ML19324B270

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Forwards Rept on Metallurgical Evaluation of Five Bolts Obtained from Farley Plant.Bolts Found Acceptable
ML19324B270
Person / Time
Site: Farley, 05000000
Issue date: 03/02/1988
From: Taylor J
BROOKHAVEN NATIONAL LABORATORY
To: Conway J
Office of Nuclear Reactor Regulation
Shared Package
ML19324A112 List:
References
CON-FIN-A-3866, FOIA-89-334, FOIA-89-335, FOIA-89-336, FOIA-89-337 NUDOCS 8911030029
Download: ML19324B270 (18)
v • d • e


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BROOKHAVEN NATIONAL LABORATORY t;f Q (ll ASSOCIATED; UNIVERSITIES,ilNC.":

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- Upton, Long Islond. NewYork 11973

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.b Department of Nucleor Energy; FTS 666' 7005

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-1 Building 130 e

March 2, 1988 7

Mr." James Conway; U.S. Nuclear Regulatory Commission i

Vendor Programs Branch Mail'Stop 9D4 Washington, DC-20555 ay Reft Testing of Farley Bolting Materials, Fin A-3866, Task Asuignment 9

. Dear Jim L

h n.

f.

Enclosed is four copies of a report on the metallurgical evaluation of five bolts that had been obtained from the Farley plant and tested by C.J. Czajkowski of BNL. These five bolts (S0-18 through S0-21'and S0-23) had originally been 'out a

y of specification after the' original tensile and chemical testing.

The results of the testing are S0-18 Exceeded chromium level and had below maximum carbon level.

(Notes insuf ficient carbon level was inadvert.ently not identified in the pre-vious report.). This bolt is considered " suitable for service" after reevaluation and examination.

t

' SO-19 :

Exceeded chromium levels. The.s bolts are consi<iered "suiuble for

~ Through-service" after reevaluation and examination.

S0-21 S0-23:

Exceeded maximum hardaess. This bolt is considered acceptable af ter retesting in accordance with ASTM A370-77.

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If there are any questions, please feel free to call.

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Very truly yours, "f87, r

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, John H. Taylor, Group Leader Encl.

Plant Systems & Equipment Analysis j.

cc:

E. Baker, NR C. Czajkowski B. Grenier, NRC R. Hall W. Kato W.1 Shier J. Stone, NRC

' File 8911030029 891030 PDR FOIA g/r/

MCGRATH89-334 PDR 3

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BROOKHAVEN, NATIONAL ~ LABORATORY.

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,b,I MEMORANDUM

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oArt:

March 1,1980 en i

To:

John Taylor M

W

/

42 FROM:

C.J.'CZajkowski(FTS 666-4420) m<

. suancT Retesting' of Bolts S0-19 through S0-2 and S0-23 for USNRC I,

l&

Pursuant with Task Order No. 9 under FIN A-3866, please find attached copies of metallurgical evaluations for bolts identified as S0-18 through S0-21 and S0-23.

These bolts had previously been found (nty memo to you 10/20/87) to be out of specification after the original tensile and chemical i

testing.

The-results of the retesting are:

S0-18:

Exceeded chromium level and had below maximum carbon level.

(Note:

insufficient carbon level was inadvertently not identified in 10/30/87 report.) This bolt is considered " suitable for service" i

t after reevaluation and examination.

S0-19 thrugh S0-21: ' Exceeded chromium levels. These bolts are con-sidered " suitable for service" after reevaluation and examination.

r S0-23:. Exceeded maximum hardness.

T,is bolt is considered accept-able after retesting in accordance with ASTM A370-77.

h;?

This completer Task 9.under FIN ' A-3866.

Four additional copies of the d'

. report are attached for transmittal to the NRC.

If there are any quest 9ons, N

please contact me at the above number.

CJC/ts

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. Attachments fSh

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L M. Schuster W. Shier i'

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.80LT SPECIFICATION:'; A193-87 L

+

BOLT IDENTIFICATION:.50-13l O

(:t -

".,,'1 h:.

