ML20080E723

Testimony of D Stiner & H Stiner Re Open Welding Issues

ML20080E723
Person / Time
Site:	Comanche Peak
Issue date:	02/07/1984
From:	Stiner D, Stiner H Citizens Association for Sound Energy
To:
Shared Package
ML20080E713	List: ML20080E710 ML20080E716 ML20080E719 ML20080E723
References
NUDOCS 8402100085
Download: ML20080E723 (47)

Text

{{#Wiki_filter:._ ' o r e UNITED STATES OF AMERICA 2/7/84 NUCLEAR REGULATORY COMMISSION BEFORE THE ATOMIC SAFETY AND LICENSING BOARD In the Matter of APPLICATION OF TEXAS UTILITIES I I Docket Nos. 50-445 GENERATING COMPANY, ET AL. FOR AN OPERATING LICENSE FOR I and 50-446 COMANCHE PEAK STEAM ELECTRIC I STATION UNITS #1 AND #2 I (CPSES) TESTIMONY OF CASE WITNESSES DARLENE STINER AND HENRY STINER 1 Q: Do you have testimony regarding the open welding issues in this 2 proceeding? 3 A: (Mrs. Stiner): Yes, I do. 4 A: (Mr. Stiner): Yes. First I'd like to clarify the record regard-5 ing some of the things which were stated in Applicants' Summary of the Record 6 Regarding Weave and Downhill Welding, filed July 15, 1983, and then to further 7 clarify some of my previous testimony. 8 Q: Mrs. Stiner, what do you wish to clarify? 9 A: (Mrs. Stiner): I 1as certified to weld to both ASME and AWS Dl.1, 10 both of which are used at Comanche Peak. ASME is used for Class 1, 2 and 3 11 hengers and supports; it's not used for Class 5. AWS Dl.1 is used for Classes 12 4, 5, and 6 -- anything that's not safety-related. 13 Q: Isn't Class 5 safety-related? 14 A: (Mrs. Stiner): Procedurally, no. Logically, Class 5 should be 15 considered safety-related, because the' Class 5 hangers and supports are all 16 in safety-related areas, to the best of my knowledge. 8402100085 840207 PDR ADOCK 05000445 O PDR _

r i o 1 Q: Mr. Stiner, what codes did you work to at Comanche Peak? 2 A: (Mr. Stiner): I was also certified to weld to both ASME and AUS 3 D1.1 Codes. As Darlene Stated, both of these Codes are used at Comanche 4 Peak. 5 Q: And is it also your understanding that ASME is used for Classes 6 1, 2, and 3 hangers and supports, but not for Class 5, and that AWS Dl.1 7 is used for Classes 4, 5, and 6? 8 A: (Mr. Stiner): Yes. 9 Q: What specific codes and procedures did you use at Comanche Peak? 10 A: (Mrs. Stiner): WPS 11032,10046, and 11065, and CPM 6.3_ plus 11 quality control procedures (it's been a while, but I believe the numbers 12 of the ones I used primarily as far as QC control procedures were QI-QAP-13 11.16-1 and ANSI Code B31.1). 14 A: (Mr.Stiner): As stated in my testimony (Tr. 4210/16-24),the 15 welding procedures for the C-10 and A-10 welding process codes are 11032, 16 11065, and 10046. 17 Q: What else would you like to clarify? 18 A: (Mr. Stiner): The first time we testified, we didn't have time 19 to put every detail in our testimony and (although I'm not putting CASE 20 down in any way -- I think they've done a fantastic job) CASE didn't know 21 enough about what we were talking about to be able to help us put into the 22 right words what we wanted to say.JAnd we didn't know about things like 23 rebuttal testimony then. We thought everybody understood what we meant, 24 but from some of the Board's Orders which I have read, it is very plain to -25 see that we were not fully understood. Therefore, I-will now attempt to

r , 1 clarify my testimony. 2 I previously stated in my testimony that inexperienced welders were. 3 doing some poor and/or illegal welding practices.qt. Comanche Peak. I know 4 now that a skillful welder is one who possesses a considerable amount of 5 technical information. Merely being able to run a pass or make a good bead 6 is not enough, because in the process of making a weld he may, from lack 7 of understanding, jeopardize the strength of the welded structure. Conse-8 quently, such factors as properties of metals, expansion and contraction 9 grain growth. effects of heat, and others should definitely be considered 10 essential knowledge for any welder. I was not trained by Brown & Root to know 11 these things. I was not even given a written test; the only requirement at 12 Comanche Peak is to pass a three-position plate test, which only requires 13 the ability to make a good bead. All of the welders at Comanche Peak are 14 trained in the same manner and, according to the ASME Code, it is up to 15 the Applicants to assure that each welder is qualified to do the job, not 16 just make a good bead but to. understand all of the process. 17-Q: Mrs. Stiner, do you agree with Mr. Stiner's statements? 18 A: (Mrs. Stiner): Most definitely. I was trained the same way, 19 and the test was the same. Most of what I learned, I learned for myself 20 by reading and trying to improve my skills. I have recently found a weld-21 ing manual that George Baird had me buy while I was in training for welding 22 (SMAW). I was having some problems with my welds, so Mr. Baird ordered me 23 to buy a copy of WELDING SKILLS AND PRACTICES, published by.the American 24 Technical Society, to help me with my training. (I believe it cost $9.00.) 25 Mr. Baird said he thought it was about the best welding book he had seen t e

l o

l. i i

I I and that I should use it at CPSES. It did help me at that time, and I hope l 2 it will also help the Board members to better understand some of Henry's i l 3 and my testimony. We have attached as Attachment B to our testimony some j 4 of the pages from it, and we will be referring to them in our testimony 5 later. Also, we hope to.be able to bring to the hearings some actual weld-i 6 ing tests te show the Board just what we're talking about. { 7 As I received additional certifications, and especially after 8 I became a QC inspector, I learned more and more by reading and trying to 9 understand the importance of what I was doing. j 10 A: (Mr. Stiner): It helped me a lot to understand why welding was 11 supposed to be done a certain way and the importance of doing it right when j 12 I started reading some of Darlene's QC books and procedures. That was when 13 I really began to become concerned about the welding practices at Comanche 14 Peak. And I'm still reading and trying to understand more. At the time 15 I worked at Comanche Peak, I knew that some of the things 1 was ordered to 16 do weren't right, but it wasn't until I started reading and talking with 17 Darlene after she became a QC inspector that I really began to understand i j 18 how bad some of those things were. That's why I decided to come forward and i [ 19 tes tify. It was an especially difficult decision because Darlene was still i j 20 working at Comanche Peak, but when I realized the importance of doing the 1 21 welding right and saw the manner in which the NRC investigators had handled 22 the problems Darlene and I brought op, I knew something had to be done. 23 A: (Mrs. Stiner): An'd e',en though I was afraid I might lost my job, 24 I agreed with Henry that he should testify because I knew that we had to 25 try to do something about the way the plant.was being built. s

i l l l l Weave Beading (Weave Welding) -- HEAT INPUT 2 Q: In their 1/30/84 Reply to CASE's Identification of Issues (page 10), 3 Applicants state that they: " intend to present testimony to address the 4 relationship between the AWS and ASME Codes and the several open welding issues, 5 viz., weave beading, welding of misdrilled holes, downhill welding and weld 6 rod control." 7 Do you have any further clarifying testimony regarding weave beading 8 (or weave welding)? 9 A: (Mr. Stiner): It's obvicus that we didn't make ourselves clear 10 in our previous testimony. There are several aspects of weave welding which 11 need to be clarified. 12 A: (Mrs. Stiner): That's right. During my testimony, I tried to 13 indicate that one of the things we were concerned with is the excessive 14 heat input when you weave weld. 15 Q: Is it still your understanding that weave welding is not allowed 16 at Comanche Peak? 17 A: (Mr.Stiner): That's what I always understood. The procedure 18 that states that weave welding is not to be us?d is CPM-6.9, to the best 19 of my recollection. This is also indicated on the Weld Parameter Guides 20 issued from the rod shack to each welder when material is picked up. If 21 you go over the maximum bead width, you'd be weave welding. 22 A: (Mrs. Stiner): The.one I;used most is 11032. It's interchange-23 able with and often used in place of 11065. 11032 states that stringer 24 beads only shall be used, to the best of my recollection. Therefore, weave 25 welding is not permitted even on the cap or.the root as Applicants have s

. 1 stated can be done; that's the understanding I always had too. It seems 2 to me that if this were not true, Applicants would have brought forward 3 the procedures by now to prove what they were saying (especially since Henry 4 and I discussed this in our 7/25/83 affidavit). 5 A: (Mr. Stiner): But even if weave beading over four-core-wire diameter 6 is permitted at Comanche Peak, there is still a problem because weave beading 7 over four-core-wire diameter is also done. I've seen it done many times and 8 I've done it myself. 9 A: (Mrs. Stiner): That's right. It's a common practice at Comanche 10 Peak. 11 Q: Mrs. Stiner, have you seen it done yourself? 12 A: (Mrs. Stiner): Yes, I have, and I've also done it myself when 13 I was a welder. 14 Q: Please continue. 15 A: (Mr. Stiner): In the process of learning to be a better welder, 16 I have become familiar with the effect of heat as well as cold on the structure 17 of metal and what happens to metal when certain alloying elements are added 18 to it. I also became familiar with what safeguards must be followed in weld-19 ing metals because when heat is applied during a welding process, the very 20 elements originally added to strengthen the meh.ls may destroy them. Metals 21 expand and contract, setting up great stresses that sometimes result in severe 22 distortion. .0, J 23 Improper welding of stainless steel may result in a complete loss 24 of its corrosion-resistant qualities, and welding high carbon steel in the 25 same manner as low carbon steel may produce such brittle welds as to make l

. 1 the welded mass unusable. When I testified before, I used the term " weave 2 welding" (or " weave beading"). Now I know that.was the wrong term to use 3 to describe the problems with welds made at Comanche Peak. The weav'e weld-4 ing itself and whether or not it is done to procedure is only one of the many 5 facets of the problem. Weave welding (or weave beading, as it is called 6 in some books) is one of the ways in which problem welds were made at CPSES. 7 In his affidavit attached to Applicants' 7/15/83 Sununary of the 8 Record Regarding Weave and Downhill Welding, Mr. Brandt stated: 9 "... the only material on which weave welding resulting in excessive bead width is considered to be of concern in the ASME Code is material 10 that requires Charpy impact testing." 11 He then stated that someone (he doesn't state that he personally did it) 12 identified "the particular areas which the Stiners believed contained weave 13 ' welding." He identifies five areas which I had identified and two instances 14 which Darlene had identified. He stated: 15 "Specifically, Mr. Stiner identified five areas in which he contended weave welds existed (CASE Exhibit 666 at 11). These five areas are 16 (1) South Yard Tunnel; (2) Auxiliary Building; (3) North Yard Tunnel; (4) North Pump Room; and (5) Reactor 1 Demineralized Water Tank Room." 17 18 But if you look at my testimony, that's not what I said. What I actually 19 said was (Tr. 4213/7-10, CASE Exhibit 666 at'll): 20 "I told them that in the Auxiliary Building, the North Yard Tunnel, the North Pump Room, the Reactor 1 Demineralized Water Tank Room, 21 and every place I had ever worked, weave welds, porosity, undercut and overlap could be found... unless the surfaces of the welds were 22 ground off and the welds -were. capped (as the I&E Report states)." (First emphasis added; sec6nd emphasis in the original.) 23 24 I would like to say that I worked in the Containment Building in the 25 Reactor and in various parts of the plant were I feel sure impact testing s

l l l 1 is required. I don't remember hanger numbers or exact locations; after you've 2 covered hundreds of welds, you tend to forget exactly where most of them 3 are. I'd have to look around some to find any now. 4 The welding practices at CPSES have got to be changed, and for the 5 foregoing reasons, here is a more detailed explanation of why weave beading 6 (using over four-core-wire diameter) is a serious safety defect., The book 7 which Darlene used at Comanche Peak to try to help her understand more about 8 welding also has some helpful information about welding metallurgy. (See 9 Attachment B to this testimony.) 10 Q: Mr. Stiner, are you a metallurgist? 11 A: No, I'm not. But you don't have to be a metallurgist to understand 12 some things. There is a discussion on pages 19 and 20 of Attachment B about 13 Properties of Materials. I have personally observed welders making repeated 14 passes with a weave bead without stopping to check heat input. When this 15 happens, too rauch heat builds up, which can affect the parent metal subst=n-16 tially. (See Attachment B, pages 20-22, Structure of Metals.) From reading 17 the referenced information, you can see why weave beading of over four times 18 the rod diameter is a defect. If you apply too much heat, the parent metal 19 cools slower, affecting.the grain structure. I have personal'ly observed 20 welders welding without using a heat indicating crayon or any other device 21 to check the heat input. 22 Also, on several occasions, I was instructed to repair hangers 23 where the weld was in excess of four-core-wire diameter where the parent 24 metal was heated so hot that the parent metal for four or five inches out 25 from the weld was blue tempered, causing brittleness. (See Attachment B,

