ML033350353
| ML033350353 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse  |
| Issue date: | 11/30/2003 |
| From: | Hour K, Hyres J BWXT Services |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| 1140-025-02-24 31-5029337-02 | |
| Download: ML033350353 (53) | |
Text
BWXT SERVICES, INC. 1140-025-02-24 119
- 0,, 1
. 0'. .
Etched.I -O Figure 6.1.1.2: Micrographs showing intergranular attack (IGA) and intergranular or interdendritic cracking on the exposed stainless steel cladding.
BWXT SERVICES, INC. 1140-025-02-24 120 I i :1 . A 0.
As-polished 48X
'I, 4 Anw. Li -
- ? f'p ., J
,.1.,
1'.j'.fp E*
I.. ,., I'**"'
d 5 .....
4
- . . . . ** .,1*
, * .: 1..
C .1 r -.
Etched - .*:::.:....
Figure 6.1.1.3: Micrographs showing the deepest crack observed in A2A7M.
Fine intergranular or interdendritic cracks emanating from the crack tip are visible. The crack tip is estimated to be approximately 0.057" (1.47 mm) below the surface. The cracks in the above two photos are the same, but are shown at slightly different planes due to re-polishing.
BWXT SERVICES, INC. 1140-025-02-24 121
- ~~~~~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~~~ "r
~~~ -~~~e is%:~~~:
~ ~~.~ I ,, , -
375X Figure 6.1.1.4: Typical clad microstructure in the mid-thickness of the cladding.
BWXT SERVICES, INC. 1140-025-02-24 122
(~~~~~ . _.
I OOX XiC-ZnI .
'<Sak ,bh 9 375X Figure 6.1.1.5: Typical clad microstructure near RCS side surface of the cladding. No intergranular attack (IGA) was present.
BWXT SERVICES, INC. 1140-025-02-24 123 rr la lf c r 4 O : , r I. Il 431:C1 C~~~~~~~~~~~~~~~~~C EDSrsultsfor Area i. O Figure 6.1.2.1: SEM micrograph showing the three deepest cracks in A2A7M. Crack tips are 0.042" to 0.069" (1.1 to 1.75 mm) below the surface. It is noted that these three crack tips are at approximately the same distance of 0.199" (5.06 mm) from the underside surface. EDS scans of areas 1, 2, and 3 and line scans 1 and 2 (not included) indicated a generally uniform chemical composition (including Cr content) across the cladding thickness.
BWXT SERVICES, INC. 1140-025-02-24 124 1t 1275-2 Lt.. Lax :~r-J F4t JPXI fl 1 1~'
A.4 X11 ok
- nuTo s- a>c) IC :M.") t ft1 1. C4111 A .
<4 1% c 0 11) 2.O'9 1014 O.)3 L.co4 t, .- UIN -1 N O MI J U*4 tI 'tJ U.474J 1 "44 C. Ca IJS2 -'f % O Jrat>
'J 0;'471 0 r41 1.C4 tW *. 1415 ."%
0ot 3.144; qr.' 0.^'s t.0lCl O tW 3.14 W : ., o.ej -0:24 :C(M J ':, Lr i4Mxn ..
$ 1; .- Rtsfct e )~~~~~~ I 5 10 CTsr=O.OLS !1cV S114 cnt ID =
ert=93-.49 %Window 0.005-40.955 479910c&t EDS results for Area 2.
111 275-J (F L (i LYIC E..* WA A tr " t E,,o2 34*r 4., El I].23nI Wr %I3 fl ow 1 a C...ax C2 I.tWL A .0 CI 0.0?31 0C." I CII C 271M IX104S S. DAM
- G.O14tlC74 It53 C.4'1 t.c4 .
Ct La 1B i4 ^¶% 0.LV4 CURC 0w)y! C34? I 1..t0 M?u.543 t.% 0.204 C.:, O'X W CX55 1.0i3:
t Ks 08 M0.s% 01?1 C:4' ICL'3 C3=9 LcC
.i~ ~~~~~~~~~~~~~~~~~~~~
Ctjr=.;9o.S kV 1 cnt 0.00 ID 5
[Vert-cogs %Vtndowm0.005 40.9S5= 458883 cnt EDS results tor Area 3.
