X1r 98 679 114 110 7eae99 ASTM A10e Grades 100.100w 100 690 114130 7e4495 GMA*
(2 l/2 is.163 snel and ender) Grade El105* 98 679 l10 man Teo FCAW Grade Ell 0T* 98 475 814135 744th
- le comts 6 evolving base metais of too defierest yisid poemas er more than I en. (25 4 mm) thack for beidge ..
areepths,6teer mesel stuntedes opphsable te the leoer arength hear *$pecial weiding metanale and preouderes le.a E80X X les alley ele >
manni mey be usedressest that if the higher arength base metal re. tradest may be regered to match asect tougheene of base meal (for eseres leo byeregen eiereredes, thee shen be emed opphretions eswelving empest leedung er lee ensuperaseret er. for so. -3
'Melch API Standard 28 (fotricased setusi assesdens to seest used. mesphere corressen and weathenng chorestoratsse (see 4.5.4k
'W han welds are to be stres rehoved, the deposeed weld metal shall est leo hydrepte slesadications only, esamed 0 0S pre sent venedium. *Deseemed mete maal sheel he e a mimmem umancs arength of 3e R.
'See 420 for electregan and ensurening 14 nietal its (27.lJ3 as 0 *F (= lt *C6 when Charpy basssh specimens ase esad.
Vidy lee bydrogen elesundes absp be er* ' when weldes AM meal This regneresneat a appheshie eely to bndges.
i i . . ,. , . . _ _ _
Shielded setal Arc Welding l31 The ambient environmental temperature may be 4.6.2 in building construction, extension bars or run- l below 0 *F but a heated structure or shelter around , off plates need not be removed unless required by the i the area being welded could maintain the temperature Engineer, adjacent to the weldment at 0
- F or higher.) When the 4.6.3 In bridge construction, extension bars and run-base metal is below the specified minimum
, off plates shall be removed upon completion and cool-temperature, it shall be preheated so that the parts on
, ing of the weld, and the ends of the weld made smooth which weld metal is bung deposited are at or above and flush with the edges of the abutting parts.
the specified minimum temperature for a radius equal to the thickness of the part being welded, but not less than 3 in. (76.2 mm)in all directions from the point of welding. Preheat and interpass temperatures must be 4.7 Groove Weld Backing sufficient to prevent crack formation, and temperatures above the specified minimum may be 4.7.1 Groove welds made with the use of steel backing required for highly restrained welds. In joints in- shall have the weld metal thoroughly fused with the volving combinations of base metals, preheat shall be backing. On bridge structures, steel backing of welds as specified for the higher strength steel being welded. that are transverse to the direction of computed stress shall be removed and thejoint shall be finished smooth or ground. Steel backing of welds that are longitudinal 4.3 Heat Input Control for Quenched with the direction of stress or are not subject to com-Puted stress need not be removed, unless so specified and Tempered Steel by the Engmeer.
When quenched and tempered steels are welded, the 4.7.2 Steel backing of welds used in buildings or heat input shall be restricted in conjunction with the tubular structures need not be removed unless re-maximum preheat and interpass temperatures re- quired by the Engineer.
quired (by reason of base metal thicknesses). The 4.7.3 Steel backing shall be made continuous for the above limitations shall be in strict accordance with the full length of the weld. All necessary joints in the steel steel producer's recommendations. The use of stringer backing shall be completejoint penetration butt welds beads to avoid overheating is strongly recommended. meeting all workmanship requirements of Section 3 of Oxygen gouging of quenched and tempered steels is this code.
not permitted.
4.4 Arc Strikes 4.8 Caulking Arc strikes outside of the area of permanent welds Caulking of welds shall not be permitted.
should be avoided on any base metal. Cracks or blemishes caused by are strikes shall be ground to a smooth contour and checked to ensure soundness.
Part B 4.5 Weld Cleaning Shielded Metal Arc Welding Before welding over previously deposited metal, all slag shall be removed and the weld and adjacent base 4.9 Electrodes for Shielded Metal metal shall be brushed clean. This requirement shall Arc Welding apply not only to successive layers but also to successive beads and to the crater area when welding is 4.9.1 Electrodes for shielded metal arc welding shall resumed after any interruptior). It shall not, however, conform to the requirements of the latest edition of restrict the making of plug and slot welds in accor. AWS AS.I. Specification for Mild Steel Covered Arc dance with Appendix A. Welding Electrodes, or to the requirements of AWS AS.S. Specification for Low-Alloy Steel Covered Arc Welding Electrodes.
4.6 Groove Weld Termination 4.9.2 All electrodes having low hydrogen coverings .
conforming to AWS AS.1 shall be purchased in !
4.6.1 Groove welds shall be terminated at the ends of hermetically-scaled containers or shall be dried for at a joint in a manner that will ensure sound welds. least two hours between 450 *F (230 *C) and 500 *F Whenever possible, this shall be done by the use of ex. (260 *C) before they are used. Electrodes having low tension bars or run-off plates. hydrogen coverings conforming to AWS AS.5 shall be l l
7.- 1 iy 1
. - l l
! l 1
o . . . - -
i
,e ,
[
32/STRUCTURA1, WELDING CODE Table 4.2-Minimum preheat and interpeas temperature *
- I Thickness of Theckest Part at Pomt of M'"'"""
% eldm8 Temperature
! Steel Seccification p,,,,, %elding in. mm ASTM A36' ASTM A586 Grades 55 & 60 ASTM A53 Grade B ASTM A524 Grades 1 & ll ASTM A106 Grade B ASTM A529 Up to 3/4 19 incl. None' ASTM A135 Grades A. B ASTM A570 Graden D & E C.CS.D.E ASTM A!73 Grade 65 Shselded metal arc "" 3 #4 I' we!dmp mwh other thru l l/., 35 incl. 150 66 ASTM A139 Grade B ASTM A709 Grade 36-AST%8 A3sl Grade y35 than hm hydro en over 1 1/2 38 ASTM A500 Grade A rade 42 Grade B ABS Grades A. B. D. CS. DS ova bl/2 64 300 !$o ASTM A501 Grade E ASTM A36' ASTM A5'O Grades D & E ASTM A53 Grade B ASTM A572 Grades 42. 45 ASTM A106 Grade B $0, 33 ASTM A138 Grades A. B. C. ASTM A373 Grade 65 CS.D.E ASTM A$lix AH 32 & 36 ASTM A595 Grades A. B.
DH 32 & 36 c EH 32 & 36 ASTM A606 Upto 3/4 19inct w' ASTM A607 Grades 45. 50. Sheelded metal arc ASTM A139 Grade B
- Wing with 4o. over 3/4 19 35 ASTM A242 ASTM A618 hydrogen electrodes, thru l l/2 38 ind. 50 10 ASTM A388 Grade Y35 ASTM A633 Grades A. g submerged arc ASTM A441 over 3 1/2 38 Grades C. D
- Wing. pas meld arc thru 2 l/2 M mcl. 150 66 ASTM A500 Grade A ASTM A709 Grades 30. 50, 50g meldmg. flus cored arc Grade B API SL Grade B welding over 2-1/2 64 225 107 ASTM A501 ASTM A516 Grades 55 & 60 API SLX Grade 42 API Spec. 2H 65 & 70 ABS Grades AH 32 & 36 ASTM A524 Grade I & il DH 32 & 36 EH 32 & 36 .
ASTM A529 ABS Grades A. B. D.
ASTM A537 Classes I & 2 CS.DS Grade E Shicided metal arc O p to .814 19md su 10 melding unh is* mer 3 4 19
.i hsdrogen encorudes. Ihrul-l/2 in end Isn se.