, 1 pages 23 through 28, especially page 28, Brittleness.) On other days, when 2 the temperature was below freezing, I was instructed to make welds on Class 3 3 hangers that were not preheated. The effects of welding on metal not 4 preheated is also a factor in setting up bad welds. (See Attachment B, 5 especially page 28, Cryogenic properties, and pages 23-24, Other Factors 6 Altering Strength and Structure.) 7 The following factors must be included in any testimony about 8 weave welding in order to understand the full extent of the problem at 9 Comanche Peak: 10 1. Too much heat is often applied. 11 2. Impurities are e1 trapped in the weld. 12 3. Most of the hangers I'm talking about were not preheated. 13 4. The interpass temperature was not controlled. 14 5. Unacceptable welding techniques are used, such as weave welding 15 over four-core-wire diameter. 16 6. Weave welding has been done all over Comanche Peak, including 17 areas where Charpy impact testing was required. 18 (See Attachment B: Page 24, Effects of Heat of the Welding Process; 19 Page 31-32, Welding Defects; page 32-37, Residual Stresses, especially first 20 paragraph. ) 21 There is also another example of weave welding which I personally 22 have performed on tube steel type ha'ngers. I was instructed by Fred Coleman, 23 my Foreman (who told me he was. instructed by Forest Dendy, his General Foreman)- 24 to take a welding rod and beat the flux off and use,it to fill in a bad fit-up 25 (too much gap) by placing the bare electrode into the gap and weave welding

. 1 another electrode with the flux still on it over the bare wire. This was 2 all done as an effort to keep from cutting the hanger down and calling the 3 fitters back to refit the hanger. 4 Q: Mrs. Stiner, have you ever made the kind of weave welding which 5 Mr. Stiner just discussed (taking a welding rod, beating the flux off, and 6 using it to fill in a bad fit-up by placing the bare electrode into the 7 gap and weave welding another electrode with the flux still on it over the 8 bare wire)? 9 A: (Mrs. Stiner): Yes, I have. I didn't know how to beat the flux 10 off my electrode and use it as extra filler when I had to weld up a bad fit-up 11 until one of the foremen (Fred Coleman) showed me how. He was temporarily 12 foreman while I worked in the fab shop. 13 Q: Is there anything else you'd like to clarify regarding weave welding? 14 A: (Mr. Stiner): Yes. Regarding weave welding and the heat input, 15 Mr. Brandt says in his affidavit (attached to Applicants' 7/15/83 Summary of 16 the Record Regarding Weave and Downhill Welding)(page P.): 17 "The purpose of limiting head width for welds on materials requiring impact testing is to control effective heat input because excessive 18 heat input could cause broadering and subsequent embrittlement of the heat affected zone." (Emphasis added.) 20 So when we're talking about maximum bead width, we're talking about 21 the effective heat input also. During the whole term of my employment at 22 Brown & Root, the only time that Ijas given a temperature indicating crayon y 23 was in the Welding Qualification Test Center (WQTC),, and I had to ask for it. 24 Q: Is it a requirement at Comanche Peak that a temperature indicating 25 crayon be used?

-l 1 A: (Mr. Stiner): I do know it's required by some procedures. But it's 2 not a practice that is used by the structural welders at Comanche Peak. 3 In regard to Applicants' Exhibits 141N-141V, which Mr. Brandt 4 stated pennit the use of weave welding at Comanche Peak, on those procedures 5 under preheat on the Welding Procedure Specification (4th box, left-hand 6 column), the preheat temperature and interpass-temperature range.is indicated. 7 At Comanche Peak, they don't check the preheat temperature or the interpass 8 temperature. When I tested at the WQTC, they gave me a temperature indi-9 cating crayon to check and be sure that each consecutive pass was not heating 10 the parent metal up above the interpass temperature range which was in the Il procedure. Even on your test coupons if you rise above that interpass tem-12 perature, when they do the bend test on the strips that they'll cut out of 13 your test coupon, you will fail the test because you will have created em-14 brittlement of the parent metal which will show cracks in the weld of the 15 test coupon. 16 But out in the field, I have very seldom seen anyone use the temperature 17 indicating crayons or any other kind of temperature measuring device. I never 18 used the crayons ntyself. Generally, because of my experience with welding, 19 I could tell when it was getting too hot if I held my hand near the metal. 20 But we were under such pressure to put up the hangers that most of the time 21~ we didn't take time to check the temperature. Under one foreman, we had a 22 quota that we had to meet every, day.' I talked about some of the pressures 23 we were under in my testimony (see especially Tr.: 4220-4221)b 24 A: (Mrs.Stiner) The welders didn't have an hour or two to wait for 25 it to cool off; they had to get' the weld made because they had so many to get .s l

i 1 done each day. Plus the fact that they always had to worry about scuebody 2 else coming along and stealing their welding machine or their lead while they ~ 3 went to the restroom or something. At the end.of the day, your foreman didn't 4 understand why you didn't have more hangers done. Most. of the time, the fore-5 man sent the welder to look for their machine and their lead when it was 6 stolen; they didn't have you check out another machine. You might spend 7 hours luoking for a machine that nobody is going to admit was yours. 8 A: (Mr. Stiner) They created such adverse conditions for the welder 9 that he just had a limited amount of time to complete the required amount 10 of hangers. Welders shouldn't have to work under such adverse condition's. 11 A: (Mrs. Stiner) I'd like to say something else about! the weave welding. 12 As an example, if you took a rod and struck an arc and held it to the metal 13 and just kept it burning in the same spot, your metal would just fall right 14 out after a time. Also, the longer you. hold it there, the hotter it gets. 15 So when you weave weld, the longer it takes you to progress up the piece of 16 metal, the hotter the piece is going to be in one specific area. Therefore, 17 the parent metal would become brittle because you are not controlling your 18 hest input. 19 Q: Mrs. Stiner, did you ever use a teriiperature indicatiing crayon? 20 A: (Mrs: Stiner) ' Only in WQTC. I've never used it other than in WQTC. 21 During ray inspections, only a few times have I seen anyone using a temperature 22 stick and that was generally pipe ' welders, heliarcers, and so forth. Most 23 of the time it was not on pipe supports; I don't recall ever seeing it used 24 on pipe supports. 25 Q: How can they check the effective heat zone and be sure they don't re rr. ,s____ __ m _m __m.__m___,_ m __ _ _ _ ______._]

l l 1 get it too hot? 2 A: (Mr. Stiner) They can't. There are other heat checking devices 3 they could use, but they don't use them at Comanche Peak. 4 A:. (Mrs. Stiner) There's no way they can be sure they're not getting 5 it too hot, because they don't use any heat checking devices at all most 6 of the time. 7 Q: How does grinding down help correct weave welding? 8 A: (Mrs. Stiner) It does not. help it at all. The weld underneath is 9 still a weave weld, which is weaker because there has been no control over 10 the. heat input. 11 Q: How could you correct weave welding then? 12 A: (Mrs. Stiner) You grind it completely down to base metal and reweld 13 it with a stringer bead. It would really be better to cut the whole thing 14 down and redo it, because you've still got dainaged parent metal. 15 Q: Was that what you did, Mr. Stiner? 16 A: (Mr. Stiner): No. As I testified (Tr. 4211-4215,4P5-4236,4255), 17 I had to go along and repair bad weave welds that other welders had made 18 most of. the time, and I was told not to grind all of the base metal out 19 but just to grind off the surface and cap it so it would appear to be a sound 20 weld. In other words, it was just covered up, not corrected. 21' Q: Is there anything else about weave welding? 22 A: (Mrs. Stiner): Yes, there's one more thing which needs to be clarified 23 cn page 25 of my testimony, lines 2 through 8 (CASE Exhibit.667, 9/1/82). 24 On page 10 of Applicants' 7/15/83 pleading, it is stated "It is clear that 25 the ' repair' alleged by the Stiners to have been performed was not required l l h. ..i

. 1 because of some structural weakness in the weld or welded material. Rather, 2 the repair was cosmetic, there being no structural reason for limiting weave 3 welding on materials not requiring Charpy impact. testing." I thought it was 4 clear in my testimony on page 25 that the weave welds were discovered when 5 I was inspecting the hanger for torquing; the welds were in the process of 6 being made -- it was not an initial root pass or merely a cover pass for 7 cosmetic reasons, as indicated by Applicants. Later, when 'I returned for final 8 inspection of the torquing, I again.noted the weave welds, which were still in 9 process of being made; they were not merely cosmetic problems, and I wrote 10 an NCR on them accordingly. As stated in rny testimony, the superintendant 11 whom I took to see the welds himself told me to have them cut the hanger down. 12 You don't cut a hanger down for " cosmetic reasons." 13 Q: Mr. Stiner, is there anything further you'd like to say about weave 14 welding? 15 A: Just that it's been a continuing practice at Comanche Peak as long 16 as I can remem ber. And it's my understanding that effective heat input was 17 even a problem identified by the ASME team in, I believe,1981, when ASME 18 allowed Comanche Peak's N stamp to expire. 19 20 21 22 23 26 25 .s

. 1 Downhill '.4elding 2 Q: Do you have anything to say about downhill welding in addition to 3 your previous testimony? 4 A: (Mr. Stiner): Yes. One of my concerns with downhill welding 5 was based on the fact that I was instructed to make downhill welds on hangers 6 that had a limited access weld on them instead of sending me to the test 7 center to test to the criteria for that type of situation. One of the hangers 8 I told Mr. Driskill about is the one I referred to as the one I was fired 9 for. It contained a downhill weld. If anyone had examined the hanger, he 10 could have seen the downhill weld, as I was not even able to get a grinder 11 in the limited space to grind the surface off so QC wouldn't see it. But 12 it was not even addressed by the investigators in their report. 13 A number of downhill welds were made at CPSES because of limited 14 access welds. They were not only made on root and cover passes, but in the 15 consecutive layers in between. I have observed welders making downhill 16 welds because of limited access; one was Roy Combs, under orders of his 17 foreman -- I believe that was on a Class 3 hanger, because he had to weld 18 stainless steel lugs to the pipe. I don't have the hanger number, but I 19 know the general location and might be able to find it. 20 Joe Greene, one of the welding engineers at CPSES, told me that 21 there was no such thing as limited access welds at CPSES. This type of atti-22 tude has set up a bad situationgwitS the welders being instructed to get the 23 work done fast, and the inability to get the proper work and lead angle needed 24 to make the required bead. l 25 One of the problems with downhill' welding is lack of deep penetration, l I

7 I trapped slag caused by the molten puddle falling over the slag coating, which 2 also causes lack of fusion. On heavy plate 1/4" or more, upward welding 3 is preferred (see Attachment B, pages 114 and 115, Position and Movement of 4 the Electrode). 5 Q: Mrs. Stiner, did you do any downhill welding at Comanche Peak? 6 A: Yes, I did. I talked about downhill welding some in my testimony 7 (CASE Exhibit 666, 9/1/82, pages 45-46). I don't think I made it clear in 8 my testimony, but I also have done downhill welding. 9 Q: And is it your understanding that sane downhill welding at Comanche 10 Peak was done illegally or contrary to procedures? II A: (Mrs. Stiner): Yes, probably most of it, because I don't believe 12 most of the welders had been qualified to do it. 13 A: (Mr. Stiner): I'd like to point out that AWS states, regarding 14 downhill welding (see Attachment A, AWS Dl.1): 15 AWS D1.1, 4.6.S: 16 "The progression for all passes in vertical position welding shall be upward, except that undercut may be repaired vertically downwards 17 when reheat is in accordance with Table 4.2, but not lower than 700F i (210C. However, when tubular products are welded, the progression 18 of vertical welding may be upwards or downwards but only in the direction or directions for which the welder is qualified." 19 ~ 20 AWS D1.1, 5.16.5: 21 "For the qualification of a welder the following rules shall apply: 22 5.16.5. A change in the position of welding to one for wh'ich the welder is not. already qualified shall require requalification." 24 25 t

1 AWS D1.1, 5.16.7: 2 "When the plate is in the vertical position, or the pipe or tubing is in the SG or 6G position, a change in the direction of welding i 3 shall require requalification." 3: 4 Q: So ~ downhill welding is not supposed to be used nomally, but only 5 in certain specific instances? 6 A: (Mr. Stiner) That's right. And then the welder is supposed tc be 7 qualified or requalified to do it. 8 Q: Is there anything further you'd like to say about downhill welding? 9 A: (Mrs. Stiner) Whenever you do a downhill weld, you don't get proper 10 penetration -- it's sort of like skiming across the top. I have made down-11 hill welds vself at Comanche Peak, under. orders. Like if I came up on a i 12 weld that was in a particularly hard position to get to, sometimes nty foreman 13 would tell me to.just go ahead and run a downhill weld over y stringer bead 4 14 weld. 15 Q: Were you qualified' for downhill welding? 16 A: (Mrs. Stiner) No, I wasn't. 17 A: (Mr. Stiner) No, I wasn't. I talked about downhill welding some 18 in ray testimony (CASE Exhibit 666, 9/1/82, pages 45-46). I don't think I made it clear in nly testkinony, but I also have done downhill welding. 19 20 Q: But you hadn't been qualified to do it? 21 A: (Mr. Stiner) No,'but I was told to do it anyhow. 22 23 24 25