Figure 6.1.2.1 (cont.): EDS results for Areas 2 and 3.
BWXT SERVICES, INC. 1140-025-02-24 125
-. I
' .1 I
- - 1..' 4
- * *' */. v . *I'
.4 ,* *'.r
.i 4
4 (
- A' . * . .. -$
U S ... 36 SI II.,
300X Figure 6.1.2.2: SEM micrographs showing interdendritic crack path along the elongated ferrite pools.
BWXT SERVICES, INC. 1140-025-02-24 126 BWXT SERVICES, INC. 1140-025-02-24 126 Figure 6.2.1.1: 4X macro photograph of metallurgical mount A2A7N.
Refer to Figure 5.11 for the sample orientation.
BWXT SERVICES, INC. 1140-025-02-24 127 BWXT SERVICES, INC. 1140-025-02-24 127 P -I I4 s I '_
q
. . E r
- 4 1 _
, . > ,- 4 at ,I.
It - ...
toR-I .
. d '--'I f. , 't I - .
.'.. ,.-- S ' ' ' : X .
. .1 - . - 1, . -:1 . I I
. ' . ' .' .' ' ' 'i I
I
. i ,".,I- , . .
.. I
- *I ,-
. I - , ,' i .I 4
. I -
I .', : . I
. . . . iw '.
, I . . - . . . I
- 8 ' ' * * * . . ' .
- - I . I
_ .^ :
if .
.- , . '. ... a : ..
.' .Z - . .
I : ':
' j ... .
f .
Et .d . .. .
- , ,, , , t Etched 48X Figure 6.2.1.2: Micrograph of a crack observed on A2A7N. The crack tip is estimated to be approximately 0.036" (0.91 mm) below the surface.
BWXT SERVICES, INC. 1140-025-02-24 128
_~~-
i ' ,.
W- K ' * ,~~~~~~~.Jf' X .'
i' ,-' ..'**
, ' .~~~~~~~~~~~ C
_ "- ' -; S - ,
t rM .'. ,-* ; _-^ if', .*
- P ' ji','.',.!{ o'.
/~~~~~35 Fiur 6...:Mcorpssoigitrrnlratc*IA n inerrauarcrckn o te xosd tanes see ladig
BWXT SERVICES, INC. 1140-025-02-24 129
.4 --
4,
--- S
>A 4-' * -
9
- - .1 x.
- f. > .
.*44 ... / 0,- -'-- .-
.0 S~
il -; .1Y f v . t.
375X Figure 6.2.1.4: Typical clad microstructure in the mid-thickness of the cladding.
BWXT SERVICES, INC. 1140-025-02-24 130 r L.4*
, ; *- ; v~~~, 4., *..-^..
~'- ; :^~r-
- -s V X* - ;.2 -; -
claddn. N Si.n.. . * - - , *I..G*- * -a - .present.
_;iu, 6.2.15 Tyicl',a mirstu r ner RSsdsufceof th';
375X~~~~~~~~~~~~5
/1~ ~~~ OOX Figure 6.2.1.5: Typical clad microstructure near RCS side surface of the cladding. No intergranular attack (IGA) was present.
BWXT SERVICES, INC. 1140-025-02-24 131
- ii +/-a65-rI ------
t -- '-X - -- IL Z Or
-,I,-, 11 T . II
'C'-
' I :'A ' .- -.;.
- 1 --
- -j! 11-I -.
7 z I -" , -, , . . 3. -I -1174 I ; " ,,A ,I I , , e; 1:)-i,7-"
I I ,I - .1-1 X ;'
1NA 14.'L I I NI i 5 la
,jCursor o025 kev 1O24 MntID = Li kMA iVert=i600 Whdow 0.005 -40.955= 323168 lnt EDS results for Area 1.
Figure 6.2.2.1: SEM micrograph showing the three deepest cracks in A2A7N. The maximum crack depth was approximately 0.056" (1.42 mm). EDS scans of areas 1, 2, and 3 and lines 1 and 2 (not included) indicated a generally uniform chemical composition (including Cr content) across the cladding thickness.