]

7 n

BOLT SIZE:

3/4 - 10 UNC Q;

4 wr TENSILE STRENGTH:

I 1

Actual Required by Specification e

f 142.22 ksi

'125 ksi (min.)'

(~

i.

[

Failure Location - Threads c

' HARDNESS:

Actual Required by Specification 59.16 R Not Required:

A CHEMICAi. ' ANALYSIS:

Actual w/o Required by Specification w/o t

Carb'on 0.34 (Note 2) 0.37 - 0.49 1' ~

Manganese 0.96 0.65 - 1.10 i '4 "

l.i Phosphorus 0.12 0.035 max

. Sulfur 0.006 0.040 reax n

Silicon 0.28 0.15 - 0.35

' Nickel 1,

1.55 (fbte 1) 0.75 - 1.20 Chromium 0.06 E

Molybdenum 0.19 0.15 - 0.25 (0

Vanadt um

<0.05 1;.

4L iColumbium + Tantalum

<0.05 U

L 3 '.

y, j$ i L

< = Less than

,a 1,'

r C0i9 TENTS:

1) Chromium value exceeds specification requirements even factoring in pennissible variations (0.05% over). 2) Carbon content below minimum level L

after factoring permissible variation. Note:

inadvertently not identified on original 10/30/87 report.

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,J METALLURGICAL EVALUATION y;

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f' BOL7 IDENTIFICATION: S0-18 BOLT SPECIFICATION: ' A193-B7

.f.

1

~,

' BOLT' SIZE:

3/4 10 UNC s

Wh ;

% [. f '!

Methodology:

4 1.

A section was cut from the boh, mounted in epoxy, then metallurgically l

ground, polished and etched (2% Nial).

The section showed (Figure 1) a 3,!

tempered martensite microstructure consistent with this type of material.

il r

2.

Half _ of the fracture face (after tensile testing) was-examined under the scanning election microscope (SEM) (Figure 2).

The resulting fractograph A,.

showed a _ dimpled rupture appearance which indicated good ductility in the "i <'

fracture.

m

==

Conclusions:==

Ti : bolt is considered to be suitable for service for the following reasons:

~

1.

The polished section showed a microstructure consistent for this grade of bolt.

The SEM examination revealed that the fracture (after tensile testing) was' ductile in nature.

This coupled with the fact that the bolt

-j 4

met the tensile requirements of A193-B7 material and was only 0.01% below the minimum carbon level and 0.35% above the maximum chromium level (all other chemical requirements were met) leads one to believe that the ten-W sile requirements will not be a problem for this bolt.

The only other

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major consideration would be if the bo?t could fail in a brittle (as opposed to ductile) manner in service (Notch Toughness) due to these chem-l ical composition variances,

.de L

The Metals Handbook, 8th Eoition. Vol.

1.

Properties and Selection of PI%

l Metals, defined Notch Tdughness as::

e,

...the ability of a metal to yield plastically under high

?

localized stress, such as might occur at the root of a notch...

4pf*'

L This measure of a material's property would be very applicable to C

j i

fasteners.

4 u

l Carbon Content I

.t.

l This same reference mentions that as carbon content is raised in the range.

c from 0.15 to 0.80% in normalized plain carbon steels, the notch tonghness L

decreases- (at room temperature).

This lowering of energy absorption is

s. y accompanied by a subsequent raising of the transition tamperature (6*F per ds 0.01% increase in carbon content above 0,30% carbon).

The net effect of this lower amount of carbon on this particular bolt would then be to r

i increase the amount of energy absorbed and decrease the transition temper-

~

ature as much as 6'F.

Both of which should be beneficial to the bolt's

" suitability for service."

1

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BOLT IDENTIFICATION: 50-18 BOLT SPECIFICATION: A193-B7 9

94 a

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. BOLT SIZE:

3/4 - 10 UNC W '

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Chromium Content-

~

.at,o The Metals Handbook, 8th Edition,.Vol. '1, Properties and Selection of Metals, states:

" Chromium has slight effect on transition temperature..."