. I Weld Rod Control 2 Q: Do you have any comments regarding weld rod control at Comanche Peak? 3 A: (Mr. Stiner). Yes. My concern with weld rod control is that if a 4 welder keeps his rods out longer than four hours, the electrodes will absorb 5 moisture which creates a bad weld. For instance, one time I was working on 6 a hanger on the Turbine deck. I had taken all of my rods out of.the heat 7 can and took them with me to the Turbine deck. As I was repairing a weld 8 (I should say covering up a bad weld), an inspector from the NRC came up 9 to me and asked where my rod can was plugged in. I told him that it was 10 located clear down at the rod shack but I could shcw it to him; but he said 11 it wasn't necessary. However, if he had checked, he would have found out that 12 the rod can was not plugged in. A common practice of the welders is to take 13 all of their rods out of the heat can and take them with them, and if asked 14 why their rod can was not plugged in they would say, "Well, I haven't had 15 my rod out of the can 1.nger than four hours"(which is not a violation of weld 16 rod control). But many welders most of the time didn't even put the rods 17 in the heat can to warm them up. On some occasions, the rod shack would 18 issue rods straight out of the open cans that were still cold. 19 I told NRC investigator Mr. Driskill in our initial meeting that 20 if he would go out there, the only way to catch the welder was to find the rod 21 cans unplugged, then record the can number and timo by visually watching 22 the can to see how long it took'.forkhe welder to come back to the can'. And 23 he would have seen that the ' rods were out of the cans for longer tha.n four 24 l hours. On some days I have seen approximately 50 red cans unplugged at the 25 same time. Welders will keep rods froia one hanger and save them.to do repair l

. 1 work on other hangers, and after the rods have set in the welder's tool bucket 2 for two or three days, they absorb moisture and the flux becomes contaminated. 3 I've seen many welders do this. They have very little control over the stubs 4 that are supposed to be turned back in. Welders even loan rods out of their 5 cans to others to do repair work, so the welder won't have to get rods issued 6 from the rod shacks. This is why the welders save a few rods in.their tool 7 buckets, to avoid returning to the rod shacks. 8 Q: Were you ordered to do this? 9 A: No, not directly. The welders do it for convenience. They are I 10 under so much pressure to get the work done and get the hangers up that 11 they try to do anything they can to speed up their work. So even though 12 nobody tells the welders directly to do it, it's encouraged because nobody 13 ever really checks on it or makes a big thing out of it. Everybody knows 14 it goes on. It's sort of a monkey-see, monkey-do sort of thing. 15 Q: Mrs. Stiner, do you have any comments regarding weld rod control? 16 A: (Mrs.Stiner): Yes. Weld rod control is a very important problem 17 at CPSES. Moisture content is very important concerning the quality of welds 18 made on pipes and supports at the plant. When rods are drawn for a particular 19 support, a reasonable number is drawn to complete the hanger. When the job 20 is completed or at the end of the work shift, all rods are returned to rod 21' houses and all rods or used stubs must be counted and accounted for; this 22 is the way it's supposed to be,fone! Without this counting of rods, there 23 is no way to assure where these rods are used or whether they, are ever. returned. 24 to the rod house at all. 25 Q: Is this the way rods are actually controlled at Comanche Peak?

k -N-l 1 A: (Mrs. Stiner): No. For example, on Hanger SI-1-035-032-S35R, 2 this support was referenced in my testimony because the design of the hanger l 3 doesn't warrant the number of rods shown to have been used -- not even it if 4 was taken apart and rewelded over again. I have personally found bundles 5 of unburned rods wrapped in a rubbec band and put in an area for safekeepir.g i 6 and for future use. I turned them in to Harry Williams, who told me to take 7 then to the area foremen and ask if they belonged to them. It doesn't stand 8 to reason that they wculd acknowledge the fact that they. belong to them even 9 if they really did. Everybody knows this sort of thing goes on, but the i l 10 forenen wouldn't openly admit it. It seems to me that Mr. Williams should 11 have known'that. 12 When I started in Class 5 inspection - the rest of my group and 13 I were instructed when doing an inspection that had partially been cut down 14 and rewelded with no IRN (Interim Removal Notice, which is required by pro-15 cedures) in the traveler package', there was no need to verify weld symbols. 16 I would like to point out that if new welds are made on the support and 17 old weld symbols are not removed, QC would be likely to assume that they l 18 still had rods burned on the hanger, making it impossible to have rod 19 traceability. l 20 Moisture content, as stated previously, is very important in weld. 21~ filler material. Welders at CPSES check out tods from rod houses'where 22 cans containing the rods are to be kept heated at all times. E-7018 type 4 . 23 electrodes can be exposed.in'an unheated atmosphere for not more than four ~ 24' hours. ~ This is 'a common type electrode used onsite..In many cases, the cans 25 are never plugged in at cll. Even~ if welders do plug in their cans, mar.y m ^ i wr-y. g-F- 5 y y=-s-4N1 w. g vy w gy viW +r g-w?'e We.- y -e 1y y pg%-wO i 4-*g

A, I times they remove all the rods and carry them around in their stub bucket 2 so they won't need to crawl down off their scaffold in order to get more 3 rods from the heated can; the point being that even if the heat can is left 4 heated, the rods are still subject to moisture contamination because they 5 are not in that heat can, but rather are in an open stub can all day. Also, J j 6 if a welder drops some rods and can't find them, who knows what they will 7 end up being used for? 1 8 I have even personally witnessed an snployee drying his dirty, wet 9 socks in the large stationary rod ovens inside the rod houses. I certainly 10 don't think such a thing is helping the moisture control in the electrodes 11 at all. Workers also heat food inside rod ovens. Also, jewelry and ashtrays, 12 etc., are made onsite frequently. I was instructed by my foreman that Hal 13 Goodson needed some ashtrays and told to make them. I did so along with a 14 fitter. I personally delivered them to Hal Goodson. If rods were controlled 15 at CPSES, how were rods obtained with no requisition? I simply asked for 16 them for Mr. Goodson's ashtrays. 17 I think that the Board may have misunderstood that when welds are 18 made using rods contaminated with moisture, porosity results from this_ and 19 inner passes containing porosity would be covered up. If electrodes contain-20 ing moisture are used, the weld is going to be as bad in the root or inner 21 passes as on the cap. Inspection is not done on the root and. inner passes; 22 therefore, th'is condition would be covered up. Surface examination would 23 not show any inner porosity or anything else. This is confirmed by what 24 the Applicants said in their July 15, 1983, Summary o,f the Record Regarding 25 Weave and Downhill Welding, pages 12 and 13. Although they were speaking 4 "MME-=4'- "PMNW-WuM*NF ""NMP' Jhh ~- - ' ' - ^ - - - - ^ - -

. 1 about Applicants' Exhibit 141H at pages 4 and 6 in regard to downhill welding, 2 it also applies here: 3 ... it is clear that the cover pass is the ~. finishing layer of weld material which covers the underlying werd iayers. Thus, viewing the 4 weld from the top, the wcid passes underneath the cover pass are com-pletely covered and not visible to one inspecting a finished weld." 5 (Emphasis added.) 6 7 8 Plug Welds 9 Q: Do you have any further cannents you'd like to make about plug welds? 10 A: (Mr. Stiner): I was also instructed by Fred Coleman, my foreman, 11 to make plug welds on holes drilled in the wrong place. I don't remember 12 if I made it clear that these plug welds were made in the cable spread.com; 13 I made 20 or 30 at least. There were never any QC inspectors present before 14 or after and my foreman would run watch for QC while we did them. I also made 15 plug welds in other safety-related areas in the plant. I was told to grind 16 the plug weld down to the top of the parent metal and buff the surface so 17 you could not tell it was there, then take a can of grey paint like they 18 use on the metal and paint it so no one could see it. This is what all 19 or most of the welders do. They all know that it is not allowed by the 20 code, but to keep their jobs and to speed up production, they do it anyway. 21 (Mrs. Stiner): I would like to add a couple of items on plug welds. 22 I feel this is a very important issue because when plug welds are done, there 23 is slag entrapped inside the welded area. I don't personally, through personal 24 experience, know of any way to make a plug weld without entrapment of slag. 25 One side is welded, then flipped over to make the other ride weld. When e = w- - * -. -- M w

1 side #1 is welded, slag rolls under and gathers on the bottom of the weld. 2 The piece is then turned over and you have to chip out the slag as' best 3 you can before finishing the weld, thus entrapping slag which is held in 4 cracks, etc. I have made plug welds under orders many times. I have never 5 had QC check on the plug welds I made and I also have never drawn special 6 rods for this purpose. If I was welding on one hanger and the foreman brought 7 a piece requiring pluging to me, he would tell me we didn't have time to 8 draw one rod for this and to just use one of the ones I already had. I 9 don't know where all of these plug welds are now in the plant. I did most 10 of them on fab tables and wasn't told where they were to be used other than 11 what class hanger it was. We ground and painted the surface so QC would 12 not have been able to detect such a weld. 13 14 l 15 16 Q: Do you have anything further to say? 17 A: (Both): Not at this time. 18 19 20 21~ 22 l 23 24 .i 25 t ~ v i L

- - = = = =.. _. - -. = = _ = . = = -

. n.

l

• 411 14 f<

l t ^ ATTACHMENT A I i 3 ~ i ANSVANSDt.181 I =, E:. I l 1 2.; E An American NationalStandard -w American National Standards hotl2ute \\ Structural Weld'ing Code-I l r Ste'el' v-Fifth E&uos ) Sepersedia , AWSDIJ.Se + l I*Pai by [ l AWS Structural Welding Comnunce CT j .a. l T Under the Direction of j AWS Technical Activiests Comnunce 3,. j Appruved by. y AWS Baard of Desecum 7, EHecuve January I.1981 ~. J \\ 3 .i -t . l.. ~

• .'. ? :.

...n 1 = i a } A' w l k AREE3WCAN WELDWeG SOCETY.NGC. l1 250l N.1ht7sh Seest.Mammi.FL33125 i l .l .f,

%,e 9 :. :... i .d ATTACHMENT A \\ .i. 3mbamersouf Are IMrldingI$l a' this4.5.3 4.4.3.4 S/32 in.14.0 mmi for melds made with w PervelseRita absteepherte espesure of EXXI4 and noe hydroien electmdes is the verucal and k leurIvydrogen elospodes perhead pasmons. t 4.4JJ 3/16 is. f4.8 mmt for root passes of groose M Catwas Calena melds and for all other melds not included under 4.6.3.1. A B 4.6.3.2. 4.6.3.3. and 4.6.3.4. 1 Eircmade obissi-eburis . q* 4.4.4 The manimum stas of a root pass shall be sufG. AS I . cient to preent cracking. EMXX a unas Owe 4 k 10 mas 4.6.5 The maumum thickness of root passes in grouve ..g l l~ melds shallbe l/4 :n. 36 nsm). 1 d AS.S. j 4.6.6 The masimum size of single pass Ellet meus and j.D ,' [,, root pmes of mulnple. pass filles ocids shall be = g 3 s y,n n o,,,,, 3,,, 4.6.6.13/8 in. t9.5 mme in the flat posmon O ElcC R t/2 m n Owr II: had mn M4.2 $/16 in. 48.0 mmi in the bactzontal or pier. ?- EIlon 1/2 m n Oser 1/2 m.a nin kad posinons 4.6.6.3 II:in. s 1 1 mme in the scrucal posinon Nurs:

8. Colisen A Eireinors esrswed 6. aawgmere f. t king,,

.s4.7 The maumum thicknen of layers subsequent to pernmh chan samma shri he maried term sie root Passes of groose anJ fillct melds shall be i .t

2. Catens 5. EArosaars eweed 6. sowiphere f.=r k nger 4.6.7.11/8 in. t3 mme foe sut>scquent layers of melds i

Permade than isame esambariNd t'> eruing shat te sedres hr. mm.le in the flat popuan 1 8==r ame-4.4.7.2 3/16 in e4 mme for subsequent layers of meUs l made in the scrusal. ombead. or horizont.at posiuons j i 44.8 The progresuon for all passes in sertwal pouuon - l 4.S.4 aadrvtag Deetrodes. Electrodes that eonform to meurns shall be upmard, escept thai urkiercut may be .J she prwssaons of 4.5.2 shall subsequently be redried repaireJ scrtwally Joa nmards mhen preheas es in a:ecn!. t no enore than one ome. Electrases that hair been met aner with Table 4 2. but not louer than v F :1* C i shall act be usad. Ikm.eser. m hen tuttlar penfuets are meUcJ. the progres. Y i a l 4JJ MammEmesereri Cert 1Acaties. % hen requestcJ by sion of sertwal me! Jing may be upmards or Joanmards } 'O'*"d"*#"***I""" the Enpneer. the contractor or fabricator shall furnish ,g; - as electrode manufacturer's ccmfication that the electrale l till meet the respatrements of the classificanon. 4 6.9 Complete rint penetranon prome aclJs male with.