C.531
BWXT SERVICES, INC. 1140-025-02-24 132 BWTSRIEIC 14-2-22 3 ItI 1.,5-Ef? Lr. Crc-c Efrcr m-cf. A fF ocr z :: 21
-aa 0 ccc. vAt"+ O.XO7 QCL 1:044 1 1215 C4.744 Cr *' - 1.1-L 1,1.CFA : 0ID:'5 c0T-co I -1 CIE6 0 0C615 PaK 70Qii$ -.t%? 0.471 0 ~333 1.,19-1 Ni ,..i 6.u AIct O.X2' 0 17! 01E Fe
'I II 60e=r0.025 Icev 1116 L-- ID a U kal Ver=G,47 Wir&d.y 0.005 -40.95S5 311812C mnt EDS results for Area 2.
111 265-3_ ______ _______ _ ___
Er. 1r.v czml c".rr I-U A F ct C kJ occO VA.% OCel) .2OLcc, 2.?+/-) .1 9' 1H1l2 WK3 ..S197At%'O .0U. C.T.3 CQTr/ CYi2 L2MI Fe S ~~~~~~~~~~~~~~~~~~~
0 Kaor-0.OSS keV 613 at ID2,U kal ftvrt=6213 VWindow 0.005-40.955= 316922cnt EDS results for Area 3.
Figure 6.2.2.1 (cont.): EDS results for Areas 2 and 3.
BWXT SERVICES, INC. 1140-025-02-24 133 1/4j -<
b /
r\ 3 .'< Q+/-.St' 1' - .
A-t
' "t4.e -
>1K' ""
) -
p, *?
- 4, 1.i.
Si, ,.,..w
- 5 r.4&/; b) 1/4 tt '.-
Figure 6.2.2.2: Higher magnification SEM micrographs of crack tip, showing the interdendritic crack path along the elongated ferrite pools.
BWXT SERVICES, INC. 1140-025-02-24 134 BWXTSERVICES, INC. 1140-025-02-24 134~~~~~~~~~~~~~~~~~~~~~~~~~~
Sample A2A7S Knoop Microhardness 300.0 -
Y 250.0 -
M
<, 200.0-oCi) 0)
150.0 s~100.0-0.0 0.000 0.050 0.100 0.150 0.200 0.250 0.300 Distance from Upper Clad Surface, inches Figure 6.3.1.1: 4X macro photograph of metallurgical mount A2A7S. Refer to Figure 5.11 for the sample orientation. Knoop microhardness values exhibited lower hardness readings toward the exposed clad side (left side of graph), which was in contrast to A2A7M.
BWXT SERVICES, INC. 1140-025-02-24 135 4 p
.v.. . I
- .- . 4-
- f *1
- 45 A' 1
1 OUX 4
9.-
.4 fl,*
S.
.Z.f.
- . I.4
.1. t * - -
%(*
- /. ..
I
- m
- j * ' *-; S A I
- 4, .( hf t A .
,I .
6$ 4> (\t; ".t.. .
- 4. % is .. p I-.
-s -
4* / . -'S (
1'/
2 1-' .
.44 375X Figure 6.3.1.2: Micrographs showing intergranular attack (IGA) and intergranular or interdendritic cracking on the exposed stainless steel cladding.
BWXT SERVICES, INC. 1140-025-02-24 136 BWXT SERVICES, INC. 1140-025-02-24 136 S.,
I.
7 "' ,' .Y .
f As-polished 48X Figure 6.3.1.3: Micrographs of cracking observed on sample A2A7S.
Different cracks are shown.
BWXT SERVICES, INC. 1140-025-02-24 137 BWXT SERVICES, INC.
1140-025-02-24 137~~~~~~~~~~~_
P
- j N
- 1 IY
$ .1 bN 4'
0 I
--$1 h.
'V
-4
- 4-4.
-C 4 . A.
rKr-f%)
375X Figure 6.3.1.4: Typical clad microstructure in the mid-thickness of the cladding.