4 ASTM A5?2 Grades 55.60.65 suhmerged arc ASTM A633 Grade E ecletup. pas metal arc melding. Gus iorcd ars Q' --,y meldmg over 21/2 f=4 Juu 150 Shielded metal arc ocidmp math loe Up to 3/4 19 incl. 50 10 ASTM A514 over 2-1/2 in. hydrogen electrodes. over 3/4 19 ASTM A517 submerged are weldmg thru l l/2 38 incl. 125 50 ASTM A709 Grades 100 & 100W wdh carhog or , , , , , , 33
,I,,'; ]',*s metal thru 2-1/2 M mcl 175 30 are meldmp or 11us over 21/2 N 225 110 cored are meldmg 00:03/4 19 incl. 50 10 ASTM A514 2-l/2 & under Suhmerged are "" ! "
ASTM A709 21/2 & under Grades 100 & 100W weldmp mith carbon . thru I-l/2 38 mcl. 200 95 steel mare. allow flua over 1 1/2 38 thru 2 l/2 ' 64 incl. Xio 150 over 2-1/2 64 400 205
'When the base metal temporalere is below 32 *F(0 *CL the base the menemum shone may be vegered for baghly restremed melds.
metal shau be preheated to at least 70 *t (28 *Cl and this nuesmem ter cuenched and tempered siert the masamum preheat and so-temperasure maseismed durmy welding serpow temperature shall est esceed 400 *F (209 *C) for thick -
Only goe.htdropen vissteedes shall be used when meldseg 43h steel semees up te 31/2 se (38 I mmt uscioneve. and 450 *F (230 *Cl for enore than I se. theck for bndges. prester thschasemen. Heat mput then acideng gesacked and '
'neideep shall een be done when the seeksene temperatore is leser tempered steel shall est esamed the stee6 prodseers
- than 0 *F l.18 *C) When the bene missal as betse the aseipere- seen. i tore hated for the weedseg preessa hang used sad the thschemes 'le poems sewolweg comhemations of bene metals, preheel shou be se 1 I of material beep welded, a shaR be preheseed teacept as other- sfuesfeed for the higher strength seest beseg maided. I I one provided) m such maener that the serisses of the ports se NOTL. Zero *> bis *Cp dans est mese ene enheent enewee- )
ohech meld metal as bases a -peed are at er above the essenhed mental temperasure but the temperature as the . vienuty I mammum esmperasure for a desanse semel to the thschemes of the of the estd The emperm _. al temperature may be helse I port euwig welded. bus met teen then 3 te. (7h mmk both leserauy and O *F. bue a hesied airectore er shelter areemd the area hang as advaast of the melding. Preheel end sneergoes semperatures meidad could -=== the temperastere adpseest le the esidenset meet be esfransas to prevent erset foranstem. Temperatere'shese se 0 *> er lugher.
s _.
Submerged Arc Welding /33 purchased in hermetically-scaled containers or shall 4.10.53 3/16 in. (4.8 mm) for subsequent layers of I be dried at least one hour at temperatures between 700 , welds made in the vertical, overhead and horizontal "F (370 *C) and 800 *F (430 *C) before being used. positions.
Electrodes shall be dried prior to use if the hermetically-scaled container shows evidence of 4.10.6 The maximum size fillet wel'd which may be damage. Immediately after the openmg of the made in one pass shall be:
hermetically-scaled container or removal of the elec- 4.10.6.I 3/8 in. (9.5 mm) in the Hat position.
trodes from drying ovens, electrodes shall be stored in 4.10.6.2 5/16 in. (8.0 mm) in horizontal or ovens held at a temperature of at least 250 *F (120 overhead positions, C). E70XX electrodes that are not used within four 4.10.63 1/2 in. (12.7 mm) in the vertical position.
hours. E80XX within two hours. E90XX within one 4.10.7 The progressions for all passes in vertical posi-hour, E100XX and E110XX within one-half hour tion welding shall be upwards except that undercut after the opening of the hermetically-scaled container may be repaired vertically downwards when preheat is or removal of the electrodes from a drying or storage in accordance with Table 4.2 but not lower than 70 'F oven shall be redried before use. Electrodes that have (21 'C). However, when tubular products are welded, been wet shall not be used. the progression of vertical welding may be upwards or 4.9.3 When requested by the Engineer, the contractor downwards but only in the direction or directions for or fabricator shall furnis'h an electrode manufacturer's which the weider is qualined.
certification that the electrode will meet the re- 4.10.8 Complete joint penetration groove welds made quirements of the classification. without the use of steel backing shall have the root gouged to sound metal before welding is started from 4.10 Procedures for Shielded Metal Arc Welding 4.10.1 The work shall be positioned for Dat position welding whenever practicable.
4.10.2 The classification and size of electrode, are length, voltage, and amperage shall be suited to the thickness of the material, type of groove, welding posi- Part C tions, and other circumstances attending the work.
Submerged Arc Wefding 4.10.3 The maximum diameter of electrodes shall be as follows:
4.10.3.1 5/16 in. (8.0 mm) for all welds made in the 4.11 General Requirements flat position, except root passes.
4.103.2 1/4 in. (6.4 mm) for horizontal fillet welds. 4.11.1 Submerged arc welding may be performed 4.103.3 1/4 in. (6.4 mm) for root passes of fillet w th one or more single electrodes, one or more parallel electrodes, or combinations of single and welds made in the Hat position and groove welds made m the flat position with backmg and with a root open- parallel electrodes. The spacing between arcs shall be ing of 1/4 in. or more" such that the slag cover over the weld metal produced by a leading are does not cool sufficiently to prevent 4.103.4 5/32 in. (4.0 mm) for welds made with the proper weld deposit of a following electrode.
l EXXI4 and low-hydrogen electrodes in the v'ertical Submerged are welding with multiple electrodes may and overhead positions. be used for any groove or fillet weld pass.
4.10.3.5 3/16 in. (4.8 mm) for root passes of groove welds and for all other welds not included under 4.11.2 The following paragraphs (4.11.3-4.11.8) 4.10.3.1. 4.103.2, 4.10.3.3 and 4.10.3.4 above. governing the use of submerged are welding are suitable for any steel included in 8.2,9.2, or 10.2 other 4.10.4 The minimum size of a root pass shall be suf- than those of the quenched and tempered group.
ficient to prevent cracking. Concerning the latter group, it is necessary to comply 4.10.5 The maximum thickness oflayers subsequent with the steel producer's recommendation for max.
to the root pass of fillet welds and of all layers of imum permissible heat input and preheat com-groove welds shall be: binations. Such considerations must includ,e the ad-4.10.5.1 1/4 in. (6.4 mm) for root passes of groove ditional heat input produced in simultaneous weldmg welds. n the two sides of a common member.
4.10.5.21/8 in. (3.2 mm) for subsequent layers of 4.11.3 The diameter of electrodes shall not exceed 1/4 welds made in the Dat position. in. (6.4 mm).
.- AWS D1.1-75
, , CASE EXHIBIT l,o % 2.
l Structural Welding Code Prepared by AWS Structural Welding Committee Under the Direction of AWS Technical Activities Committee Approved by AWS Board of Directors. June 16. 1975
\
AMERICAN WELDING SOCIETY, INC.
2501 N.W. 7th Street, Miami, Fla. 33125
Structural Welding Code
- 1. General Provisions 1.1 A PPli cation c red are welding (FCAW)procedureswhichconform to the provisions or Sections 2,3, and 4, in addition 1.1.1 This code covers welding requirements to Sections 8,9. or 10. as applicable, shall be deemed applicable to any type of welded structure, it is to be as prequalified and are therefore approved for used in con.iunction with any complementary code or use without performing procedure qualification tests.
specification for the design and construction of steel structures. It is not intended to apply to pressure 1.3.2 Electroslag (ESW) and electrogas' welding may vessels or pressure p,i ping. Requirements that are es- be used provided the procedures conform to the sentially common to all structures are covered in Sec- applicable provisions of Sections 2,3, and 4 and the tions I throuFh 7 while prov:sions applying exclusively contractor qualifies them in accordance with the re-to buildings (static loading), bridges (dynamic quirements of 5.2.
loading), or tubular structures are included in Sections 1.3.3 Stud wc! ding may be used provided the 8,9. and 10 respectively, procedures conform to the applicable provisions of 1.1.2 All references to the need for approval shall be 4.25 through 4.31.
interpreted to mean approval by the Building Com-missioner.' the Engineer,8 or the duly desiF nated re -
son acting for and in behalf of the owner on all matters I.4 Defin,il,ons l within the scope of this code. Hereinafter, the term The welding terms used in this code shall be inter.
Engineer will be used, and it is to be construed to preted in accordance with the definitions F iven in the mean the BuildinFCommissioner. the Engineer. or the duly designated person who acts for and in behalf of latest edition of AWS A3.0. Terms and Definitions supplemented bs Appendis I of this code.
the owner on all matters within the scope of this code.
- 1.5 Welding Symbols Il Base Metal w ,ig3 ,, ,y ,3 ,,, ,3 ,i, 3 , ,3 ,,, ,3 , ,, ; , in , i,,,,,
The base metals to be welded under this code are car- edition of AWS A2.4. Symbols for Welding and Non-bon and low alloy steels commonly used in ti c fabrica- destructive Testing. Special conditions shall be fully tion of steel structures. Steels complying with the explained by added notes or details, specifications listed in 8.2,9.2, and 10.2, together with special requirements applicable individually to each type of structure, are approved for use with this code.
Steels other than those listed in 8.2,9.2 and 10.2 may 1.6 Safety Precautions be used provided the provisions of 8.2.3, 9.2.4, or Safety precautions shall conform to the latest edition 10.2.3 are complied with. of ANS1 Z@l. Safety in Welding and Cutting, published by the American Welding Society.