L l

out the use of steel baeking shall hne the ra>t youred a i l l #C to sounJ metal before melding is ss.arted from the second 4.6 Prnewehires for Shielded "d* ""P' P'""'"*d b) ' E i Metal Arc Weiding ~ f 44.1 The merk shall be posmoned for fia: pouuon melJ. PhrtC s '** "** F"'**'* SubmergedArc Weldblg r 44.21he classific:non and use of electrate, are length. vidiage, and amperaje shall be suited to the thickness of ,g the maserial. type of groote. melding possuons. armi 4.7 GeneralRMulrements asher circumsaanors sesendang the work. %iriding current shall be wishia she range recomtnended try the electrode ,,,,,g,,,,,, 4.7.1 Submerged are melding may be. performed with I 4 one or enore ungle electmdes, one oc more parallel elcs. p ..A,f l 44.3 The maximum diameter of electrodes shall be: trades." oc combinsuons of single armi parallet electrodes as follows: The spacing besmeen arcs shall be such that the slag cover h 4JJ.I S/16 in. II.0 mmt for all me:4s made in the oser the meld metal produced by a leading are does not .J, fler poemon.sacept rom passes. cool sufficient!) to prevent the proper weld deposit of a 44.3.21/4 is. (6.4 mmt for bortsgatal fillet melds. folleeing elecimde. Submerged arc melding mith armil-U 4JJJ 1/4 la.16.4 samt for root passes of fillet ople electrodes may be used for any grome or fillet solda made is the flat posioon and groove melds trade , eld paas. -P .} to the flat posioon with backing and with a root open. d i j seg of 1/4is. er more. II. Ese AppendasI e l u ' 3. c 045 8~8 M ~ .- brch ..,---v.-

^ Ch j' ATTACHMENT A 16fouaunemou . :s (I) Partial joint penetruien groow welds shall how 5.13 Records -*i '. the designeaud eflectiw thsoet. QI Fillet welds shall how fuion to the sont :sf the Itecords of the test results shall be kept try the menu. 5 eneet the specified Ellet I hoe e amine s m. edid saae. MIThe persial joint penetratsun 3mme melds and ? fillet wends shalt: 3 (al Haw so encts. 5.14 Retests ' (b) Haw thorough fuson besmeen adjacent leyers of we4d metals and between weld metal and baw metal. (c) Have weld proGles conforming to intended de. If any one specirnen of all those neued fails to meet the tail, bia =nh anne of the iariasems prohibued an 3.6. wu grrem tuo newus im p&r w d tese specimen ma) be performed e ah specimens cus from d aw no madercut escreding t5e salues permit. the same procedure qualifcation mmerial. The resuka of 3 both test specimens must meet the its requiremenn. For S.12.4 AMbidd.Matal Tesalem Test ielectinales and material owr I I12 m. 08.1 mms thick, fadure of a spec. ehemegnal. The mechancal psoperties shall be rui lew imen shall require seuing of all specorreas of the sant sham those specified am 4.16. ty pe from emn addianomal incations in the snt enarerial. S.12.5 Namduaractive Testing. For accepaable gehn. cuana, the weid, as rewaled by radeographc or ultra. somie testang. shall confonn so the requarmenn of 8.13. 9.25. or 10.fl. =hchever is applicable. ".O S.12.6 Vlamel ? "- Flye and1hbies. For accept. able quahfcmion, a pipe weld, m hen inspected sssually. T'.. shall consona ao the followseg requirements: (II The weld shall be free of tracks. f,. gg Q) All casers shall be fdled so the full cans sectum ettse w n. WeiderQualtfication \\ Of The face of the weld shall be at least flush =sth I she oesade saface of the pipe. and the meld shall energe j

==arkly with the case metal. L.'ndercus shall not escud 5.15 Geners! J, t/64 sa. O.4 anal. Weld renforcement shall not esceed the followiag: w The quahrication teus dewribed in Part C are specially W desswd tesu to determine the melder's abihty to produce ? sound welds. The qualifcation ersa are not eneraded so Pipe oa!!:hckarst. Reinfunement. enas. be uwd as a guide for meldang during actual construe. " ~ ' " " " j tion. The latter shall be performed m accordance wah 315 t9.38aelesa 3:32 24 the requiremenn of the procedwe specincaten. l O=er 3/s ao 3M it94s mel. Ira 32 4 ~ l 4 Owr 34 3*l6 44 5.16 Lhnitation of Variables l S. 9 H) The sees of the weld shall be inspected. and there f shall be ao evidence of cracks encomplete fusen, or For the quhreaten of a melder the follonias rules saadeqesse joint penetrataos. A concave root surface is shall apply: penruned ekhim the inans shown belom, provided the 3.16.1 @linem cumbliM mkh w w of the thickmesa is equal so or greaner than that of the steels permined by this Code shall be considered as qua acs wid onack wW any of tk & nuA UIThe enesirnurn mot surface concavity shall be I~ 1/16 in. (1.6 mm) and the maairnurn melt thru shat! be 3.16.2 A welder shall be goalified for each pmcess used. I . O.2 mm!. 3.16.3 A welder qualified for shielded metal are wekim 5.12.7 Vissal *. " _ Flase. For acceptable quali. =ith an electrode identified in the folkywing table shall be flemira, the welded test plane, when inspected visually, considered qualified to weld or tack weld wkh any othee 3 shall cos8erus so the sequeremeses for visual inspectaan electrode in the same gsoup designation and with any ks 9.23.I. electrode lisand is a surnerwally lower group designation. l 0499 M*

• l

..,.c ATTACHNENTA l awdreo.afscera=137 r l osungt AW 3.!7J The wekler who makes a complete joint penetre-druemanima electrode etassirwsmin* tion plate groow weld pmeedure qualifwame erst that f F4 EXXIS. EXXI6. EXXII "9" W 9"' F3 EXX10.EXXil Process and out positaan for ph and squam or me-1 F2 EXXI2.EXX13.EXX!4 tongular tubing equal to of less than the thickness of the FI EXX20. EXX24. EXX27. EXX 23 test plane welded. If the nest ptase is I la. (25.4 mm) or g. a gnaser in thickness, the welder will be qualified for all - u-

• The treevs XX* umed ia tte classarensen desegnaisin in th",-

thicknesses. The welder is also qualified for fillet 'N 6 meer naamd sur the urwes seveegth lemels feu. so. 80.90. 300 ,,, g3ggg g,,,g, . welding cf plaar and pipe, as shown ta lhhie 5.23. ~ SJ6.4 A melder qualified with an spprowd electrode 3.17.4 The melder who makes a coerplete joint pene. .1 and shneM sendown combiasson shall be considered Iraton Broow weld pipe procedure qualifemen test. ~ quakfeed so we4d or tack weld wah any other approved =nimin backing ursp. that mens the saimmmean is 4' electrode and shieldsag.nedsam combinasen for the themby qualified for that process. His qualifession mill psocess used is die qualafssson neu. include the test posisson for pipe having a wall thickness equal to or less than the wall th~rkness of the test pipe j 4 5.25.5 A change in the pomason'of welding to one for welded. If the test pipe welded is 6 in. (152 snm) Sch. 30 I 4 which the melder is ace aheady qualified shall requue or 3 in. (203 mm) Sch.120 pipe. he will be qualified for sequahr-all thicknesses. This welder is also qua'ified for fillet 5.35.6 A chenSe fiossione diameter mall pipe grouping melding of plate and pipe as shown is Table 5.23. If the shown in 1hede 5.26.1 ao another shall requsre requals. diamener of the job.sua pipe or subsag imed in qualifi. cation as 4 in. Il02 mm s or less. the qualifcasson is Isanard g to dsameters 3/4 in. (19 mma through 4 in. (102 unml. Q S.M.7 Wbes the pinne a is the wrtral positen or the inchrsive. If the dsameter of job. sue pipe k aner 4 is. 3 pipe or esimag h as the SG or 6G potame, a change in (102 m.n), the qualificassen is limited to a minunwn she duraction of meldsag shall ristuue squabfsaten. diameter of grenser than 1/2 test dammeier or 4 is. (102 5.E.8 The osshnana of backir g masenal in. complete mm). =hchever is larger. The mall thickness qualified ini=

== ids ocided f== one mee shall m-j,,,",""73w3s,i. ' * ' * ' 'sPecnnens aquind shan be m T gm. p.lir=m 'e MWhW 5.18 Groove Weld Plate Qualification h.( ~ SJ7.3 The welder qualifcation aesa for saanual and Test for Plate of Unlimited m= ar==re weldseg shall be as follows: Thickness 5.U.1.1 Grosse==id apsalifemica nest for place of "*'"*"'dM"*** The joint detail shall be a follows: I in. (25.4 mmt 'l SJ7.1.2 Groow weld qualificauon nest for pide of place, single.V groon. 45 deg included angle.114 in. ~ SJ7J.3 Fallet meld qualifca. ace sens for fillet = elds 16.4 mmi root opening with backing (see Fig. 5.18 A). andy For horW posinen quefemiosi. the fois detail l f (1 ) For = elds is joints having a dihedral angle (di of may, at the contractor's opten. be as folloms: single. l 75 deg or lens, qualificarax. isses shall be as seq uired by bewl. groom 45 des procne angk. He in. root openias l l 5.5 or 5.I9. Sech qualifcanon mill be valad for fillet math backing tiee Fig. 5.1881. Backing must be at least l

• • Id5 8"nas angles gnaser than 75 deg.

313 in.19.5 mmt by 3 in. f76.2 mmt il radegraphe - M! l Q3 For swelds is joints having a dahedrsl angle del testing s used without rernovs! of backing. 't naast be pseaser than 75 des and not exceeding 135 deg, tests sha!! at least 313 in. by I in. f25.4 mmi for mechancal testmg he as seguired by 5.22. Opuan I or Opuon 2-cr.mtractor's or for radeographic testing aher the backing is remowd lvtinimum length of welding groove shall be 5 in. 5 4.,

• F'"8 -

(127 mm). 5.ff.2 The pipe or tutzag qualifestion tests for manual p l and sensasanommic welding shall be as follows: l s.n.2.1 omo= weid q=Iirsauce au for hun joinu 5.19 Groove Weld Plate Qualification .s as pg' ie or sesare or :=e' angular tabing Test for Plate of Wted i P e, 5.U.2.2 Oreow evid qualifiesman neu for T. K. or Y.commsetens os pipe or squam or rectangular tut >ing h S.U.2.3 Groow weld qualifemian nest for bustjoints c q 9 es square or sectangular tubeag assand on fim plass The joint detail sha!I be as follows: 3/g in. (9.5 mm) u. ~ ~ h, 0500 '3' l . - - - - - - + - - --_-------ow,----,- ---,--a nww n

4 ATTACHMENT B h. 4 en a,n.;. ~ y 4 Y h ?&v-m s e p 12 ir" g E / 4* 1 8 / f hI

s. FTE**"~ ~ ~ ~

mm w ..k. T 4 g _, c+.. p,,k s g t0 f% ?? h a: h k f,

• • ..{!.

' Q_ ~& - %,~,%?.- Q,h '.h ?fh ?.$.)?* W .Mll'[.5.5-*:f f ? "; ;. jbps?- ': ? [ ,9%(f.h.F.1. ;2:s..,'.;: , 'jg f.i, .; p. ,j,- y i-c s j, ' P v.. ;- ( ' '.g 4% , - /. f l '.,%h h f.n..h hlL;.'N... ?_ $g% T h.....:. O.h,. , g %{i:f.A$ ; ' f ne,l (; Y . d~"L, .1 < r M- +. - c1 a c 9 ',*. :.p* ~.,

? ..+ :M

-,=. = ..':$ af.y^4" .s

• /

W ..'..D*.3 pgr',,f e f l, [Nt{,, 4-r A ,;,1* y .~ f., x Le(py,' i .7[;..; ,%; ]f-..

e. v.,2

s,

. -c% ' - -g',., 4 'g..'. , g/,. ' ,u. -;w- ,_r y ). }4W

• >.mq-

.,n ..,.'.o,

1. -,.., ?

v w,. e. r.,v., - ;. s - - ,t,. ~ 9 g .4. .b.s. ay. -u.4 g n . 5, %. 3f.--* ):._.f.d-..) '.: i: '.': r f,;;,W,

• l:. 6.. /y ;[,0.. t. ?;hu~-R,,%9. '...