BWXT SERVICES, INC. 1140-025-02-24 138
- . .' , .. , : < \':: x ., - ;l. ,:. .. :
.n ,.-,, .......... _, . t- -_ .; ~~~~~~~~~t
,.,%-Z., ..........................
,'s
.. ,. .K D j.s;>. . ; w .,,.; * ; .; - . .
l v ~ ~ - t "I ~ r
. =N1 t _,, *t §.. r.-
~~~~~~~~~~~~tI-;,,._ -.. , ._i.t._
. -t r { , - .,- -,.-. . , . .-
i -_ i * *# '.'..A g~.- 's.;-3'7_ .-X' Figur6-.15 Tyia cla mcro;~strct*re nea RCS sid /,~, surac_ o f, the_
claddin*g.. a wa.s p.resent. e*I'A
- inte'rg,'.;u*ar.
.No
_ac
BWXT SERVICES, INC. 1140-025-02-24 139 11 1IZB6 -1
-i .Y.
Cr I q- 4 , 2. lU. 4'S' IC'CT I- "-t -,
1 I T "A Fe I
tIN.
-5 ft rI 10 Cuzscr=OX75 keV 1482 cnt ID = Li kal pVert=0190 Window 0.005 -40.955= 422988 cnt EDS results for Area 1.
Figure 6.3.2.1: SEM micrograph of the three deepest cracks in A2A7S. The maximum crack depth was approximately 0.056" (1.42 mm). These three crack tips are approximately the same distance from the underside surface. EDS scans of areas 1, 2, and 3 and lines 1 and 2 (not included) indicated a generally uniform chemical composition (including Cr content) across the cladding thickness.
BWXT SERVICES, INC. 1140-025-02-24 140 1112eG-3 Fe 8..
t8 f.Ps. Wu A 4 . C4~.. G: .E3L .3LrM Z.5R Ca 386 18 4S A..% C.9i 121 OL.1? I1M I24 Ph. V4 1.8 %O08P owl COU38 4.*.3 I.W 8 PC 84 X.Z77's.% C4.0 2. IX 091Z C.%As t.0311
~ i~I.%
IA Ct'~ 3141 L.03 I.W9 I.=:t A. ~ ~ ~~j~eJN1
.4x0r=.02S keV 1131 cnt ID U L kaM Veft=8194 %WirOW0.005 -40.955= 425515 cnt EDS results tor Area 3.
Figure 6.3.2.1 (cont.): EDS results for Areas 2 and 3. Note that the Cr peak was set at full screen height for Area 2.
BWXT SERVICES, INC. 1140-025-02-24 141 INC.SERVICE, BWXT 1140-25-02-24 14
-
- t.,....&..S.
4
- .'-,.sI t 4 C 5
,h *.-. i7 1/2' -
L--.-
Y4'C ' )-4g., -. I
.t% k.JKz\.Tf -
pt.1 9., **' I v *. (4 v.,-'
2 I
U ... ae Si ii..
BSE 300X Figure 6.3.2.2: Higher magnification SEM micrographs of crack tip, showing the interdendritic crack path along the elongated ferrite pools.
BWXT SERVICES, INC. 1140-025-02-24 142 BWXT SERVICES, INC. 1140-025-02-24 142 I- F: '.'
h
> A4,...
?, ri
- ' R .' -
- n
'2 I *. m-em cc.
SE 50OX Figure 6.3.2.3: Secondary electron SEM images of crack tip, showing the interdendritic crack path along the elongated ferrite pools.
BWXT SERVICES, INC. 1140-025-02-24 143 BWTRIEIC 14-2-22 4 Figure 6.4.1.1: Low magnification SEM mosaic showing the opened main crack (sample A2A7-LIA). Refer to Figures 5.11 and 5.12 for the sample location. The exposed cladding surface is oriented downward in the SEM micrographs.
BWXT SERVICES, INC. 1140-025-02-24 144 BWXT SERVICES, INC. 1140-025-02-24 144 Figure 6.4.1.2: Near mosaic area "A". Heavy deposits are present toward the exposed side of the cladding (darker contrast in BSE micrograph).
Fracture morphology is interdendritic in nature.