1.3 Welding Processes 1.3.1 Shielded metal are welding (SMAW), sub- 1.7 Standard Units of Measurement merged are welding (SAW), gas metal are welding The values stated in U.S. customary units are to be (GMAW)(except short circuiting transfer), and flux regarded as the standard. The metric (SI) equivalents of U.S. customary units given in this code may be ap-
'The term Building Commissioner ** refers to the omcial or proximate, hurcau. by = hatever term locally destynated, who is delegated Io en-force the local building law or specifications or other construction regulations. ' The term electropas welding as used in this cmle refers to either gas 7he Engineer is the duty designated person who acts for sad in be- metal arc welding.clectropas (GM AW EGI or flus cored arc half of the owner on all matters within the scope of this codt. =ciding-electrogas (FCAW EG) or to both.
I
)
- 2. Design of Welded Connections Part A General Requirements 2.i.4 Detail drawings shall clearly indicate by welding, symbols or sketches the details of groove weldedjoints and the preparation of material required to make them. Both width and thickness of steel backing shall 2.1 Draw.ings 4 be detailed.
2.1.1 Full and complete information reFarding loca. 2.I.5 Any special inspection requirements shall be lion, type, size. and extent of all welds shall be clearly noted on the drawings or in the specifications.
shown e 1 the drawings. The drawings shall clearly dis.
tinguish between shop and field welds.
2.I.2 Drawings of those joints or groups of joints in 2.2 Basic Unit Stresses which it is especially important that the welding se-quence and technique be carefully controlled to Basic unit stresses for base metals and for effective minimite shrinkage stresses and distortion shall be areas of weld metal for application to buildings, so noted. bridges, and tubular structures shall be as shown in Part B of Sections 8,9. and 10 respectively.
2.1.3 Contract design drawings shall specify the effec-tive weld length and, for partial penetration groove welds, the required effective throat, as defined in 2.3 '
and 10.8. Shop or working drawings shall specify the 2.3 Effective Weld Areas, Lengths, groove depths (S) applicable for the effective throat and Throats (E) required for the welding process and position of welding to be used. 2.3.1 Grocte Welds. The effective area shall be the 2.1.3.1 It is recommended that contract design effective weld length multiplied by the effective throat.
drawings show complete joint penetration or partial .3.1.1 The effective weld length for any groove joint penetration Froove weld requirements as follows: weld, square or skewed, shall be the width of the part Joined. perpendicular to the direction of stress.
2.3.1.2 The effective throat of a complete joint
.. penetration groove weld shall be the thickness of the I p ne at on eld (CP) !
/ feinforcem nt 2.3.1.3 The minimum effective throat of a partial joint penetration groove weld shall be as specified in The welding symbol without dimensions designates a Table 2.10.3.
complete joint penetration weld.
2.3.2 Fillet Welds. The effective area shall be the effective weld length multipled by the effective throat (E,) , partial joint thickness. Stress in a fillet weld shall be considered as
/ (E,) x penetration weld applied to this effective area, for any direction of applied load.
2.3.2.1 The effective length of a fillet weld shall be Where, the overall length of the full-size fillet, including end E, = cfrective throat. other side '*l"fns. No reduction in efrective length shall be made for either the start or crater of the weld if the weld is E. = cffective throat, arrow side full size throughout its length.
Special groove details shall be specified where re. 2.3.2.2 The effective length of a curved fillet weld quired, shall be measured along the center line of the effective ,
throat. If the weld area of a fillet weld in a hole or slot computed from this length is greater than the area
'TN icrm -drawings" refers to plans. design and detail drawmss. found from 2.3.3, then this latter area shall be used as
""d"'"'""'"*-
the effective area of the fillet weld.
2
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Details of WeldedJointsl3 2.3.2.3 The minimum effective length weld shall be at least four times themal nom,size,ofora fillet Part C Details of Welded Joints the size of the weld shall be considered not to exceed one fourth its effective length. 2.6 Joint Qualification I 2.3.2.4 The effective throat shall be the shortest dis-tance from the root to the face of the diagrammatic 2.6.1 Joints meeting the following requirements are weld. designated as prequalified:
(1) Conformance with the details specified in 2.9 233 Plug and Slot Welds. The effective area, shall be through 2.14 and in 10.13.
the nominal area of the hole or slot in the plane of the (2) Use of one of the following welding processesin faying surface. accordance with the requirements of Sections 3. 4, and 23.4 The effective throat of a combination partial 10 as applicable: shielded metal arc, submerged arc, i joint penetration groove weld and a fillet weld shall be gas metal arc (except short circuiting transfer) or flux l I
the shortest distance from the root to the face of the cored are welding.
diagrammatic weld minus 1/8 in. (3.2 mm) for any Joints meeting these requirements may be used with-groove detail requiring such deduction (See Appendix out performing the joint welding procedure qualifica.
B). tion tests prescribed in 5.2.
2.6.1.1 The joint welding pro'cedure for all joints welded by short circuiting transfer gas metal are weld-ing (see Appendix D) shall be qualified by tests pre-scribcd in 5 2-Part B Structural Details 2.4 Fillers 2.4.1 Fillers may be used in: #__'
o
" " " ' " ~ '_'
2.4.1.1 Splicing parts of different thicknesses.
2.4.1.2 Connections that. due to existing geometric N alignment, must accommodate off-sets to permit sim- - N ple framing. % 9_r 2.4.2 A filler less than I/4 in. (6.4 mm) thick shall not tran=ree M* 'Ib '
q be used to transfer stress but shall be kept flush with *****'F the welded edges of the stress carrying part. The sizes bgp I
" " ' ' ^
I mono = =
of welds along such edges shall be increased over the .1. .
required sizes by an amount equal to the thickness of E"***" **' L - '
the filler (see Fig. 2.4.2). @,,re Effectwo area of weld 2 snail equal inat of weld 1 but ets size 2.43 Any filler I/4 in. (6.4 mm) or more in thickness snan be n enect are neus = in.cnn.n e m emwa shall extend beyond the edges of the splice plate or Fig. 2.4.2-Fillers less than 1/4 in. thick.
connection material. It shall be welded to the part on which it is fitted and the joint shall be of sufficient strength to transmit the splice plate or connection ,c, ,2=m~ ,
d b material stress applied at the surface of the filler as an d eccentric load. The welds joining the splice plate or --
connection material to the filler shall be sufficient to -
~~'
r 4-, r, p',,, _= e_2.w ~ q~
transmit the splice plate or connection material stress ,
9 and shall be long enough to avoid overstressing the filler along the toe of the weld (see Fig. 2.4.3). Tr n = ree.,
wetos may 3 2 1 i
be used l siong inese "
' '~ "
2.5 Partial Joint Penetration Groove eaa= m <
Welds '
Partial joint penetration groove welds subject to letectwo area of wed 2 enan eous inei es weid 1. Tne ionsin ce weid tension normal to their longitudinal axis shall not be 2 en.n es autacienno.wwt owr ==mno m anson enar mono mena used where design criteria indicate cyclic loading Effectrue area of weld 3 snell et least equalinat of weld 1 and tnere could produce fatigue failure. Joints containing such 7c'","*,,",n*,7,,g,M*,,d "ad a raunine from = -
welds, made from one side only. shall be restrained to prevent rotation. Fig. 2.43-Fillers 1/4 in. or thicker. ;
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l 4/ STRUCTURAL WELDING CODE 2.6.2 Joint details may depart from the details 1/ts prescribed in 2.9 through 2.14 and in 10.13 only if the 1 l contractor submits to the Engineer his proposedjoints and joint welding procedures and at his own expense t ( f N demonstrates their adequacy in accordance with the 4 }
aase m tai ess
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1 requirements of 5.2 of this code and their confor- Base metai 1 a
,, g, ,n , ,n g mance with applicable provisions of Sections 3 and 4. '
A B Maximum size of 880et weld along edges 1 2.7 Details of Fillet Welds 2.7.1 The details of fillet welds made by shielded ,j ,
metal arc, submerged arc, gas metal are or flux cored #
im e, 0,,
are welding to be used withoutjoint welding procedure ej .g, ,
qualification are listed in 2.7.1.1 through 2.7.1.5 and > , ,, -
detailed in Figs. 2.7.1 and 10.13.1.3. "N _E d _l L-2.7.1.1 The minimum fillet weld size. except for yI y k fillet welds used to reinforce groove welds, shall be as c -
O shown in the following table: skewed T.loints All dimensions m inches.
Fig. 2.7.1-Details forfillet welds.