.p t ' 1., sm, A. c %,feT; V ' c..,e . p. t. 3 , p.e L c.;-

• .~s:*..,"4

? s. e 7,. g _ \\.. w 9.. ",y .s..:,. _.;,. .3... f. g,f ,.. r ..7 . u- + ,,,.. " g ' s . =43. e u .L 4'.* z.+ &y " 2, i-; '.'

7'; -<.',...,',."5 7.g. ' *. < ; g/.'

.. K 'e g h, '.,' J,e,(' f N, 4,,'-. f, ".go. y., ' ',, * [. ;; i. -. .e[s ., ~ ,,4g, ; 5 4 $. 4. '. r.+c..,. ,6., .o ' f ;y ,'.7.'. J' c i yg-r - z ..w p sg _s- -...,. f, *..- 2, -T. .. g,., s. 49 :,,.

• y s.

p.- g," e 4,.,:- w $+L l,..A, # :: ? ,k - : s 3,5.,.,,.',, -. p- , ' : : :..,..u.;,... c. ;<. ...-y.-

- x a m -

%,..-y.: ,... m: t i w ne r .s W;:l@M 2;f.i.W?'a. SOS ? Df iR M+. u, -- 3 -. % :O 'u:. s- - w Qg'ftl$)$.C ::L.l.?,;.'._' 'yD -i: 8h .:?i

:-' t.

. n=a :.... {.Y,2.L*$." 5 ~; Y ;.glY,- .c d%

y

i...

. ' :: ' r. 2,. p > : :.,- L ^ 9 l-{.?.,}? '... " ; : 'i ~* i Q w;,; e;.,.,,.x. 7,.,.. a~,,e?.g.,.. _ ~. 9.. _c. ..a, ~ u: .x ....y .4.;. n<...._. - s~

.v,

1 .,.. p...,- y 9.~ t

N $. ' f:?, ' f & -p?.. '.,'. 2h>l'** l. '...,?._'L A ~ $' >.... %:

4.. c

1. ,.,r g. g: &:p. &,.,.+ y N l)l -l '. f.-R y. M,. 3.

~ 7.,.,,.,.s ? b. w. n l,@ % &.rt. 9.. '.*~.,,: V,. ;.. '< v: y, h.v.GQ, - y n, .r c .? -. m. w :.. w. .g ..a.m.., :..-..4 o,.AS.c, e c s. .,. e 4;, ' i ',: ' :; lf.. b a. "; ' . }'f..;hf;f < '..f%lffNk 'l.h

_Rl.

I..Y.Y f Y b f, G f. ck n-evenf -:[b'-.

A ~ s v - c.% 1 m 1: -) N </ h dl. '; VQ.Q:hiQ[c 3.#: N dh;.:

.e,fi_&[k:N.'I } } Q : y y Q c f } f F g fb Q

. v.: ':S .. w p.n, N,'h'hi;. [... e,. ~e. s: U M,h;( ,i t Jossoh W. Giachino, William Weeks Western Michigan University Kalamazoo, Michigan J, ,LI il i Amencan Technical Society CHICAGO, ILL. 60637 l

r: m m,m a 1 ATTACHMENT B t; introduction to welding G APTER 3 meldins metallurev I In preparing to become a skillful welder you welding techniques. These properties can be should become familiar with the effects of heat defined as fo!!ows: on the structure of metal and with what happens Chem / cal propert/es. Chemical properties to metal when certain alloying elements are are those which involve corrosion, oxidation, added to it. and reduction. Corrosion is a wasting away of You will also need to know what safeguards metal due to various atmospheric elements. Ox/- must be followed in welding metals because dation is the formation of metal oxides which application of heat during the welding process occur when oxygen combines with a metal. may destroy the very elements which were origi-Reduction refers to the removal of oxygen from nally added to improve the structure of the the surrounding molten puddle to reducJ the metal. For example, metals expand and contract, effects of atmospheric contamination. thereby setting up great stresses which often in any welding situation, it is important to result in severe distortions. improper welding of remember that oxygen is c highly reactive ele-i stainless steel may result in a complete loss of its ment. When it comes in contact with metal, j corrosion-resistant qualities, and welding high-especially at high temperatures, undesirable ox-carbon steel in the same manner as low-carbon ides and gases are formed, thereby complicating steel may produce such a brittle weld as to make the welding process. Hence, the success of any' the welded piece unusable. welding operation depends on how well oxygen l T%pTeedeats-wittube-met eld-can be prevented from contaminating the molten l yrgr#raNs. the formation of impurities and the metal. l 1 l effects of heat on the chemical, physical, and Physicalpropert/es. Physical properties are mechanical properties of metals. those which affect metals when they are subject to heat generated by welding such as melting ~ W, ~" point, thermal conductivity, and grain structure. PROPERTIES OF MATERIALSu Solid metals change into a liquid state at differ-ent tempe atures. When cooling from a liquid l Chemical, physical, and mechanical proper-state the atoms will form various crystal patterns j ties have a very significant influence in any (lattices). The strength of a weld often depends welding operation. This will become more ap-on how these lattices are controlled and how parent in later chapters dealing with specific much heat is necessary to produce proper fusion 19 1

. - ---, e m. w,, , -w. t( ATTACHMENT B 23 Introduction to Welding of metal. Equally important is being aware that ~ - -dm.www.d. &v,E&_Q~f 6;&h% some metals have a high rate of heat conductivi- .tl 9 ~ [j[;,p$gfjf sm,p'y g f-; j y I ty while others have slower thermal conductivity. Also a welder needs to understand how heat will !:k-MF' _ ]-)%.;[f } affect the grain structure of metals since the M~ 1 j@ hh f$~ [ {-~f grain size of the crystalline structure has a direct h f'^ lN7,. bearing on the strength of a welded joint. M l l3 - "t %D{ gt J 7 y Mechanical properties. Mechanical proper-f ,l_.

Q

p l

ties are those which determine the behavior of -a metals under applied loads. These include a 1 l wide range of properties such as tensile strength; ductility, toughness, onttleness and I others, all of which are extremely important in l-their relationship to welding. 4 STRUCTURE OF METALS ,.c.F When you examine a polished piece of metal E under a microscope, you will see small grains. h, 9 Here s the anangement f at msin a bo& centered Each cf these grains is made up of smaller cubic crystal. particles, called atoms, of which all matter is composed. The grains, or crystals as iney are often called, vary in shape and size. The arrangement of the

---

~c Q

atoms determines the shape of the crystalline b structure. In general, the crystals of the more p 2 common types of metals arrange themselves in l l three different patterns. These are known as l _M l' space-lattices. l l r A space-lattice is a visual representation of the l l j, orderly geometric pattern into which the atoms l j-- - - _ - 1-- W - of all metals arrange themselves upon cooling (

c. l /!

The first type of space-lattice, illustrated in i .hll ' ly.. y from a liquid to a solid state. f l-4 Fig. 3-1, is the body-centered cube. Here you will h /; j l-find nine atoms-one at each corner of the cube

i. /!

/3 l s, and one in the center. This crystal pattern is j (j ---k #---,+-- --- -. i. j j found in such metals as iron, molybdenum, j/ chromium, columbium, tungsten, and vanadium.. p------- i '----~ The second crystal pattern is the face-j gh }I u. ./wec r-E /P - - centered cube. Notice in Fig. 3-2 how the atoms / D h"' are arranged. Metals having this space-lattice pattern are aluminum, nickel, copper, lead, plati- ^ v Y( P.' Cr< num, gold, and silver. The third space lattice is called the close Fig. 3-2. The atoms in a face-centered cubic crystal assume packed hexagonal form. See Fig.3-3. Among the this arrangement. 1

ATTACHMENT B p Welding Metallurgy 21 ~ --vi tern. Some-metals may even change from one .g-l3,* kNEYtFf k i crystal structure to another crystal structure at 9 yeg.# W:dh-various temparature levels. For example, iron G 4p s @ Ydh.- when heated changes completely to a face- ? q.O, A i,, j, % %ql,y % M ,., ' $1 %p centered cubic structure at a temperature of ,k y ',-5O. e;: yb g gm 1670*F [910*C]. v ,, yg. ~ ~4 As liquid metal is cooled it loses thermal ,y. .x ,i r I: energy (heat) to the air and walls of the contain- }l er. At the solidification temperature the atoms of the metal assume their characteristic crysta! l ~ r l l l structure. Crystals begin growing at random in i a the melt at points of lowest energy. If the rate of l l cooling is f ast, mors crystals will form instanta-l

y l

neously than at slow rates of cooling. The more jl' i crystals that are growing simultaneously the (

---

l----

finer will be the grain size of the metal. l; i Grain size is important since fine-grained i l; l steels have far superior mechanical properties l than coarse-grained steels. Hence, it is impor-i lr l l. ~ -l -l 6 parent metal. The use of excessive heat leads to tant for a welder to preserve the grain size of the jjQ 'l' A '1 a slow rate of cooling, thus producing coarse [- .P t' u: Heating Effect on Grain Structure of Steel 3 f When steel, which is carbon and iron,is heat- @g

1 ed from room temperature to above 1333' F

[835'C], the pearlite grains change from a body-Fig. 3-3. This is the arrangement of the atoms in a hexagonal centered lattice to a face-centered structure. close-packed crystal. Such an arrangement of iron atoms is known as gamma iron. What has happened is that while the steel went through its critical temperature (temperature above which steel must be heated so it will metals having this type of crystalline structure harden when quenched), the iron carbide sepa-are cadmium, bismuth, cobalt, magnesium, tita-rated into carbon and iron, with the carbon nium, and zinc. distributing itself evenly in the iron. The material Metals with the face-centered lattice are gen-is now called austenite. erally ductile; that is, plastic and workable. Met-If the heating is continued beyond the critical als with close-packed hexagonal lattice lack point, the grains grow larger or coarser until the plasticity and cannot be cold-worked, with the melting point is reached. When the steel melts, exception of zirconium and titanium. Metals with the crystal structure is completely broken and body-centered crystals have higher strengt'h but ~ the atoms float about without any definite rela-lower cold working properties than those with tionship to one another. the face-centered pattern. ~ ~ Crystalliz tion of Metals Cooling Effect on Grain Structureiof Steel ~ All metals solidify in the form of crystals. Each ifhuToAl a rietal from a molten state to room ~^ ~ metal has its own characteristic geometric pat-temperature, the change that takes place, under 1 )

s:.,. ,., ~. ATTACHMENT B 22 Introduction to Welding proper conditions, is exs*v the opposite of very brittle, known as martensite. See Fig. 3-4. what occurs while the meno,. heating. Martensite is ihe constituent found in fully hard-As the metal begins to cool, the crystals of ened steel which is hard and brittle. On the other pure iron start to solidify. This is followed by a hand, if the rate of quenching (cooling) is some-y crystallization of austenitic grains, and eventual-what slower, the structure will be much more [ ly the entire mass becomes solid. ductile. i {jl During the range of temperatures at which i 7 various stages of solidification takes place, the i metal passes from a mushy condition to a solid solution. While in a mushy stage the metal can be shaped easily. After it has reached a solid IMPORTANCE OF CARBON IN STEEL state, even though the alloy is still hot, it can be i formed only by applying heavy pressure or ham-l mering (forging). Carbon is the principal element controlling the With continued cooling of the solid metal, the structure and properties that might be expected austenite contracts evenly as the temperature from any carbon steel.The influence that carbon falls. When it reaches its transformation temper-has in strengthening and hardening steel is ature, the temperature drop stops for a time. At dependent upon the amount of carbon present this point there occurs a rearrangement of and upon its microstructure. Slowly cooled car-gamma iron to alpha iron as well as a separation bon steels have a relatively soft iron pearlitic of iron caroide and pure iron into pearlite grains. microstructure; whereas rapidly quenched car-The transformation of the metal from a liquid bon steels have a strong, hard, brittle, marten-to a solid is important because the proper rear. sitic microstructure. rangement of the atoms depends on the rate of in carbon steel, at normal room temperature, cooling. If, for example, a piece of 0.83 percent the atoms are arranged in a body-centered lat-carbon steel is cooled rapidly after its critical tice. This is krinwn as alpha iron. Each grain of temperature is reached, certain actions are ar-the structure is made up of layers of pure iron rested before the pearlitic structure can be (ferrite) and a combination of iron and carbon. formed. The result is a metal that is hard, but The compound of iron and carbon, or iron car-bide, is called cementite. The cementite is very hard and has practically no ductility. In a steel with 0.83 percent carbon, the grains are pearlitic, meaning that all the carbon is combined with iron to form iron carbide. This is known as a eutectoid mixture of carbon and iron. See Fig. 3-5. If there is less than 0.83 percent carbon, the mixture of pearlite and ferrite is referred to as hypoeutectoid. An examination of such a mix-ture would show grains of pure iron and grains of pearlite as shown in Fig. 3-6. When the metal contains more than 0.83 per-cent carbon, the mixture consists of pearlite and iron carbide and is called hypereutectoid. Notice in Fig. 3-7 how the grains of pearlite are sur-l rounded by iron carbide. In general, the greatest percentage of steel used is of the hypoeutectoid type, that which has less than 0.83 percent Fig. 3-4. Structure of martensite, carbon.