- i Since the impact properties should not be sigr.ificantly impaired due to the

. higher chromium content, the bolt is considered " suitable for service."-

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Figure 1 Optical photomicrograph c tempered Figure 2 SEM fractograph of S0-18 showing p$:

martensite s :ructure of P -18 (400X).

ductile failure (1000X).

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BOLT IDENTIFICATION:' S0-19

. BOLT SPECIFICATION:, A193,87.. ; :..

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K.

t SOLT SIZE:,

1" -. 8 UNC L.

? :; L s a

,.3

.r

,(

TENSILE-STRENGTH:

'T Actual Required by Specification

~

.u 143.03 ksi 125 ksi (min.).

t Failure Location - Shoulder i

r HARDNESS:

t Actual Required by Specification l

27.6 R Not Required C

j i
F CHEMICAL APALYSIS

,E Actual w/o Required by Specification w/o o'

Carbon.

-0.40 9.37 - 0.49

?

Hanganese-0.98 0.65 - 1.10 Phosphorus' O.005

' O.035 max W_

Sulfur.

0.016 0.040 max Silicon 0.21 0.15 - 0.35'

~

Ch romium 1.80 (No,te 1) 0.75 - 1,90

. NIcr el 0.34 r.

Molybdenum 0.19 0.15 - 0.25 ii ;

Vanadium

<0.05 l Columbium + Tantalum s0.05 OT '

sg4.t

. ~,

e

'N4-(

< = Less than

.u se.

gg a.

3,,fA '

a COPMENTS:

1) Chromium value exceeds specification requirements even factoring l -

n ' i in permissible variations (0.05% over)

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METALLURGICAL'EVALUATIONL

7. '..

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u t

. '.5 BOLT. IDENTIF.ICATION:

S0-19 BrLT SPECIFICATION: A193-B7

^

A +,

BOLT SIIE:

1"- 8 UNC y

l:p Methodology:

Y 1.

A section was cut from the bolt, mounted in epoxy, then metallurgically ground, polished and etched (2% Nital).

The section showed (Figure 3) a p+

tempered martensite microstructure consistent with this type of material.

+

2.

Half of the fracture face (after tensile testing) was examined under the Z

scanning election microscope (SEM) (Figure'1).

The resulting fractograph showed a dimpled rupture appearance which indicated good ductility in the fracture.

==

Conclusions:==

The bolt is considered to'be suitable for. service for the following reasons:

1.

The polished section showcd a microstructure consistent for this grade of bolt.

The SEM examination revealed that the fracture t'after tensile 1

testing) was ductile in nature.

These observations plus the fact that the bolt met the tensile requirements and all of the chemical requirements

.t (except chromium) of the specification leads one to examine the ability of the bolt to resist rapid failure (notch toughness).

Chromium Content The Metals Handbook, 8th Edition, Vol.

1, Properties and Selection of Metals, states:

" Chromium has slight effect on tran ition temperature..."

g!

Since the impact properties should not be significantly impaired due to the higher chromium content, the bolt is considered " suitable for s

service."

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I Figure 3 Optical photomicrograph of tempered Figure 4 SEM fractograph of 50-19~ showingip: !OM$$

,,- 2mm:

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ductile failure '(1000X).

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{ $0 20,

'80LTSPECIFICATI0m/A'193-87:

- l(-

B0LT IDENTIFICATION:

3.

I

-:,q c

BOLT SIZE:

3/8" - 16 UNC 9,

.f,\\

t TENSILE STRENSTH:

i WG Actual Required by Specification' M-151.74 ksi 125 ksi (min.)

. l e

4 Fa11'ure Location - Threads h

7

  • ?

HARDNESS:

g Actual Required'by Specification tg 23.83 R Not Required c

CHEMICAL ANALYSIS:

I f

Actual w/o Required by Specification w/o

,n Carbon 0.41 0.37 - 0.49 1

l-

' Manganese 0.97 0.65 - 1.10

.(f),

Phosphorus

<0.005 0.035 max v;

Sulfur 0.008 0.040 max nl Silicon 0.27 0.15 - 0.35 N-QI.il Chromium 1.51 (Note 1) 075 1S ll,

1. -

Nickel-0.05 Mt j Molybdenum 0.22 0.15 - 0.25 c>;

Vanadium

<0.05

.A I

i Columbium +' Tantalum

<0.05 4

e.dh,

< = Less than f ' l.