Base Metal Thickness of Minimum Site Thicker Part, Joined (T) of Fillet Weld
- M' Plug and Slot Welds 5 in. mm in. mm 2.8.1 Plug and slot welds in lapjoints may be used to transmit shear or to prevent the buckling or separa-tion of lapped parts. j T<l/4 T(6.4 I/8" 3 I/4 <T(1/2 6.4 < T ( 12.7 3/16 5 single pass 2.8.2 The diameter of the hole for a plug weld shall be 1/2 < T(3/4 12.7 < T (19.0 1/4 6 welds must no less than the thickness of the part containing it 3/4 < T 19.0 < T 5/16 8 be used plus 5/16 in. (8.0 mm) preferably rounded to the next greater odd I/16 in. (1.6 mm). The diameter of the Except that the weld site need nat escced the thickness of the hole for a plug weld shall not be greater than 21/4 thinner part joined. For this exception particular care should be times the thickness of the weld, t.iken to provide sufficient preheat to ensure weld soundness.
Minimum size for bridge appneation 3/16 in. 2.8.3 The minimum center to center spacing of plug welds shall be four times the diameter of the hole.
2.8.4 The length of the slot for a slot weld shall not 2.7.1.2 The maximum fillet weld size permitted exceed ten times the thickness of the weld.The width along edges of material shall be: of the slot shall be no less than the thickness of the (I) The thickness of the base taetal, for metalless Part containing it plus 5/16 in. (8.0 mm) preferably than I/4 in. (6.4 mm) thick (see Fig. 2.7.1, detail A). rounded to the next greater odd I/16 in. (1.6 mm) nor (2) 1/16 in. (1.6 mm) less than the thickness of base shall it be greater than 2-1/4 times the thickness of the metal, for metal I/4 in. (6.4 mm) or more in thick- weld.
ness (see Fig. 2.7.1, detail B), unless the weld is desig- 2.8.5 . Plug and slot welds are not permitted in nated on the drawing to be built out to obtain full quenched and tempered steels.
throat thickness.
2.7.l.3 Fillet welds in holes, or stats in lap joints, 2.8.6 The ends of the slot shall be semicircular or -
may be used to transfer shear or to prevent buckling shall have the corners rounded to a radius not less than or separation oflapped parts. These fillet welds may the thickness of the part containing it, except those overlap, subject to the provisions of 2.3.2.2. Fillet ends which extend to the edge of the part.
welds in holes or slots are not to be considered as plug 2.8.7 The minimum spacing oflines of slot welds in a or slot welds, direction transverse to their length shall be four times 2.7.1.4 Fillet welds may be used in skew joints that the width of the slot. The minimum center to center have an included angle of not less than 60 degrees. spacing in a longitudinal direction on any line shall be (See Fig. 2.7.1, details C and D). two times the length of the slot.
2.7.l.5 The minimum length of an intermittent fillet weld shall be 1-1/2 in. (38.1 mm). see Appendis A for the technique of making plug and slot welds.
.J
Details of Welded Joints l5 2.8.8 The thickness of plug or slot welds in metal S/8 2.10 Partial Joint Penetration Groove in. (15.9 mm) thick or less shall be equal to the thick .
ness of the material. In metal over S/8 in. thick, it Welds Made b7 Shielded Metal shall be at least one-half the thickness of the material Arc Welding but no less than 5/8 in.
2.10.1 Except as provided in 10.13.1.1, groove welds without steel backing, welded from one side, and groove welds welded from both sides but without back 2.9 Complete Jo.mt Penetrat. ion sousins are considered partial joint penetratior Groove Welds Made by Shielded groove welds. Partial joint penetration groove welds Metag Arc Welding made b,y shielded metal are welding in butt, T, and corner jomts which may be used without performing 2.9.1 Complete joint penetration groove welds made the joint welding procedure qualification tests pre-
. senbed in 5.2 are detailed in Fig. 2.10.1 and are sub-by shielded metal arc weldm.g m butt, T ,and corner ject to limitations specified in 2.10.2 joints which may be used without performing thejomt welding procedure qualification tests prescribed in 2.10.2 Dimensions of groove welds specified on design 5.2 are detailed in Fig. 2.9.1 and are subject to the or detail drawings may vary from the dimensions the limitations specified in 2.9.2. shown in Fig. 2.10.1 only within the following limits:
2.9.2 Dimensions of groove welds specified on design 2.10.2.1 The groove angle is minimum. It may be or detail drawings may vary from the dimensions detailed to exceed the, dimension shown by no more shown in Fig. 2.9.1 only within the following limits: than ten degrees. , ,
2.9.2.1 The specified thickness of base metalis the . 2.10.2.2 The radius of the U-grooves and J-grooves I
maximum nominal thickness that may be used. is mmimum. It may be detailed to exceed the dimen-2.9.2.2 The root face of thejoints shall be as dimen- sion sho'vn by no more than I/8 m. (3.2 mm). -
sioned in Fig. 2.9.1. It may be detailed to exceed the gr oves may be prepared before or after fittmg.
specified dimension by no more than 1/16 in. (1.6 2.10.2.3 Double-groove welds may have grooves of, mm). It may not be detailed less than the specified Unequal depth, provided that the weld deposit on each dimension. side of the joint conforms to the limitations of Fig. '
2.9.2.3 The root opening of the joints is minimum. 2.10.1.
l It may be detailed to exceed the dimension shown by 2.10.3 The effective throat of partialjoint penetration i no more than 1/16 in. (1.6 mm). square . bevel , and V-groove welds shall be as shown 2.9.2.4 The groove angle is minimum. It may be in Table 2.10.3.
detailed to exceed the dimension shown by no more 2.10.3.1 Shop or working drawings shall specify the than ten degrees. groove depths (S) applicable for the effective throat 2.9.2.5 The radius of J-grooves and U grooves is (E) required for the welding process and position of minimum. It may be detailed to exceed the dimension wc! ding to be used.
shown by no more than 1/8 ine(3.2 mm). U-grooves may be prepared before or after fitting. 2.10.4 The minimum root face of the joints shall be 2.9.2.6 Double-groove welds may have grooves of 1/8 in. (3.2 mm).
unequal depth, but the depth of the shallower groove 2.10.5 For corner joints, the outside groove prepara-shall be no less than one. fourth of the thickness of the tion may be in either or both members, provided the thinner part joined. basic groove configuration is not changed and ade-2.9.3 For corner joints. the outside groove preparation qu te edge distance is maintained to support the may be in either or both members, provided the basic welding operations without excessive edge melting.
groove configuration is not changed and adequate edge distance is maintained to support the welding operations without excessive edge melting.
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6/ STRUCTURAL WELDING CODE 1
Table 2.10.3-Minimum effective throat for Legend for Figs. 2.9.1 through 2.14.1 )
partial joint penetration groove welds Symbols for joint types Base metal thickness of Minimum efrective B - butt joint thicker partjoined, throat C - corner joint in. (mm) in. mm T - T joint ;
BC - butt or corner joint '
to 1/4 (3.2) incl. 1/8* 3 TC - T or corner joint i over I/4 (3.2) to 1/2 (12.7) incl. 3/16 5 BTC - butt. T. or corner joint over I/2 (12.7) to 3/4 (19.0) incl. I/4 6 l over 3/4*(19.0) to I-l/2 (38.1) incl.
4 5/16 8 Symbols for base metal thickness and penetration over 1-l/2 (38.1) to 2-1/4 (57.1) incl. 3/8 10 over 2-1/4 (57.1) to 6 (152) incl. 1/2 13 L-limited thickness-complete joint over 6 (152) enetration 5/8 16 U-unhmited thickness-complete joint a
- Mimmum sue for bridge applicanons 3/16 in.
[
Symbols for weld types Metric (SI) Equitslents 1 - square-groove for Section 2 Figures 2 - single-V-groove 3 - double-V-groove in. mm in. mm 4 - single-bevel-groove 1/32 0.8 2 50.8 5 - double-bevel-groove 1/16 1.6 2-1/8 54.0 6 - single-U-groove 1/8 3.2 2-3/8 60.3 7 - double-U-groove 3/16 4.8 2-1/2 63.6 8 - single-J-groove 1/4 6.4 2-3/4 70.0 9 - double-J-groove 3/8 9.5 3 76.2 3 5/8 15.9 3-l/4 82.6 Symbol for welding processes, if not shielded '
1/2 12.7 3-5/8 92.1 metai arc 3/4 19.0 3-3/4 95.2 S - submerged arc welding I' 25.4 4 102 G - gas metal are welding I-3/8 34.9 4-3/4 121 F - flux cored arc welding I-l/2 38.1 5-l/2 I40 1-3/4 44.5 6-l/4 159 1
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Workmanship /27 3*7 Corrections 3.7.6 Ir, arter an unacceptable weld has been made,
, work is performed which has rendered that weld in-accessible, or has created new conditions that make correction of the unacceptable weld dangerous orin-3.7.1 The removal of weld metal or portions of the effectual, then the original conditions shall be restored base metal may be done by machining, grinding, chip- by removing welds or members or both before the cor-ping, oxygen gouging, or air carbon are gouging. It rections are made. If this is not done, the deficiency shall be done in such a manner that the remaining shall be compensated for by additional work per-weld metal or base metal is not nicked or undercut. formed according to an approved revised design.