BWXT SERVICES, INC. 1140-025-02-24 145 BWXT SERVICES, INC. 1140-025-02-24 145 Figure 6.4.1.3: Near mosaic area "B". Cracking is intergranular/interdendritic.
BWXT SERVICES, INC. 1140-025-02-24 146 BWXT SERVICES, INC. 1140-025-02-24 146 Figure 6.4.1.4: Near mosaic area "C". Fracture mode is intergranular or interdendritic for in-service cracking and ductile tearing for lab opened-up fracture.
BWXT SERVICES, INC. 1140-025-02-24 147 BWXT SERVICES, INC. 1140-025-02-24 147 Figure 6.4.1.5: Near mosaic area "D". Fracture mode is intergranular or interdendritic for in-service cracking and ductile tearing for lab opened-up fracture (upper right).
BWXT SERVICES, INC. 1140-025-02-24 148 101,177M,,Ir Figure 6.4.1.6: Near mosaic area "E". Cracking is intergranularlinterdendritic.
BWXT SERVICES, INC. 1140-025-02-24 149 BWXT SERVICES, INC. 1140-025-02-24 149 I
a1232-t
.0 5S mer'ye.Davis Besse Feed A2 -A7-I. i -A ED~S 3f rnea 1,imaqe 111t232.
U~xoatd, 10 kV.
Elemer'ts: r. 0,. Al.. St, Cr.- r~e Pnss~be Trace: Cl. 3Ji Cr ~
C C! Cr Id
,.14 z 5 r tame i nla ma I { I Fe Ni di~
I~~~~~~~~~~~~~~~ 10 go9r=0.035 keY 403 ant ID = Li kl ert=Ul692 Wndow 0.005 40.55= 373L68 n ____
EDS results for area I above.
Figure 6.4.1.7: SEM micrograph and EDS results for deposited region near area "E".
The corrosion deposits contained carbon, oxygen, along with iron, aluminum, silicon, and chromium. Possible trace levels of nickel and chlorine were also detected in this area.
c57
BWXT SERVICES, INC. 1140-025-02-24 150 BWXTINCSERVCES, 1140-02502-24 15 iiit I1-1
.0 Sptcmien: Davis Besse Heaa AZ-A7LL -
EDS3f poar I . image 1U23t.
Uricoated, 10 kV.
Elernert: C, 0, Si. tr, F'e,Ni P~ssble Trace: Al, 5job Ca OD Fe C,
C Ni i
I~
ki SC
,I Ma QO I Fe Ni xi 10 i 5
'1Cursor=0.035keV 48 Cnt ID - Luka rt-41 WkIow O.OOS - 40.95=__"401 to_
EDS results for point 1 above.
Figure 6.4.1.8: Higher magnification SE micrograph and EDS results for a grain boundary deposit near area "E". This area contained primarily carbon, oxygen, silicon, chromium, iron, and nickel. Lesser amounts of aluminum, sulfur, and calcium were also detected.
BWXT SERVICES, INC. 1140-025-02-24 151 Sample A2A5C Knoop Microhardness (Exposed Clad) 350.0 _
< 300.0 _ 9 ci 250.0- -
c) 200.0- -
,: 150.0-gro100.0O s: 50 0 0.0( 0 0.050 0.100 0.150 0.200 0.250 Distance from upper (exposed) clad surface, inches Sample A2A5C Knoop Microhardness (Low Alloy Steel and Stainless Clad)
<350.0 -
250.0 -
I,150.0 -
O 00 Low Alloy Steel Stainless Clad s 0.0 0.000 0.100 0.200 0.300 0.400 Distance from upper surface of mount, inches Figure 6.5.1.1: 4X macro photograph of metallographic mount A2A5C, along with Knoop microhardness data. Refer to Figure 5.13 for the sample orientation. The two Knoop microhardness traverse lines are visible in the macro photo. The significant microhardness variations occur in the heat affected zone of the low alloy steel and the cladding adjacent to the fusion line.
BWXT SERVICES, INC. 1140-025-02-24 152 Figure 6.5.1.2: Low magnification photograph of mounted sample A2A5C after chemical etching to reveal the cladding microstructure. It did not appear that a weld deposition change occurred in this region.