.s

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-t C0tWENTS:

1) Chromium value exceeds specification requirements even factoring r,

1 g.

in permissible variations (0.05% over) fi, y

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a.

'h BOLT IDEKIIFICATiON: S0-20 BOLT SPECIFICATION: 'A193-B7 N'

e 4-B0LT SIZE:.

3/8" - 16 UNC a;

Methodolony:

1.

A.section was cut from the bolt, mounted in epoxy, then metallurgically ground, polished and etched (2% Nital).

The section showed (Figure 5) a tempered martensite microstructure consistent ~with this type of material.

2.

Half of the fracture face (after ten:ile testing) was examined under tht scanning election microscope (SEM) (Figure 6).

The resulting fractograph showed a dimpled rupture appearance which indicated good ductility in-the

'(

fracture, t

==

Conclusions:==

The bolt is considered to be suitable for service for the following reascns:

1.

The polished section showed a microstructure consistent for this gra:le of bol t.

The SEM examination revealed that the fracture (after tensile

(

testing)wasductileinnature.

These observations plus the fact that the

~

bolt met the tensile requirements and all of the chemical requirements (except chromium) of the specification leads one to examine the ability of the bolt to. dst rapid failure (notch toughness).

Chromium Content L

The Metals Handbook, 8th Edition, Vol.

1, Properties and Selection of Metals, states:

" Chromium has slight effect on transition temperature..."

E l.

Since the impact properties should not be significantly impaired due to l

the higher chromium content, the bolt is considered " suitable for c

service."

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BOLT'.SPCCIFICATION: JA193,87) >

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r BOLT IDENTIFICATION

.E k.

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j e

. BOLT SIZE:

1/4" - 20 UNC

,u

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r,.

m.

.u;.

~

TENSILE STRENGTHt m,,

Actual Required by Specification

'it

k.

d A

fc 158.80 ksi 125 ksi (min.)'

4'

, Failure Location ~- Threads y.

HARDNESS:

t Actual Required by Specification 62.'6 R Not Required A

CHEMICAL' ANALYSIS:

Required by Specification w/o 4

Actual w/o Carbon 0.41 0.37 - 0.49

. Manganese 0.94 0.65 - 1.10 g

7 Phosphorus 0.020 0.035 max la Sulfur 0.024 0.040 max Silicon 0.27 0.15 - 0.35 l

Chromium

'e 1.4C (f;t,tt.1) 0.75 - 1.20 l

Nickel

' O.47 M<

l Molybdenum-0.23 0.15 - 0.25 f,

Vanadium

<0.05

'i 4

Columbium + Tantalum

<0.05 E>

e-;

- d.

s9

< = Less than 7

l, C0t91ENTS:

1) Chromium value exceeds specification requirements even factoring dk (

o l 'f in permissible variations (0.05% over) 1; L

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l.

1.

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c METALLURGICAL EVALUATION

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(

r DOLT IDENTIFICATION:. S0-21 BOLT SPECIFICATION: 'A193-B7 A

, &r_

S0LT SIZE:

1/4"-20UNC

~

liQ Y

M:

f.

Methodology:

f...;

1.

A section'was cut from the bolt, mounted in epoxy, then metallurgically ground, polished and etched (2% Nital).

The section showed (Figure 7) a

.;j 7

tempered martensite microstructure consistent with this type of material.

~

L 2.

Half'of the fracture face (after tensile testing) was examined under the scanning election microscope (SEM) (Figure 8).

The resultin0 fractograph showed a dimpled rupture appearance which indicated good ductility in the fracture.

I

==

Conclusions:==

The bolt is considered to be suitable for service for the following reasons:

I 1.

The polished section showed a microstructure consistent for this grade of bolt.

The SEM examination revealed that the fracture (after tensile

{

testing)wasductileinnature.