Oxygen gouginF shall not be used in quenched and tempered steel. Unacceptable portions of the weld 3.8 Peening shall be removed without substantial removal of the base metal. Additional weld metal to compensate for Peening may be used on intermediate weld layers for any deficiency in size shall be deposited using an elec- control of shrinkage stresses in thick welds to prevent trode preferably smaller than that used for making the cracking. No peening shall be done on the root or sur-original weld. and preferably not more than 5/32 in. face layer of the weld or in the base metal at the edges (4.0 mm) in diameter. The surfaces shall be cleaned of the weld. Care should be taken to prevent overlap-thoroughly before welding. ping or cracking of the weld or base metal.
3.7.2 The contractor has the option of either repairing an unacceptable weld, or removing and replacing the 3.9 Stress Relief Heat Treatrnent'2 entire weld, except as modified by 3.7.4. The repaired or replaced weld shall be retested by the method 3.9.1 Where required by the contract drawings or originally used, and the same technique and quality specifications, welded assemblies shall be stress re-acceptance criteria shall be applied. If the contractor lieved by heat treating. Finish machining shall pre-elects to repair the weld, it shall be corrected as ferably be done after stress reliaving.
follows: 3.9.1.1 The stress relief treatment shall conform to 3.7.2.1 Overlap or Excessive Convexity. Remove the following requirements:
excess weld metal. (1) The temperature of the furnace shall not exceed 3.7.2.2 Excessive Concavity of Weld or Crater, 600 *F,(315 *C) at the time the welded assembly is Undersize Welds. Undercutting. Prepare surfaces (see placed in it.
4.5) and deposit additional weld metal. (2) Above 600 *F (315 *C). the rate of heating" 3.7.2.3 Excessive Weld Porosity, Excessive Slag shall not be more than 400 *F (220 *C) per hour inclusions. Incomplete Fusion. Remove unacceptable divided by the maximum metal thickness of the portions (see 3.7.1) and reweld, thicker part in inches. but in no case more than 400 'F 3.7.2.4 Cracks in Weld or Base Metal. Ascertain the per hour. During the heating period, variation in extent of the crack by use of acid etching, magnetic temperature throughout the portion of the part being particle inspection, or other equally positive means; heated shall be no greater than 250 'F (I40 *C) within remove the crack and sound metal 2 in. (50.8 mm) any 15 ft (4.6 m) interval of length.
beyond each end of the crack, and reweld. (3) After a maximum temperature of 1100 *F 3.7.3 Members distorted by welding shall be (590 *C)is reached on quenched and tempered steel, or a mean temperature range between 1100 'F and straightened by mechamcal means or by carefully su-pervised application of a hmited amount oflocalized 1200 *F (650 *C) is reached on other steels, the heat. The temperature of heated areas as measured temperature of the assembly shall be held within the by approved methods shall not exceed 1100*F(590*C) specified limits for one hour per inch of weld for quenched and tempered steel nor 1200*F (650*C)
(a dull red color) for other steels. The part to be " Stress relieving of weldments of quenched and tempered steelis
)
heated for straightening shall be substantially free of not generally required. stress relieving may be necessary for those ,
stress and from external forces, execPt those stresses
- PP**'i "" *h* **Id**" *" '***I" di"*"'i nal stability dur.
ing machining or where stress corrosion may be m.volved. neither resulting from the mechanical straightening method condition being unique to weldments of quenched and tempered used in conjunction with the application of heat. steel. However, the results of notch toughness tests have shown that postweld heat treatment may actually impair weld metal and heat. l 3.7.4 Approval shall be obtained for such corrections arfected zone toughness and intergranular cracking may sometimes I as: repairs to base metal (other than those required by occur in the grain. coarsened re8 ion of the weld heat.affected zone.
{
3.2), repair of major or delayed cracks, or for a revised design to compensate for deficiencies. ,, The rates of heating and cooling need not be less than 100 'F ($$
(
- C) per hour. However in all cases, consideration of closed cham. l t } . bers and complex structures may indicate reduced rates of heating l
3.7.5 The Engineer shall be notified before improper- and cooling to avoid structural damage due to excessive thermal l ly fitted and welded members are cut apart. gradients.
1
,s .
Submerged Arc Welding /33 purchased in hermetically scaled containers or shall 4.10.53 3/16 in. (4.8 mm) for subsequent layers of be dried at least one hour at temperatures between 700 , welds made in the vertical, overhead and horizontal
- F (370 *C) and 800 *F (430 *C) before being used. positions.
Electrodes shall be dried prior to use if the hermetically-scaled container shows evidence of 4.10.6 The maximum size fillet wefd which may be damage. Immediately after the openmg of the made in one pass shall be:
hermetically scaled container or removal of the elec- 4.10.6.1 3/8 in. (9.5 mm) in the flat position, trodes from drymg ovens, electrodes shall be stored in 4.10.6.2 5/16 in. (8.0 mm) in horizontal or ovens held at a temperature of at least 250 *F (120 overhead positions.
- C). E70XX clectrodes that are not used within four 4.10.63 1/2 in. (12.7 mm) in the vertical position.
hours, E80XX within two hours. E90XX within one 4.10.7 The progressions for all passes in vertical posi-hour, E100XX and E110XX within one-half hour tion welding shall be upwards except that undercut after the opening of the hermetically scaled container may be repaired vertically downwards when preheat is or removal of the electrodes from a drying or storage in accordance with Table 4.2 but not lower than 70 'F oven shall be redried before use. Electrodes that have (21 *C). However, when tubular products are welded, been wet shall not be used. the progression of vertical welding may be upwards or 4.93 When requested by the Engineer. the contractor downwards but only in the direction or directions for or fabricator shall furnis'h an electrode manufacturer's which the welder is qualified.
certification that the electrode will meet the re- 4.10.8 Completejoint penetration groove welds made quirements of the classification, without the use of steel backing shall have the root gouged to sound metal before welding is started from 4.10 Procedures for Shielded Metal Arc Welding 4.10.1 The work shall be positioned for flat position welding whenever practicable.
4.10.2 The classification and size of electrode, are length, voltage, and amperage shall be suited to the thickness of the material, type of groove, welding posi-gg tions, and other circumstances attending the work.
Submerged Arc welding 4.103 The maximum diameter of electrodes shall be as follows:
4.10.3.1 5/16 in. (8.0 mm) for all welds made in the 4.11 General Requirements flat position. except root passes.
4.103.2 1/4 m. (6.4 mm) for horizontal fillet welds. 4.11.1 Submerged arc welding may be performed 4.10.3.3 1/4 in. (6.4 mm) for root passes of fillet w th one or more single electrodes, one or more parallel electrodes, or combinations of single and i
welds made in,the flat pos,tio,n and groove welds made in the flat position with backing and with a root open-parallel electrodes. The spacing between arcs shall be mg of 1/4 in. or more, such that the slag cover over the weld metal produced by a leading are does not cool sufficiently to prevent 4.103.4 5/32 in. (4.0 mm) for weids made with the proper weld deposit of a following electrode.
EXXI4 and low-hydrogen electrodes in the vertical SubmerFed arc welding with multiple electrodes may and overhead positions. be used for any groove or fillet weld pass.
4.10.3.5 3/16 in. (4.8 mm) for root passes of groove welds and for all other welds not included under 4.11.2 The following paragraphs (4.11.3-4.11.8) 4.103.1. 4.103.2. 4.10.3.3 and 4.10.3.4 above. governing the use of submerged arc welding are suitable for any steel included in 8.2,9.2, or 10.2 other 4.10.4 The minimum size of a root pass shall be suf- than those of the quenched and tempered group.
ficient to prevent cracking. Concerning the latter group, it is necessary to comply 4.10.5 The maximum thickness oflayers subsequent with the steel producer's recommendation for max-to the root pass of fillet welds and of all layers of imum permissible heat input and , preheat com-groove welds shall be: binations. Such considerations must melud,e the ad-4.10.5.1 1/4 in. (6.4 mm) for root passes of groove ditional heat,mput produced in simultaneous welding weldt n the two sides of a common member.
4.10.5.21/8 in. (3.2 mm) for subsequent layers of welds made in the flat position. 4.113 The diameter of electrodes shall not exceed 1/4 in. (6.4 mm).