s ATTACHMENT B ~ Welding Metallurgy 23 f Zw 2 4 I f' s i 's 2 L . g m l w 9 l ^ , p Fig. 3-5. Eare is how the pearbte grains arrange themselves geog g,,,,,, in a eutectoid mixture. PEARLITI Fig. 3-7. This is an example of a hypereutectona structure. l = r,jsl#5-metal becomes stronger and harder. lf, after cold working, the metal is heated and allowed to cool, the grain size is again increased and the metal softened. The grain size of some metals is reduced and the strength improved through a heating and quenching process. Thus, if a high-carbon steel is heated to a prescribed temperature and than 4 immediately quenched in oil or water, followed D by a tempering process, the grain size remains fine. But if you allow the same metal to heat for a long time or if you subject it to temperatures beyond the critical range, than the grain size increases and the metalis weakened.This point is particularly important to remember in welding various steel alloys. The problem of structural onAINS OF PEARLITE PuREIRON + On the other hand, mioy steels are greatly de-Fig. 3-6. An example of hyposutectoid grain structu're.~' pendent on space-lattice formation and grain size for their strength. Therefore, you must take l extreme care during welding to avoid seriously Other Factors Altering Strength and Structure altering a metal's space-lattice pattern through When a metal is cold-worked (that is; ham-excessive application of heat or improper treat-mered, rolled or drawn through a die) the ferrite ment of the weld during its cooling stages to and pearlite grains are made smaller and the avoid this problem. u..

{ ATTACHMENT B 24 Introduction to Welding Effects of Heat of the Welding Process For some metals, the normalizing treatment is in welding you must realize, too, that one edge used. It differs from standard annealing in that of the metal may cool rapidly, thereby resulting the steel is heated to a higher temperature for in the formation of hard spots which cause shorter periods and then air cooled. cracks or failure in the weld. Also, there will be Stress relieving is a means of removing the conditions where the metalis in a molten state at internal stresses which develop during the weld-one point while the surrounding areas may have ing operation. The process consists of heating a temperature ranging from near the molten the structure to a temperatura below the critical point down to room temperature. This means range (approximately 1100*F [594*C] and allow-that in some areas the crystal structure is com. ing it to cool slowly. Another method of relieving pletely broken down while elsewhere recrystalli. stresses is peeoing (hammering). However, zation is taking place. peening must be undertaken with considerable Keep in mind that when hardenable steels are care because there is always danger of cracking being fused, and you make no effort to control the metal. the structural changes either through preheating Stress relieving is done only if there is a or by slowing down the cooling rate, the com. possibility that the structure will crack upon pleted weld will be too brittle to be of any value. cooling and no other means can be used to if a piece of steel, such as an automobile spring, eliminate expansion and contraction forces. } is welded, the heat will remove the springiness Hardening increases the strength of pieces from the metal. Moreover, you must remember after they are fabricated. It is accomplished by that if a weld is made on a hardened structure, heating the steel to some temperature above the the act of welding will usually soften the steel critical point and then cooling it rapidly in air, oil, f and lower its strength. Such metals must then be water, or brine. Only medium, high, and very-i heat treated to restore their original properties. it high-carbon steels can be hardened by this } is evident then, that in welding any alloy steel, an method. The temperature at which the steel must b understanding of the effects of heating and be heate.d varies with the steel used. cooling is important. The tendency of a steel to harden may or may (~ Heat Treating Metals not be desirable depending updn how it is going to be processed. For example, if it is to be Heat treatment is used to soften metal and welded, a strong tendency to harden will make a relieve internal stresses (annealing), harden met-steel brittle and susceptible to cracking during al, and temper metal (to toughen certain parts), the welding process. Special precautions such An ur'derstanding of these processes is impor-as preheating and a very careful control of heat tant to a welder becausa often he must be aware input and cooling will be necessary to minimize of how welding heat will affect the structure this condition. During welding, an extremely which he is welding. high localized temperature difference exists be-( Annealing is a softeriing process which allows tween the molten metal of the weld and the metal j metal to be more readily machined and also being welded. The cold parent metal acts as a eliminates stresses in metal after it has been quench to the weld metal and the metal nearby welded. The steel is heated to a certain tempera-which has been heated above the upper critical ture and held at this temperature to allow the temperature (the metal's temperature of trans-carbon to become evenly dis +ributed throughout formation). The resulting structure of these the steel. The degree of annealing temp'erature areas is t.ard, brittle martensite. The greater the varies with different kinds of steel. After the harderubility of a steel, the less severe the rate { metal has been heated for a sufficient period, it is of heat extraction necessary to cause it to hard-l allowed to cool slowly either in the furnace or by en. This is one of the reasons that alloy and burying it in ashes, lime, or in some other insu-high-carbon steels have to be welded with i lating material. greater care than ordinary low-carbon steels. i i tV

~ mn 1 ATTACHMENT B Welding Metallurgy 25 Case Hardening you know the strength properties of a metal,you can build a structure that is safe and sound. Case hardening is a process of hardeHing Likewise, when a welder knows the strength of h low-carbon or mild steels by addinn carbon, his weld as compared with the base metal, he O nitrogen, or a combination of carbon and nitro-can produce a weldment that is strong enough . gen to the outer surface, forming a hard, thin to do the job. Hence strength is the ability of a outer shell. The three principal case hardening metal to withstand loads (forces) without break-techniques are known as carburizing, cyaniding, ing down. and nitriding. Carburizing consists of heating low-carbon steel in a furnace containing a gas atmosphere with the desired amount of carbon monoxide. An alternate method is to heat the steel in contact with a carbon i..aterial such as charcoal, coal, N[d.,,. N ENd h. h i I ? nuts, beans, bone, leather or a combination of [dh IN k!!h3). -$ f these. However, modern methods of carburizing

. [,

.'] /~h; [ ![. y,',y f u .j y;;.. h use gas atmospheres almost exclusively. 3., k. ' / - The piece is heated to a temperature between ,g.44 [ [ '--( M O / ~ gy~ % s ' 1650* and 1700*F [899* to 927*C] where steel in

.4

./

.f ' t, - [ "[.:,,. [g- .} { ]S j the austenitic condition readily absorbs carbon l on its surface. The length of the heating period c-- depends on the thickness of the hardened case M.[ f j, .} desired. After heating, the steel is quenched, { TC f .) ..l 7 ..j{ [l f f which produces a material with a hard surface - (r }f d and a relatively tough inner core. ~ y . '4 4

• ' ~ - -

2- 'h Cyaniding involves heating a low-carbon steel in sodium cyanide or potassium cyanide. The ff7' j U i ~~"" 7 ( cyanide is heated until it reaches a temperature ,g of 1500'F [815'C] and then the steel is placed in ri e: .f the liquid bath. This produces a very thin outer Q ( -C N - r

• h [h D

l case which is harder than that obtained by the 1< - t NMk carburizing process.

NY b[

'di '

'. 9 h Nitriding is a case hardening method which

(,' (.r p[f produces the hardest surface of any hardening tf process. Hardness is obtained by the formation IN of hard, near. resistant nitrogen compounds in ~ !g M\\ N y? certain alloy steels where distortion must be kept { ' kI.1 } j to a minimum. The alloy is heated to about 900* j-T-w e. 1.: to 1000*F [482* to 538'C] in an atmosphere of k, [g ./ h Q ^ ,. d, / dissociated ammonia gas. N,g . /..- As sy .....; 3 y 2-.y MECHANICAL PROPERTIES OF = S rme.w. --,.'

7. t

m.. L.3"S :i.

.g ,,, y n. - ' METALS a n-Mechanical properties are measures of how y- .{ I 9i'f. materials behave under applied loacs. Another 7, ;'... v y. w. a., '. way of saying this is how strong is a rr etal when it comes in contact with one or more forces. If Fig 3-8. Example of stress and strain.

. ny 1 i ATTACHMENT B 26 Introduction to Welding Some of the basic terms that are associated Modulus of elasticity is the ratio of stress to with mechnical properties of metals are included strain within the elastic limit. The less a material in the paragraphs that follow. A welder should deforms under a given stress the higher the become familiar with them because they are modulus of elasticity. By checking theTnodulus II often directly related to his ability to produce of elasticity the comparative stiffness of different l'a j sound welds. materials can readily be ascertained. Rigidity or H Stress is the internal resistance a material stiffness is very important for many machine and y offers to being deformed and is measured in structural applications. 7p] terms of the applied load over the area. See Fig. Tensile strength is that property which resists g 3-8 top. forces acting to pull the metal apart. See Fig. W Strain is the deformation that results from a 3-10. It is one of the more important factors in stress and is expressed in terms of the amount of the evaluation of a metal. deformation per inch. See Fig. 3-8 bottom. Elasticity is the ability of a metal to return to its original shape after being elongated or distort-ed, when the forces are released. See Fig. 3-9. A rubber band is a good example of what is meant g-by elasticity. If the rubber is stretched, it will M

N

.h/rf, VT J @f' W WC~ f+.. M" E return to its original shape after you let it go. jj However, if the rubber is pulled beyond a certain i point, it will break. Metals with elastic properties j[

1. ~

~ react in the same way. e, Elastic limit is the last point at which a material 4 ~ ~ k6 l 2 l may be stretched and still return to its unde-9- .. 'S F'C ' 0 7.V ".f ' formed condition upon reiease of the stress. f- 'I ~ L 5" r. Y.'. v,5. ' L ' A 6 v .6 lnn Y ?? R'- Q x [L."_ . hl%,;fW c' -* y g. >[ 4 # - R ;. m a i -..J,} M q., y ' ~, Fig. 3-10. A metal with tensile strength resists pulhng forces. y +.ww a ; u,,., + 4-M MMM + ~%m 9 .c e.g

e gj

-r /' Compressive strength is the ability of a materi-g 7 a/@ f[

• f) 47 al to resist being crushed. See Fig. 3-11. Com-5

[ pression is the opposite of tension with respect f g g a 7 gfj ~~

E 1

to the direction of the applied load. Most metals 3 i have high tensile strength and high compressive q~ g I-( .[ M.) strength. However, brittle materials such as cast ,g

Q*

iron have high compressive strength but only moderate tensile strength. [ Bending strength is that quality which resists q j { forces from causing a member to bend or deflect [ g in the direction in which the load is applied. ..s_ Actually a bending stress is a combination of j Fig. 3-9. A rnetal having elastic properties returns to its tensile and Compressive stresses. See Fig. 3-12 g original snape after the load is removed. top to grasp the idea. g l l l l

. cuar 4 ATTACHMENT B i Welding Metallurgy 27 j ,i d } [Ai$$ 3 i !Ph - ,) 3 + f 7 ; f '-f 1 7 g, N ,3 l [ me fb-Men [ %p 2,a Y D A s.. %~~ - g ~ . a., g W4 p - s m C HNstON i c Y 4 3 V

ZE T

@2.@ ;&Oj$EG-M y 9y Jc; W.Qg;g' g%*ed:,;i,g pd;%h y@v.y y e5 jf d:.C:: -t e& fy;.,t m 4,v mung +s y w . 41;fh[ se 1 sasumreo. g ' f, e 9 h b f k t.... J.? pi Eygd d, A! 4 tw[43 ". a m, j g i q wm 'k 2 ' MJ C7 M rukub h f s-y -er, p 1 L Fig. 3-11. Compressive strength refers to the property of ~ 'Njf.f ~, j -M i )! La +IT 3t~} g ': e metal to resist crushing forces. t 5 i, p ? mn 4[d.k l E j Ud*Id I. ..i l 'A89~ Torsional strength is the ability of a metal to withstand forces that cause a member to twist. ' ;E.,4 *$A m$;5vGi)tf4+~f.:4g Af ?33:' > @S w ; .g Fpy-m wn %, rr w w t w.,y r.w. a,_ +,o. 3 y 6 p~ See Fig. 3-12 middle. - e, w ..s ' l' s < d Vt + % > - Mh ' N d t;,g.Jf.qj";p'ggyg.N.-vonsglONp e Shear strength refers to how well a member jpt g-r. y qv .o. yg

g jggg'.

can withstand two equal forces acting in oppo-i g '- ~3 site directions. See Fig. 3-12 bottom. g-pgg., 4 Fatigue strength is the property of a material y to resist various kinds of rapidly alternating Q ,l j i l stresses. For example, a piston rod or an axle [ undergoes complete reversal of stresses from u ' ~ y J tension to compres; ion. b g Impact strength s the ability of a metal to

gf yk&

resist loads that are applied suddenly and often pc(edy 4:p * ] at high velocity. The higher the impact strength ~ ,,gg ( of a metal the greater the energy required.to. 4 gg e,g 'gyK, y break it. Impact strength may be seriously affec't-jQ!g5 3. ed by welding since it is one of the most struc-g ture sensitive properties.