These observations plus the fact that the bolt met' the tensile requirements and all of the chemical requirements (except chromium) of the specification leads one to examine the ability of the bolt to resist rapid failure (notch toughness).

4?gC Chromium Content The Metals Handbook, 8th Edition, Vol.

1, Properties and Selection of l

Metals, states:

A

.a4 1:

" Chromium has slight effect on transition temperature..."

Ls L

Since the impact properties should not be significantly impaired due to 4;.

L the higher chromium content, the bolt is considered " suitable for E

service."

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, / ps y,.4 y.e + r.. .s f ' ' 9 t[k '. 7, n. 'B0LT IDENTIFICATION: $0-23 BOLT SPECIFICATION:,,,A 193-88 '.gjf i g .( m<a f 3. - -,wpy iy + !. g .\\ 30LT SIZE: 5/8" - 11 UNC ff[ ti th .v TENSILE STRENGTH: 'Y l h Actual Required by Specification ~ L

9) i 89.65 ksi 75 ksi (min.)

Failure location - Threads. l ~ n l i [ ., i HARDNESS: ' 1 Actual Required by Specification k 63.6 RA (Note 1) 223HB(max.) 4 (equates to 262 HB) 1 ' I' 0 CHEMICAL ANALYSIS: i Actual w/o Required by Specification w/o q Carbon 0.06 0.08 max 3 Manganese 1.75 2.00 max Ja l Phoschorus 0.050 (Note 2) 0.045 max tf1 Sulfur-0.021 0.030 max V7 ' 2.,, Silicon 0.72 1.00 mn f Cnromium 19 0 18.00'- 20.00 9+ . Nickel 9.0 8.00 - 10.50 L Molybdenum 0.40 M.. Vanadium <0.05 T Columbium + Tantalum <0.05 4A,l ,;;$1 < ' Less than 'i[ .n a ,f.' l %~, a k 1 COMENTS: 1_) Although specification allows a maximum hardness of 241 HB (A193). this bolt exceeds hardness maximum.

2) Permissible variation for phosphorus (0.010% over) by specification allows acceptance of this value.

A

y..
v w q; -

. hy$y%MhNh.h sh . ;)Qpm,f.ihi [h.'ji]fjhfhIf;h;h QM/if,]c;g, -l fN + p n;(U) :

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,

4 , ; g ;. g^yp g,3;,. (. -. ' ;? .1;p m. 8M .s '. i ;x .,: y,' D. ign t o. c o' ,;Y G ' m N e ; ~ 'd g ' ', f'., ' ' J-. , h, s i,. ! ',, [2.m.mp. ',,, " l +'7 " q f, y p, ,'t ! - t c,.. m t5 , j{- F,,. ETALLURGICAL EVALUATION ^ 1 o, (, y. ...w. o :. ~ n: o . - x:, n. '^ BOLT IDENTIFICATION: S0-23 BOLT SPECIFICATION: A193-88 gy t, BOLT SIZE: '5/8" - 11 UNC 4 $lt, E ' Methodology: 4.F U 1. A section was cut from the bolt, mounted in epoxy, then metallurgically 3 ground, polished and etched (electrolytic oxalic acid). The section d showed (Figure 9) an austenitic microstructure consistent with this type gy, of material. y-2. Half of the fracture face (after tensile testing) was examined under the SEM (Figure 10). The resultant fractograph showed a dimpled rupture appearance which indicates good ductility. f, 3. Consistent with the requirements of ASTM A370-77, a transverse section through the bolt was cut and six hardness ' readings taken along the axial . length. E M.'

== Conclusions:== ?k I \\ 1-The bolt is considered to meet specification (ASTM A193-81a) requirements after hardness retesting. The specification requirements allow a maximum hardness of 223HB (with a maximurr hardness of 241HB allowed for 3/4" diameter and smaller bolts), the six hardness retests showed the following hardnesses: g L RB 82, 83, 82, 85, 79, 88.5 j RB. 89.5, equates to 18,1 HB y All of which are below the specification maximum. i h. e e i 4, a E .(7 E l s F

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