.* a, t 3
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46/ STRUCTURAL. WELDING CODE cepted. For example, a procedure qualified with a 1 in. (d) The omission, bm not inclusion, of backing (25.4 mm) thick 100 000 psi (690 MPa) yield strength material.
base metal also' qualifies for a 3 in, (76.2 mm) thick (9) A decrease of more than 25 *F(13.9 *C)in the 90 000 psi (620 MPa) yield strength base metal of the minimum specified creheat or interpass temperature.
same material specification. (10) In veni:al welding, a change in the progres-5.5.1.4 Qualification of a welding procedure es- sion specified for any pass from upward to downward tablished with a combination of base metals included or vice versa.
in 10.2 ofdifferent minimum specified yield strengths, 5.5.2.2 Submerged Are Welding one of which is greater than 50 000 psi (345 MPa) (1) A change in electrode and flux combination shall qualify the procedure for welding that high yield not covered by AWS A5.17 or AS.23.
strength base metal to any other of those base metals (2) A change increasing filler metal strength level having a minimum specified yield strength equal to or (from Grade F80 to Grade F90, for example, but not less than that of the lower strength base metal used in vice versa).
the test. (3) A change in electrode diameter when using an 5.5.1.5 in preparing the procedure specification the alloy flux.'*
manufacturer or contractor shall report the specific (4) A change in the number of electrodes used.
values for the essential variables that are specified in (5) A change in the type of current (ac or dc) or 5.5. The suggested form for showing the information polarity when welding quenched and tempered steel or required in the procedure specification is given in Ap. when using an alloy flux.
pendix E. (6) A change of more than 10 percent above or below the specified mean amperage for each electrode 5.5.2 The changes set forth in 5.5.2.1 through 5.5.2.5 diameter used."
shall be considered essential changes in a welding (7) A change of more than 7 percent above or be-procedure and shall require establishing a new low the specified mean are voltaFe for each diameter procedure by qur.lification. When a combination of electrode used.
welding processes is used, the variables applicable to each process shall apply. (8) A chanFe of more than 15 percent above or
. below the specified mean travel speed."
5.5.2.1 Shielded Metal Arc Welding (9) A change of more than 10 percent or 1/8 in.
(1) A change increasing filler metal strength level (3.2 mm), whichever is greater, in the longitudinal (a change from E70XX to E80XX, for example, but spacing of the arcs.
not vice versa). (10) A change of more than 10 percent, or 1 (2) A change from a low hydrogen type electrode in. (1.6 mm) whichever is greater, in theac-lateral sp/16 to a non. low hydrogen type of electr* ode, but not vice ing of the arcs.
versa.
(II) A change of more than
- 10 deg in the (3) An increase in the diameter of the electrode us- angular position of any parallel electrode.
ed, over that called for in the procedure specification. (12) A change in the angle of electrodes in (4) A change of more than 15 percent above or machine or automatic welding of more than:
below the specified mean are voltage and amperage (a)
- 3 deg in the direction of travel.
for each size electrode used.
(b)
- 5 des normal to the direction of travel.
(5) For a specified groove, a change of more than (13) For a specified groove, a change of more than
- 25 percent in the specified number of passes.1f the , i 25 percent in the specified number of passes. If the area of the groove is increased,it is also permissible to area of the groove is increased, it is also permissible to increase the number of passes in proportion to the in- increase the number of passes in proportion to the in-creased area-creased area.
(6) A change in position in which welding is done (14) A change in position in which welding is done as defined in 5.8.
as defined in 5.8.
(7) A change in the type of groove (a change from -
a b, to a U groove, for example). (15) A change in the type of groove (a change (8) A change exceeding tolerances of 2.9. 2.10, or from a W to a U. groove, for example).
10.13 in the shape of any one type of groove in-(16) A change, exceeding tolerances of 2.11,2.12, volving:
(a) A decrease in the included angle of the groove, (b) A decrease in the root opening of the groove,
,.The temperature may fall more than 25 'F below the minimum (c) An increase in the root face of the groove, specined, provided: (1) the provisions of 3.43 and Table 4.2 m complied with, and (21 the work shall be at the spacined minimum temperature at the time of subsequent welding.
"When welding quenched and tempered steel, any change within the limitation of variables shall not increase the heat input beyond the "An alloy Aus is defined as a Aus upon which the alloy content of steel producer's recommendations. the weld metal is largely dependent
I Structural Details l81 8.2.3 When a steel other than those listed in E.2.1 is sponding increase shall be applied to the allowable approved under the provisions of the general building unit etress for welds.
code and such steel is proposed for welded construc-tion, the weldability of the steel and the procedure for wc! ding it shall be established by qualification in ac-cordance with requirements of 5.2 and such other re-quirements as prescribed by the Engineer.
8.2.3.1 The responsibility for determining weldabil-ity. including the assumption of the additional testing Part C cost involved, is assigned to the party who either specines a material other than listed in 8.2.1 or who StructNral Oetails proposes the use of a substitute material not listed in 8.2.1. The fabricator shall 'inve the responsibility of establishing the welding procedure by qualification.
8.2.4 Extension bars, run.off plates, and backing used 8.6 Combinations of Welds in welding shall conform to the following re-If two or more of the Feneral types of welds (groove, he used in welding with an approved steel et, plug, sloO are comMned in a single @t. We listed in 8.2.1,it may' be any of the steels listed in 8.2.1, all wable capacity of each shall be separately com-(2) When used its welding with a' steel qualified in puted with reference to the axis of the group, m order accordance with 8.2.3 it may be:
(a) The steel qualified, or b nat n*
(b) Any steel listed in 8.2.1.
Spacers used shall be of the same material as the 8.7 Welds in Combination with Rivets base metal.
and Bolts 8.2.5 The provisions of this code are not intended for use with steels having a minimum specified yield point Rivets or bolts used in bearing. type connections shall or yield strength over 100 000 ps,i (690 MPa).
not be considered as sharing the stress in combination with welds. Welds, if used, shall be provided to carry the entire stress in the connection. However, connec.
tions that are welded to one member and riveted or bolted to the other member are permitted. High Part B strength bolts properly installed as a friction. type con.
nection prior to welding may be considered as sharing Allowable Unit Stresses the stress with the welds.
8.3 Base Metal Stresses The base metal stresses shall be those specified in the 8.8.1 If I neitudinal fillet welds are used alone in end applicable Building Code, connections of Dat bar tension members, the length of each fillet weld shall be no less than the perpendicular distance between them. The transverse spacing of 8.4 Unit Stresses in Welds i ngitudinal GHet welds used in end c nnecti ns shall not exceed 8 in. (203 mm), unless end transverse welds 8.4.1 Except as modified by 8.5, allowable unit stress r intermediate plug or slot welds are used.
in welds shall not exceed those listed in Table 8.4.1. 8.8.2 Intermittent fillet welds may be used to carry 8.4.2 Stress on the effective throat of Gilet welds is calculated stress.
considered as shear stress regardless of the direction of 8.8.3 For lap joints the minimum amount oflap shall application. I be five times the thickness of the thinner part joined 1 I
, but not less than I in. (25.4 mm) (see Fig. 8.8.3).
8.5 increased Unit Stresses 8.8.41 ap joints in parts carrying axial stress shall be double. fillet welded (see Fig. 8.8.3), except where de-Where the lluilding Code permits the use ofincreased Acetion of the joint is sufficiently restrained to pre.
unit stresses in the base metal for any reason, a corre. vent it from opening under load.
l 88/ STRUCTURAL WELDING CODE i
Table 8.4.1-Allowable stresses in welds I
Wefd Stress in weld' Allowable stress 4" ftren 1 Tension normal to the effec- Matching weld metal must be tive area See as base W used. See Table 4.1.1
.E Weld metal with a strength E Compression normal to the I*I . equal to or one clas.
55 gg effective area Same as base metal sificatmn (10 ksi) less 8 than matching wc!d metal
.E 9 may be used
.2, g T ension or compression gg parallel to the axis of the weld Same as base metal Weld metal with a strenFth level equal to or less than
- 7. 0.3O nominal tensile strength E matching weld meul may be of weld metal (ksi), except used 0 Shear on the effective area shear stress on base metal shall not exceed 0.40 yield stress of base metal Compression Joint not 0.50 nominal tensile strength of normal to designed to weld metal (ksi) cacept stress effective area bear on base metal shall not exceed 0.60 yield stress of base metal Joi designed Same as base metal S
E* Tension or compression E3 parallel to the axis of the weld' Same as base metal Weld metal with a strength E8 level equal to or less than
.E Y matching weld metal may be A8 0.30 nominal tensile strength used of weld metal fksi), except 3E Shear parallel to axis of weld shear stress on base metal shall 5 not exceed 0.40 yield stress c.-
of base metal 0.30 nominal tensile strength Tension normal to effective of weld metal (ksi), except area shear stress on base metal shall not exceed 0.60 yield stress of base metal 0.30 nominal tensile strength of weld metal (ksi). except ha Shear ori effective area shear stress on base metal shall Weld metal with a strength not exceed 0.40 yield stress level equal to or less 3 of base metal than matching metal may be g used Tension or compression parallel to axis of weld Same as base metal 0.30 nominal tensile strength a, Shear parallel to faying of weld metal (ksi), except Weld metal with a strength
? surfaces (on effective area) shear stress on base metal shall level equal to or less than itj not exceed 0.40 yield stress matching metal may be used of base metal
'For definition of effective area, see 2.3.