1. • W

_1 s Ductility refers to the ability of metal to stretch, h,%w MWTMhMSkik bend, or twist without breaking or cracking. See Ij Fig. 3-13. A metal having high ductility, such as Fig. 3-12. Examples of bending. torsion, and of shearing copper or soft iron, will fail or break gradually as stresses. t I r'>

I ATTACHMENT B d 28 Introduction to Welding L .d an indentation made by a special ball under a l standard load, or the depth of a specialindenter Q under a specific load. t' l Britt/eness is a condition whereby a metal will j easily fracture under low stress. It is a property

~l

.g q rM ,.gp wisich often develops because of improper weld- [ b h @[ N ing techniques. Brittleness is a complete lack of k t g,. [ It8) ductility. . r,. ; - -

• M

[, Toughness may be considered as. strength, ,3 together with ductility. A tough material or weld 1,r. is one which may absorb large amounts of ener-j, gy without breaking. It is found in metals which ,l [ exhibit a high elastic limit and good ductility. Welding materials of this kind must be done with a great deal of care. For example, improper application of heat may change the grain size and carbon distribution in the metal so its inher-ent toughness will be completely destroyed. Fig. 3-13. A ductile rnetal can easify be shaped. Md//eability is the ability of a metal to be .] L deformed by compression forces without devel-oping defects, such as encountered in rolling, pressing, or forging. Creep is a slow but progressiveiy increasing strain, usually at high temperatures, causing the metal to fail. j((pg\\ hv Cryogenic properties of metals represent be-( havior characteristics under stress in environ-G 'Qfy. e ? 4* ments of very low temperatures. In addition to %@ppg h y ;p, being sensitive to crystal structure and process-J e S.- a w.

[W/ -

ing conditions, metals are also sensitive to low /2 -t . h." 4./ and high temperatures. Some alloys which per- [, J form satisfactorily at room temperatures may fail . 4~;. k gg% ' ccmpletely at low or high temperatures. The f% D 4 changes from ductile to brittle failure occurs rather suddenly at low temperatures. L ' * *St" % ~ ?" Coefficient of expa'sion is the amount of ex-A " ^ " ' ' " ' " " * ' " " " " * ' 'a' d" p M$ bhh:td ' p2ON@ljpJQ, $$s_AS:sEb h temperature rise of 1*F. The expansion rate of WMT9fh? metals is always an important factor in welding. Fig. 3-14. Hardness resists penetration. .\\'. ~ CLASSIFICATION OF CARBON the load on it is increased. A metal of low STEELS ductility, such as cast iron, fails suddenly by cracking when subjected to a heavy load. A plain carbon steel is one in which carbon is Hardness is that property in steel which resists indentation or penetration. See Fig. 3-14. Hard-the only alloying element. The amount of carbon ness is usually expressed in terms of the area of in the steel controls its hardness, strength, and ductility. The higher the carbon content, the h.

.n - mc y .'2-a I ATTACHMENT B n._ er. l Welding Metallurgy 31 D. Series Examples: q ' )'g' Type of Steel Designation C1078-Basic open-hearth carbon steel; car-Carbon steels. 1XXX bon 0.72 to 0.85 percent Plain carbon ... 10XX E50100---Electric furnace chtomium steel 0.40 Free machining. resulfurized (screw to 0.60 percent; chromium,0.95 to 1.10 percent stock) 11XX carbon. Free machining, E2512-Electric furnace nickel steel, 4.75 to resulfurized, rephosphorized 12XX 5.25 percent nickel: 0.09 to 0.14 percent carbon. Manganese steels. 13XX High-manganese carburizing steels 15XX Nickel steels. 2XXX 3.50 percent nickel. 23XX WELDING DEFECTS 5.00 percent nickel. 25XX Nickel-chromium steels. 3XXX in the process of welding various materials, 1.25 percent nickel, precautions must be taken to prevent the devel-0.60 percent chromium.. 31XX opment of certain defects in the weld metal 1.75 percent nickel, otherwise these defects will severely weaken the 1.00 percent chromium. 32XX weld. The following are some of the principal 3.50 percent nickel, defects that are significant in any welding or 1.50 percent chromium. 33XX brazing process. Corrosion and heat resisting steels. 30XXX Grain growth. A wide temperature differen-Molybdenum steels. 4XXX tial will exist between the molten metal of the Carbon-molybdenum. 40XX actual weld and the edges of the heat-affected Chromium-molybdenum .41XX zone of the base metal. This temperature may Chromium-nickel-molybdenum . 43XX range trom a point far above the critical temper-Nickel-molybdenum. 46XX and 48XX ature down to an area unaffected by the heat. Chromium steels....... . 5XXX Thus the grain size can be expected to be large Low chromium. . 51XX at the molten zone of the weld puddle and Medium chromium.. 52XXX gradually reducing in size until recrystallization Corrosion and heat resisting. 51XXX is reached. Grain growth can be kept to a mini-Chromium-vanadium steels. 6XXX mum by effective control of preheating and post-Chromium 1.0 percent.. 61XX heating. Nickel-chromium-molybdenum... 86XX and Where heavy sections require successive 87XX passes, it is-possible to use the heat of each Manganese-silicon... .. 92XX successive pass to refine the grain of the previ-Nickel-chromium-molybdenum.... .93XX ous pass. This can be done o'nly if the metal is Manganese-nickel-chromium-allowed to c7ol below the lower critical tempera-molybdenum. .94XX ture between each pass. High-carbon and alloy Nickel-chromium-molybdenum. ... 97XX steels are especially vulnerable to coarse growth Nickel-chromium-molybdenum..... 98XX if cooled rapidly. These metals usually require a Boron (0.0005% boron minimum)....XXBXX certain amount of preheating before welding l AISI also uses a prefix to indicate the; steel-and then allowed to cool slowly after the weld is making process. These prefixes are:. completed.,_ A-Open-hearth alloy steel r Blowholes. Blowholes are cavities caused by B-Acid Bessemer carbon steel gas entrapment during the solidification of the C-Basic open-hearth carbon steel weld metal. They usually develop because of D-Acid open-hearth carbon steel improper manipulation of the electrode and fail-E-Electric furnace steel of both carbon and ure to maintain the molten pool long enough to alloy steels float out the entrapped gas, slag, and other e

^ . - -.,,-, m -.. ,c r ATTACHMENT B i I 32 Introduction to Welding- [1 foreign matter. When gas and other matter be-Unless an adequate protective shield is provided O come trapped in the grains of the solid metal, over the molten metal, gas will enter the metal $~' small holes are left in the weld after the metal and weaken it. l} cools. Blowho!es can be avoided by keeping the molten pool at a uniform temperature through-RESIDUAL STRESSES. t out the welding operation. This can be done by using a constant welding speed so the metal The strength of a welded joint depends a great J solidifies evenly. Blowholes are most likely to deal on the way you control the expansion and l ) occur during the stopping and starting of the contraction of the metal during the welding weld along the seam, especially when tl e elec-operation. Whenever heat is applied to a piece of trode must be changed. metal, expansicn forces are created which tend /nclusions. Inclusions are impurities or for-to change the dimensions of the piece. Upon eign substances which are forced in a molten cooling, the met 31 undergoes a change again as puddle during the welding process. Any inclu-it attempts to resume its original shape. sion tends to weaken a weld because it has the No serious consideration is given these factors same effects as a crack. A typical example of an when there are no restricting forces to prevent inclusion is slag which normally forms over a the free movements of the expansion and con-deposited weld. If the electrode is not manipulat-traction forces or when welding ductile metal, ed correctly, the force of the arc causes some of because the flow of metal will usually relieve the the slag particles to be blown into the molten stressas. When free movement is restricted there pool. When the molten metal freezes before is likely to occur a warping or distortion if the these inclusions can float to the top, they be-metal is malleable or ductile, and a fracture if the come lodged in the metal, producing a defective metal is brittle, as with cast iron. weld. To better understand the effects of expansion inclusions are more likely to occur in overhead and contraction, assume that the bar shown in ws' ding, since the tendency is not to keep the Fig. 3-16 is thoroughly and uniformly heated. molten pool too long to prevent it from dripping Since the bar is not restricted in its movements, i off the seam. However,if the electrode is manip-ulated correctly and the right electrodes are used with proper current settings, inclusion can be avoided, or at least kept to a minimum. ( Segregation. Segregation is a condition QgQ .m l .g;... u where some regions of the metal are enriched I-M 3 M.. Q. w %g ( (gf g ]W?;/ d QF M M C % 5h"y Q g f, Q jj with an alloy ingredient while surrounding areas -4 Qes Q n --w r are actually impoverished. For example, when w p,f p.); y. s. gg gg metal begins to solidify, tiny crystals form along y4, j/ y,,y;. grain boundaries. These so-called crystals or i y '; 'f f pM. dendrites tend to exclude alloying elements. As

j. y ff

), I other crystals form, they become progressively .g' richer in alloying elements leaving other. regions g;h ' without the benefits of the alloying ingredients. [lO kb g x. 'WV-Segregation can be remedied by proper heat treating or slow cooling. f y j.yf g fg g g SNS.N N bomb " "" ~ ' " ' ' " ' "h f M[ M Y )' ' '" Foros/ty. Porosity refers to the formation of M h,M M tiny pinholes generated by atmospneric contam-ination. Some metals have a high affinity for W oxygen and nitrogen when in a molten state. Fig. 3-16. This is what happens when a bar is heated.

E3MMERWh?. 7.: e. .. T.mammmmm-l !h ATTACHMENT B !Ng g Welding AfetallUrgy 33 v s g %. J y w 1 c,. V 'j H

.,~ ;,:ny g n.-.w g.

q@yQ hh&= N,$14 s c. > m s q,, %f- ' Q.. y c$.W-7if M %.g-p% M C ~ ' ?g.ly h,/ G ..M'ay Q. r 3 u +, p 3 Nc z w_ w'.in s..: p-. N sw y a ,w[. d s

• .ig a f-i :;.Ja &

e p Q,,; )@ N' 8 h w...'. [ y((, c p. b.h4[ L-w -- .d'Nkh5.NT M k' A A w i'" kIh5. Nfd

f. U,, - [M;Mk{*(i; Nk.']_ '.

$ h fhI ky d h djy ut '_I. '.. k$'27 I h;h[#e.- k M*. ~~ <[T - 5 m- . ;a),N.C m 's-e% t f v. N6fNYgM(2F k... [ ', ' " y %M f _/ ~ -- - > - - - - -. _ ~ .u _ i /

; 3-C Tre encars ce f:rces are %ncered Arer tne bar has restrictir.; f orces l+e this.

expansion is free to tase ciace in all d:rections. e d> Consequently tne overan size of tne bar is in-r

...c y' T.4 i

..,%:.;.. y.... . 3. o #c, _"? d @.--~...h, Gl y, $') $g,<let.-3// g.- .w - jgc ej creased. If the bar is aHowed to coof without !Se ,w ::n 4 - restraint cf any kind,it wdi contract to its origtnal wgr{' - sn. y,; ,1 snaca s. Supcose now that a similar Car is clamped in a v:se. as snown in Fig. 3-E and neated Be-g 3,q g3 3,ece has been distorted because encans'on terces we e res:r.cted cause tne encs of the car cannot move. expan-s,on must ta<e place m anotrer direction. In tnis case ine exoansion occurs at the sides. If heat is applied to one section only, the expansion occomes uneven. The surrounding cold metal prevents free expansion and the dis-clacement of metal takes place only in the heat-ed area. Wnen tnis area starts to cool. Contrac-tion wdl a!so De uneven and some of the original ever hmits it desires. When the piece begins to disclaced metal will become permanently dis-cool, there are still no forces to prevent the metal from assuming its original shape. torted as illustrated in Fig. 3-18. Suppose the break was in a center section as To snow just how the expansion and contrac-i tion forces affect metal. study the results of shown in Fig 3-20. Note that in this case the ands of the bar are rigidly fastened to a solid welding two different pieces In the first case, frame. If the same procedure is used to weld the ) 1 assume a break has occurred in the middle of a fracture as in the first case, something is bound j bar, as m Fig. 3-19. Upon welding tne break, the heat naturally will cause the metal to expand. to happen to the casting if no provisions are Since there are no obstructions on the ends of made for expansion and contraction. Since the the bar the metal is permitted to move to what-vertical and horizontal sections (outside) of ) b

,.b ATTACHMENT B j 34 Introduction to Welding ,i s s m n.Y*

.z p.:

s cs c.~w-a,51 pU @ e eG 1 -{y/@% p(. .;4h.Ri .r fy m'fy M.' Fig. 3-19. In welding this break, expansion forces are free to s 1 x - i?.i?^ d 2lidh$Y; move as heating and cooiing occur. C'QQ - }ff$1M.mll} '

1. 3 7.),- c

{ A.. I A, ) 3 m., m.w . ~,. - - w? ..&. ~' _,4 u... f.Q.a..y : n ::rb w u b. K% U .y .e 4 - dl% N yb ~ M Q+ :;P c "' + ~

,q.

s ...t .' ' :;LL H 'T (-' A' rt ~'Q' " i y; $-; r. ' :TI}7TT', - i

• D x..