8For matching weld metal, see Table 4.1.1.
' Fillet welds and partialjoint penetration groove weldsjoining the component elements og Silt.
up members, such as flange-to-web connections, may be designed without regard to the teneile or compressive stress in these elements parallel to the amis of the welds.
o Structural Details /89
't interrupt weld at corner b '
d l' i. I/ y
' /// /// // /////// //
7*.7.2 * .J Fig. 8.8.3-Double-fillet-welded lap joint. )')
h j 8.8.5 Fillet welds deposited on the opposite sides of a
,')
6 common plane of contact between two parts shall be interrupted at the corner common to both welds. (See ,A t!
Fig. 8.8.5). ,j t!
gg 8.8.6 Boxing (End Returns) p-8.8.6.1 Side or end fillet welds terminating at ends /)
p' or sides, respectively, of parts or members shall, ,j g.
wherever practicable, be returned continuously 9 y around the corners for a distance at least twice the nominal size of the weld except as provided in 8.8.5.
This provision shall apply to side and top fillet welds h connecting brackets, beam seats and similar connec-tions on the plane about whicli bending rr.oments are computed. h 8.8.6.2 End returns shall be indicated on the draw. Fig. 8.8.3-Filler welds on opposite sides of a com-ings. mon plane.
8.9 Eccentricity 8.12 Connections of Components of in general adequate provision shall be made for bend- Built-Up Members ing stresses due to eccentricty, if any, in the disposi-tion and section of base metal parts and in the loca. 8.12.1 If two or more plates or rolled shapes are used tion and types of welded joints. The disposition of to build up a member, sufficient stitch welding (of the fillet welds to balance the forces about the neutral axis filigt, plug, or slot type) shall be provided to make the or axes for end connections of single-angle, double. parts act in unison as follows, except where transfer or angle. and similar type members is not required; such calculated stress between the parts joined requires weld arrangements at the heel and toe of angle mem, closer spacing:
bers may be distributed to conform to the length of the 8.12.1.1 The maximum longitudinal spacing of various available edges. Similarly, T or beams fram- stitch welds connecting two or more rolled shapes in ing into chords of trusses, or similar joints, may be contact with one another shall not exceed 24 in. (610 connected with unbalanced fillet welds. mm).
8.12.1.2 in built-up compression members, the
,, longitudinal spacing of stitch welds connecting a plate 8.10 Transition of Thicknesses or component to other components shall not exceed the Widths plate thickness times 4000/%or shallit exceed 12 in. (305 mm)(F, = specilled minimum yield point in Tension butt joints in axially aligned primary mem- psi of the type of steel being used). The unsupported bers or different material thicknesses or widths shall width of web, cover, or diaphragm plates, between be made in such a manner that the slope through the adjacent lines of welds, shall not exceed the plate transition zone does not exceed I in 21/2.The transi- thickness times 8000 6 #When the unsupported tion shall be accomplished by chamfering the thicker width exceeds this limit, but a portion ofits width no part, tapering the wider part, sloping the weld metal, or by any combination of these. (See Fig. 8.10). Freater than 8000/ftimes i the thickness would satisfy the stress requirements, the member will be considered acceptable.
8.11 Beam End Connections 8.12.1.3 In built-in tension members, the lon-gitudinal spacing of stitch welds connecting a plate Welded beam end connections shall be designed in ac- component to other components or connecting two cordance with the assumptions about the degree of re- plate components to each other, shall not exceed 12 in.
straint involved in the designated type of con- (305 mm) or 24 times the thickness of the thinner 3
struction. plate.
I l
1
92/ STRUCTURAL WELDING CODE 8.13.1.3 Web distortions of twice the allowable 8.15.2 Nondestructive inspection. Welds that are sub- )l tolerances of 8.I3.1.2 shall be satisfactory when oc- ject to radiographic or magnetic particle testing in l curing at the end of a girder which has been drilled, or addition to visual inspection, shall be unacceptable if l subpunched and teamed; either during assembly or to the radiograph or magnetic particle inspection shows a template for a field bolted splice; provided, when the any of the types of discontinuities given in 8.15.2.1 or splice plates are bolted, the web assumes the proper 8.15.2.2.
dimensional tolerances. 8.15.2.1 Individual discontinuities, having a great.
8.13.1.4 If architectural considerations require est dimension of 3/32 in. (2.4 mm) or greater, if:
tolerances more restrictive than described in 8.13.1, (1) The greatest dimension of a discontinuity is specific reference must be included in the bid docu- larger than 2/3 of the effective' throat,2/3 the weld j ments. size. or 3/4 in. (19.0 mm). 1 (2) The discontinuity is closer than three times its greatest dimension to the end of a groove weld subject 8.14 Temporary Welds to primary tensile stresses.
(3) A group of such discontinuities is in line such Temporary welds shall be subject to the same welding that:
procedure requirements as final welds. They shall be (a) The surn of the greatest dimensions of all removed when required by the Engineer. When they such discontinuities is larger than the effective throat are removed, the surface shall be made flush with the or weld size in any length of six times the effective original surface. throat or weld size. When the length of the weld being examined is less than six times the effective throat or weld size. the permissible sum of the Freatest di-8.15 Quality of Welds mensions shall be proportionally less than the effcc-tive throat or weld size.
8.15.1 Visual Inspection. All welds shall be visually (b) The space between two such discontinuities inspected. A weld shall be acceptable by visualinspec- which are adjacent is less than three times the Freat-tion if it shows that: est dimension of the larger of the discontinuities in the 8.15.1.1 The weld has no cracks. p r being considered.
8.15.1.2 Thorough fusion exists between weld metal and base metal.
8.15.2.2 independent of the requirements ,of 8.15.2.1 discontmulties having a greatest dimension 8.15.1.3 All craters are filled to the full cross sec- fless than 3/32 m. (2.4 mm)if the sum of theirgreat-tion of the welds. est dimension exceeds 3/8 m. (9.5 mm)in any linear 8.15.1.4 Weld profiles are in accordance with 3.6.
8.15.1.5 The sum of diameters of piping porosity
- O **
- does not exceed 3/8 in. (9.5 mm) in any linear inch of 8.15.3 Welds that are subject to ultrasonic testing, in weld and shall not exceed 3/4 m. (19.0 mm) in any 12 addition to visual inspection, shall be acceptable if in. (305 mm) length of weld. they meet the requirements of Table 8.15.3.
8.15.1.6 Fillet welds in any single continuous weld Ultrasonically-tested welds are evaluated on the basis shall be permitted to underrun the nominal fillet size of a discontinuity reflecting ultrasound in proportion required by 1/16 in. (1.6 mm) without correction pro- to its effect on the integrity of the weld.
vided that the undersize weld does not exceed 10 per-cent of the length of the weld. On web-to flange welds 8.15.4 Welds that are subject to liquid penetrant test-on girders, no underrun is permitted at the ends for a ing in addition to visual inspection, shall be evaluated length equal to twice the width of the flange. on the basis of the requirements for visualinspection.
S t
a
~
94/ STRUCTURAL WELDING CODE Part B Allowable Unit Stresses Part C Structural Details E 91 Unit Stresses in Welds2s 9.7 General in general, details shall minimize constraint against N ote: s ie application of these stresses is modified by ductile behavior, avoid undue concentration of the requirements of 9.4. welding, and afford ample access for depositing the 9.3.1 Except as modified by 9.4,9.5, and 9.6, allow- **"**
able unit stress in welds shall not exceed those listed in Table 9.3.1. 9.8 Noncontinuous Beams 9.3.2 Stress on the effective throat of fillet welds is The connections at the ends of noncontinuous beams considered as shear stress regardless of the direction of shall be designed with nexibility so as to avoid ex-application. cessive secondary stresses due to bending. Seated con-nections with a flexible or guiding device to prevent end twisting are recommended.
9.4 Fatigue Stress Provisions 9.9 Participation of Floor System The fatigue stress provisions shall, as applicable, com-Details of the floor system should be so designed as to ply with the Standard Specifications for Highway Bridges as adopted by the American Association of avoid, in so far as possible, unintended participation in the chord or flange stresses.
State Highway and Transportation Officials (AASHTO) or Specification for Steel Railway Bridges of the American Railway Engineering 9.10 Lap Joints Association (AREA). For bridges subject to cyclic loading, other than highway or railway applications, 9.10.I The minimum overlap of parts in stress-stress ranges may be obtained from Table 9.4 and carrying lap loints shall be five times the thickness of Figs. 9.4a and 9.4b for appropriate general condition the thinner part. Unless lateral deflection of the parts and cycle life. The cycle life should be determined by is prevented, they shall be connected by at least two the Engineer to meet the planned life requirements of the structure. transverse lines of fillet. plug or slot welds. or by two or more longtitudinal fillet or slot welds.