-. >[ 4. d2'i' E p$3., . q.a -

• %[k'N[h[ l c.$f@g

} d s.- 'L T Qijh_ *, YS" I'y l( ^^ . J.; "'UN. f dk% ' y "' cJp 1 -W:g%p. .g % : l -Qg yd ~%. ~,, . L 741 f jp a .-{ . n E? '.l.h^ j r y. 2 ~ .g . v. .. a, . i - s' M a h. 5 1.$ 5 v. Fig. 3-20. welding the frame in this confined portion will cause the frame to crack. the frame will prevent expanding the ends of the center piece, there is only one direction in which Controlling Residual Stresses this movement can go while the metal is being heated. That is at the point where fusion takes The following are a few simple procedures place. Now consider what will happen'when the which will help control the forces caused by I section begins to cool. The frame around the expansion and contraction: I center section has not moved and, when con-Proper edge preparation and fit-up. Make traction sets in, the center piece will be short-certain that the edges are correctly beveled. ened. When the rigid frame resists this pull, a Proper edge beveling will not only restrict the fracture or deformation at the line of weld or in effects of distortion but will insure good weld some other place is bound to occur, penetration. See Fig. 3-21. Although sometimes the bevel angle can be reduced, care must be 1 t .1 _.pemm. _ _ _ _ - - - - - ~ - - -

c.- . = .4 i.' , g -- a. ATTACHMENT B l' Welding Metallurgy 35 }i.

x r""~ "WW]p1*- f7.p*x55Q*'lfA%**ycTW NEUTRA'L AXIS 5[

[ wtLO NIAR NEUTRAL AXIS b 4 t / [ g q, w s,- c p t r. 7 h [

• S h

\\ d I- = emm.p$(y$ tDM*I pai,m.z,7,,. w n, iV 5'4yj - 2 QQfG%%P:?? ? ~ f Nks

.r. t.d N;/c'$DMPMNME '

\\ \\ / I _/s w -w. w - 7, w. - + 3,. 'f _~3.. .. ~ ,e ) s t. ( \\ Lt55 Dl5T0RTION l NEUTRAL AXIS . g{t.. y 773 ( Q lD;,A. ~'?f 1 ROOT & 'I h' %. l%lQin.,Y, y &&Y .$ $ &+.^-l[tN'!F D ' b W@ f',4 3 f.atDUCE SIVIL ANGLE WITH LARGE ROOT OPINING M,Y N* I -ea m. 4,- y N e-..ew.~ - a. .. m 5% ( r-b N.,Wh.a$$e S.&v,.$.&?NWi$$$, n.N

• 5 t

n r n- .. & A ;+ - r ^ ,_ yh* * *T Ylh re:Ahc%.,,N QL) & l + a g< (.-4,%. C. 4.. W---/ Ln I 1

4. y:C.

.p' : Fig. 3-22. Weiding near the neutral axis helps to reduce 6 i I.M*C { CG, distortion. w,.~ > w, M s T4 I; & Q hv b! E l f:^ \\ l. E. S ki'bi h $,/8"f0REACM Z.*Y khr'. Y fiv - d ?h-b. W ~~- ALLOW id ,Qi;-;.g.

l '. f.-J FOOT Of LINGTMy *}

M M[s r-g -~ N O.,9,;;d,r//i.X Q.<+cy. 4 -[% lf.,"f-d tl(p$.[... ^* ZP w.A ' e . wj g e g ~ - + f _-I,'{Jd j f 4 -~ mn x~ r p. ~ ny USE DOUBLE.V 8N PRtitRENCE TO SINGLt.V ON

1 ", W THICK $1CTIONS

~ .j; ; Fig 3-21. Proper edge-preparation will mirurnize distortion. r"7' ..a,. T &i M. %;ctr.q%. 7

• s Slik$d@9Fi$I[

WM taken to insure that there is sufficient room in the 1.9.* rsodiX.If.W. - 2

• eski I joint to permit proper manipulation of the elec-

- x hM:. rt'.' trode when doing the weld. J

A

.c Y Less distortron will occur if the welds are i -

e.:-

'F 5+ b balanced around the center of gravity which is n _.. '

e <*~signated as the neutral axis. See Fig. 3-22 top.t Fig. 3-23. Provide a space between the edges to be welded. left. Furthermore, distortion is reduced ~ if the joint nearest to the neutral axis is welded first, followed by welding the unit that is farthest frorn the neutral axis, Fig. 3-22 top, right, for each foot in length of the weld for expansion. and bottom. See Fig. 3-23 for exarnple. On long seams, especially on thin sections, the Tack welds are also used to control expansion practice is to allow about %" [0.125"] at the end on long seams as shown in Fig. 3-24. Tack welds

.7 N 'm - + $. W lug y ppr 4 .t g.. - j g.,. ATTACHMENT B 36 Introduction to Welding f i / t. I; hI w.e a [.

• i %(7 -

Fig. 3-24. Tacking the plates will hold them in pcsition. nf 3 '?+ ,f ' 1 l %*x h- }m.1 L = i Q._ e :S. = k / t Fig. 3-25. Weld long longituoinal seam first. ihl$ +.Y"^~ $2; ' LONG sfAM g N?-d i.c+3 l l are spaced about 12" [305 mm) apart and run weld is made at the beginning of thejoint. Next a l approximately twice as long as the thickness of few inches is welded at the center of the seam, the weld. When tack welds are used, progressive and then a short length is welded at the end of I spacing is not necessary. The plates are simply the joint. Finally you return to where the first spaced an equal amount throughout the seam. weld ended and proceed in the same manner, i Also, a long longitudinal (end-ways) seam is repeating the cycle until the weld is completed. l welded before a short transverse (side-ways) See Fig. 3-26. j seam. See Fig. 3-25. The use of the back-step, or step-back, weld-Minimizing heat input. Controlling 7 the ing method also minimizes distortion. With this amount of heat input is somewhat more difficult technique, instead of laying a continuous bead for the beginner. An experienc.ed welder is able from left to right, you deposit short sections of to join a seam with the minimu n amount of heat the beads from right to left as illustrated in Fig. by rapid welding. 3-27, along the entire seam. A technique often employed te minimize the Preheating. On marty pieces, particularly i ~ heat input is the intermittent, or skip weld. In-alloy steels and cast iron, expansion and con-stead of making one continuous weld, a short traction forces can be better controlled if the [. t

ATTACHMENT B Welding Metallue'gy 37 b lll o. T n .~ s ' : n. \\ .I_. - ~, ,'"*J: d} T - FN r 2. " _ '..'Q - 4 _y:yp .j c ' ..~;. 1;}; J 52-

.l 5j.a.

+:

" Y ~ .s g4 Th ,*-. m ~ {* j i Fig. 3-25. The intermittent weld sometimes referred to as the skip weld, will prevent distortion. ? 6 N s 7 Nh 4 .g' mv 3 N N '~~ 2 ~D \\ N 1 ~m~ k Fig. 3-27. This is how the bacx-step welding technique is done. f entire structure is preheated before the welding with the round end of a ball peen hammer. is started. To be effective, preheating must be However, peening should be done with care I kept uniform throughout the welding operation, because too much hammering will add stresses and after the weld is completed the piece must to the weld or cause the weld to work-harden be allowed to cool slowly. Preheating can be and become brittle. See Fig. 3-28. done with an oxyacetylene cr carbon flame. Stress tellev/ng. A common stress relieving Usually for work of this kind a second operator method is heat treating. The welded component ~ I manipulates the preheating torch, is piaced in a furnace capable of uniform heating Feen /ng. To help a welded joint stretch as it anct temperature control. The metal must be kept i cools, a common practice is to peen it lightly in a soaking temperature until it is heated i j t s 1 l l at m ..i.

ATTACHMENT B I cQ 1 4 f e shielded metal-arc welding GiflPTER II the vertical position 8.q; k In the fabrication of many structures such as POSITION AND MOVEMENT OF THE steel buildings, bridges, tanks, pipelines, ships, ELECTRODE and machinery, the operator must frequently make vertical welds. A vertical weld is one with a Vertical welding is done by depositing beads seam or line of weld running up and down as either in an upward or downward direction, shown in Fig.11-1. (sometimes referred to as uphi// and downhi//) One of the problems of vertical welding is that Downward welding is very practical for gravity tends to pull down the molten metal from welding light gage metal because penetration the electrode and plates being welded. To pre-is shallow, thereby forming an adequate weld vent this from happening, fast-freeze types of without burning through the metal. Morcover, electrodes should be used. Puddle control can downward welding can be performed much also be achiev?d by proper electrode manipula-more rapidly, which is important in production tion and selecting electrodes specifically de-work. Although it is generally recommended signed for vertical position welding. for welding lighter materials it can be used for most metal thicknesses. O gg q r 'y* a .; y ~ f -. y /' J v .n ,j n To 30*, l ,g. yo y 3., / ~N~# gk] s s., u-y D g j ( g l f ..bt .1-Fig.11-1. After tacking the rnetal strips together, this opera. Fig.11-2. Position of the electrode for downward (left) and tor lays vertical welds. (Hooart Brothers Co.) upward (right) vertical welding. 114 W

ATTACHMENT B The VehicalPosition 115 - ~~----:,--.. 1 On heavy plates of 1// or more in thickness, Laying Straight Beads in a Vertical upward welding is often more practical, since Position-Uphill Method deeper penetration can be obtained.. Weiding

1. Obtain a '// plate and draw a series of uoward also makes it possible to create a shelf straight lines. Then fasten the piece so the lines for successive layers of beads. -

are in a vertical position. For downward welding, tip the electrode as in

2. Strike the arc on the bottom of the plate. As Fig.11-2 left. Start at the top of the seam and the metal is deposited, move the tip of the move downward with little or no weaving mo-electrode upward in a rocking motion as shown tion. If a slight weave is necessary, swing the in Fig.11-4. This is often called a whipping electrode so the crescent is at the top.

motion. In rocking the electrode, do not break j For upward welding, start with the electrode it right angles to the plates. Then, lower the rear of the electrode, keeping the tip in place, until the gg p7 - p.-ggy l electrode forms an angle of 10*-15* with the 3y 3, t norizontal as shown in Fig.11-2 right. j[ p q l l db9.5' "n MwM l m 4 Laying Straight Beads in Vertical-Downhill d ~~ D-bOh. ', @J. ?..h[ ' Method r & 2 d [w k.3 %{; f Set up a practice piece in a vertical position jbg NQ y .p__ with a series of straight lines drawn on it. Start at t.jg

* (ju-ec s _..,,

the top of the plate with the electrode pointed g ~ upward about 60* from the vertical plate. Keep [. q the arc short and draw the electrode downward ,:f fg/jgy s w { to form the bead. Travel just fast enough to keep 4 -y y My M ; ' gy.y the molten metal and slag from running ahead of s- ' d W "'E $;) 1 4 - - the crater. Do not use any Weaving motion to A start with. Once this technique is mastered try u hill eld ng y weaving the electrode but very slightly with the crest at the top of the crater. See Fig.11-3. t L.. Y the arc but simply pivot it with a wrist movemont 3 so the arc is moved up ahead of the weld long 4 ga enough for the bead to solidify. Then return it to [ the crater and repeat the operation, working up N [ E. along the line to the top of the plate. Remember, r ? l'[ k {l: do not break the arc while moving the electrode Y( p {#Q upward. Withdraw it just long enough to permit .. M 6,C { 7:7 ', MMW,. f 4 the deposited metal to soHdify and form a shelf ..k' ch IN so additional metal can be deposited. Continue a i %w A n;bp, ** to lay beads from bottom to top unti: each line is i

M,n W4,r i

y p +-

1. ;.q r:a smooth and uniform in width.

Laying Vertical Beads with a Wr aving Motion p p On many vertical seams in uunill welding it is i sownwrtt witDino wiTH DowNHitL WatDiNo WirH necessary to for,m bedds of Virious Widths. The no weava motion strowr weava motion width of the bead can be cor. rolled by using one . Fig.11-3. Downhill weiding rnethods. of the weaving patterns she wn in Fig.11-5. Each h /6) -}}