9.10.2 Iflongitudinal fillet welds are used alone in lap joints of end connections, the length of each fillet weld 9.5 Combined Unit Stresses sh 11 be no less than the perpendicular distance between them. The transverse spacing of the welds In the case of axial stress combined with bending, the shall not exceed 16 times the thickness of the con.
nected thinner part unless suitable provision is made allowable unit stress of each kind shall be governed by the requirements of 9.3 and 9.4 and the maximum (as by intermediate plug or slot welds) to prevent buckling or separation of the parts. The longitudinal combined unit stresses calculated therefrom shall be fillet welds may be either at the edges of the member limited in accordance with the requirements of the or in slots, applicable general specifications.
9.10.3 When fillet welds in holes or slots are used, the clear distance from the edge of the hole or slot to the adjacent edge of the part containing it, measured 9.6 Increased Unit Stresses Perpendicular to the direction of stress, shall be no less than five times the thickness of the part not less than When the applicable general bridge specification per- two times the width of the hole or slot. The strength of mits the use ofincreased unit stresses for combination the part shall be determined from the critical net sec-of loads or for secondary or erection stresses, cor- tion of the base metal.
responding increases may be applied under this code.
9.11 Corner and T Joints Corner and Tjoints that are to be subjected to bending a Unless specined in the reneral specifications it is recommended about an axis parallel to the joint shall have their l that the basic unit shear stress in the net section be 65 percent of the welds arranged to avoid concentration of tensile stress basic allowable stress in tension. at the root of any weld.
e . . . --
- O 104/ STRUCTURAL WELDING CODE
)
gl1 1-1/2 e s i i l l g
- 1. To determine the maximum size discontinuity permitted in any joint or weld throat- 6 1
g 1 1/4 - protect (A) hortrontally to(B) --
,$, II. To determine the minimum clearance S
. anowed between edges of discontinuaties
$E. I -
of any size:
b 66
$ ei project (B) vertically to (C) gg.
~ ~
3/4 a
99 psS 0
1
=
1/4 g 66'
,,6 0
h*i l g l l l !! I I I I o 1/2 1 11/2 2 2-1/2 3 3-1/2 4 4-1/2 C - Minimum clearance measured along the longitudinai axis of the weld All dimensions in inches. between edges of oorosity odusioNype discominuities, in.
(larger of adsacent oiscontinuities governs)
Note:
Adjacent discontinuities spaced less than the minimum spacing required by Fig. 9.25.2.1. shall be measured as one length, equal to the sum of the totallength of the discontinuities plus the length of the space between them and evaluated as a single discontinuity by Fig. 9.25.2.1 Fig. 9.23.2.1-Weld quality requirementsfor discontinuities occurring in tension welds (limitation ofporosity and fusion type discontinuities).
9.23.1.3 Web distortions of twice the allowable 9.25 Quality of Welds tolerances of 9.23.1.2 shall be satisfactory when oc.
curing at the end of a Firder uhich has been drilled, or subpunched and reamed; either during assembly or to 9.25.1 Visual Inspection. All welds shall be visuall}-
a template for a field bolted splice; provided, when the '"5P'.cted. A weld shall be acceptable by visualinspec-splice plates are bolted, the web assumes the proper ti n if it shows that:
dimensional tolerances. 9.25.1.1 The weld has no cracks.
9.25.I.2 Thorough fusic,n exists between wc!d metal 9.23.1.4 If architectural considerations require and base metal.
tolerances more restrictive than described above, specific reference must be included in the b!d 9.25.1.3 All craters are filled to the full cross sec.
tion of the weld, documents. 9.25.l.4 Weld profiles are in accordance with 3.6.
9.25.l.5 The frequency of piping porosity in fillet 9.24 Temporary Welds welds shall not exceed one in each 4 in. (102 mm) of length and the maximum diameter shall not exceed 3/32 in. (2.4 mm). Exception: for fillet welds connec.
Temporary welds shall be subject to the same welding ting stiffeners to web, the sum of the diameters of pip.
procedure requirements as the final welds. They shall ing porosity shall not exceed 3/8 in. (9.5 mm)in any I be removed unless otherwise permitted by the linear inch of weld und shall not exceed 3/4 in. (19.0 Engineer. When they are removed, the surface shall be mm) in any 12 in. (305 mm) length of weld, made flush with the original surface. There shall be no 9.25.1.6 A fillet weld in any single continuous weld temporary welds in tension zones of members made of shall be permitted to underrun the nominal fillet weld quenched and tempered steel except at locations more size required by 1/16 in. (1.6 mm) without correction.
than 1/6 of the depth of the web from tension flanges provided that the undersize weld does not exceed 10 i
of beams or girders. Temporary welds at other percent of the length of the weld. On web-to flange locations shall be shown on shop drawings and shall be welds on girders no underrun is permitted at ends for a made with E70XX low hydrogen electrodes. length equal to twice the width of the flange.
6
r
. ? 6
- 1
. UNITED STATES OF AMERICA NUCLEAR RECULATORY COMMISSION BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matter of }{
. }{
TEXAS UTILITIES ELECTRIC }( Docket Nos. 50-445-1 COMPANY, et,al,. }( and 50-446-1 .
(Comanche Peak Steam Electric }{
Station, Units 1 and 2) }{
CERTIFICATE OF SERVICE signature below I hereb_y certify that true and correct copies of By my'S ANSWER TO APPL,ICANTS' MOTION FOR
SUMMARY
DISPOSITION OF CERTAIN CAS CASE ALLEGATIONS REGARDING AWS AND A94E CODE PROVISIONS REtATED TO WELDING ISSUES; LAbt' b ANbWLR IU APPLILANid' blAILMLNI Ur mal tKI AL PAbid Ab IU WHILM INLKL 13 NO GENUINE ISSUE; AND AFFIDAVIT OF CASE WITNESS JACK 00YLE have been sent to the names lilsted below this 14th day of May ,1984 ,,.
by: Express Mail where indicated by
- and First Class Mail elsewhere.
(Copies Of attachnents are being*sent only to the parties and Docketing & Service)
- Administrative Judge Peter B. Bloch
- Nicholas S. Reynolds, Esq.
U. S. Nuclear Regulatory Commission Bishop, Liberman, Cook, Purcell ,,
4350 East / West Highway, 4th Floo'r & Reynolds '
Bethesda, Maryland 20814 1200 - 17th St., N. W.
Washington, U.C. 20036
- Hs. Ellen Ginsberg, Law Clerk U. S. Nuclear Regulatory Commission
- Geary S. Mizuno, Esq.
4350 East / West Highway, 4th Floor Office of Executive Legal ,
Bethesda, Maryland
- Director 20814
, U. S. Nuclear Regulatory
- Dr. Kenneth A. McCollos, Dean Commission Division of Engineering, Maryland National Bank Bldg.
Architecture and Technology - Room 10105 Oklahoma State University 7735 Old Georgetown Road Stillwater, Oklahoma 74074 Bethesda, Maryland 20814
- Dr. Walter H. Jordan
- Atomic Safety and Licensing Board 881 W. Outer Drive Panel Oak Ridge, Tennessoe 37830 U. S. Nuclear Regulatory Commission
. Washington, D. C. 20555 t
1
m i ." *'
o N. s Alan S. Rosenthal, Esq., Chairman Renea Hicks, Esq.
Atomic Safety and Licensing Appeal Assistant Attorney General Board Environmental Protection Division U. S. Nuclear Regulatory Commission Supreme Court Building Washington, D. C. 20555 Austin, Texas 78711 Dr. W. Reed Johnson, Member John Collins Atomic Safety and Licensing Appeal Regional Administrator, Region IV Board U. 5. Nuclear Regulatory Commission U. S. Nuclear Regulatory Commission 611 Ryan Plass Dr., Suite 1000 Washington, D. C. 20555 Arlington, Texas 76011 Thomas S. Moore, Esq., Member Lanny A. Sinkin Atomic Safety and Licensing Appeal 114 W. 7th, Suite 220 Board Austin, Texas 78701 U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Dr. David H. Bolts -
2012 S. Polk Michael D. Spence, President Dallas, Texas 75224 Texas Utilities Generating Company Skyway Tower Atomic Safety and Licensing Appeal 400 North Olive St., L.B. 81 Panel Dallas, Texas 75201 U. 5. Nuclear Regulatory Commission Washington, D. C. 20555 Docketing and Service Section (3 copies)
Office of the Secretary U. S. Nuclear Regulatory Commission Washington, D. C. 20555 2dn =1Y flAh (g>t.) Juanita Ellis, President CASE (Citisens Association for Sound Energy) 1426 S. Polk l 1
l 2
.- j
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