BWXT SERVICES, INC. 1140-025-02-24 153
-L en ., *~~~~~~~~~~~~~~~~~~~~~~-',
... . .~~~~~~~~ .4 Etched 48X Figure 6.5.1.3: Micrograph showing the undercutting due to boric acid corrosion in the RV head low alloy steel at the interface between low alloy steel (above the notch) and stainless steel cladding (below the notch).
1,>' " , . - r -
~~~~~
. 7 ',. I, OL.,L r --' t ;_*t-~ t t '
- 1 a: . *'E *' . .
- ~~~~ - .' ',1 *b- ,g ; ' '
S E- ' -*' pg
-X, Etched 375X ' , 1:
Figure 6.5.IA: Micrograph showing the interface between low alloy steel (above) and stainless steel cladding (below). The austenitic grains in the first interface layer on the stainless steel cladding side are equiaxed and growing preferentially from the ferrite grains (low alloy steel). The subsequent grain growth in the cladding is columnar.
BWXT SERVICES, INC. 1140-025-02-24 154 BWXT SERVICES, INC. 1140-025-02-24 154 L .. .
', -: O u: ~~~~~~
' ;0'.: , , , , : . , . '. .
-'S Etched 1OOX
\..
, ". * *,*<Ei>7,i .
E tc he d 37 5X Figure 6.5.1.5: Micrographs of the cladding surface exposed due to boric acid corrosion of the RV head low alloy steel. Intergranular attack (IGA) of stainless steel cladding to a depth of the first or second layers of grains is clearly visible. The IGA is probably due to oxygenated and highly concentrated boric acid. There was no evidence of plastic deformation observed in the cladding in this area.
BWXT SERVICES, INC. 1140-025-02-24 155 BWXT SERVICES, INC. 1140-025-02-24 155 375X Figure 6.5.1.6: Micrographs showing typical stainless steel cladding microstructure.
The dendritic solidification structure is delineated by small pools (or islands) of ferrite in an austenitic matrix.
BWXT SERVICES, INC. 1140-025-02-24 156 BWXT SERVICES, INC. 1140-025-02-24 156 Sample A2A2B3 Knoop Microhardness 350.0 -
300.0 - at
,,250.0-,^ . * < \
= 200.0-co 150.0-100.0 E 50.0-0.0 -
0.000 0.100 0.200 0.300 0.400 0.500 Distance from bore ID surface, inches Figure 7.1.1.1: Macro photograph and Knoop microhardness results for metallographic sample A2A2B3 (see Figure 5.2 for the sample orientation). The lower concave surface is the I.D. of the nozzle 3 bore from the nozzle removal process. The crack tips of the two cracks are estimated to be approximately 0.24" and 0.20" below the surface, respectively. The indentations from the microhardness traverse are visible. The elevated microhardness level near the surface is due to the surface cold work layer from the boring of nozzle 3 removal process (see Figures 5.2 and 7.1.1.5).
BWXT SERVICES, INC. 1140-025-02-24 157 BWXT SERVICES, INC. 1140-025-02-24 157 e-e
- I~ ~~ ~ ~ ~ ~ ~~~~~A Figure 7.1.1.2: Micrographs showing the crack at -180o in sample A2A2B3.
Top as-polished, bottom etched. Both micrographs 24X.
- t2,.1
- ..... '¶ J'Jza~t'.v * - . -
~:*%~<rs 4.A~.v.>":.t~r. - . ' d -t Figure 7.1.1.3: Typical microstructure of sample A2A2B3. The grain size and dendritic structure within each grain are consistent with typical Alloy 182 weld.
BWXT SERVICES, INC. 1140-025-02-24 158
-.-* .. .* **iY T" J. " A
- 1 I
r
'C.,
I
- 1j,' C
- p. .. I (
- 9 I OOX
. .4 375X Figure 7.1.1.4: Higher magnification micrographs of the crack tips. Cracking is intergranular or interdendritic.
BWXT SERVICES, INC. 1140-025-02-24 159 4 4 S ..
cla .-
I.
- . 4: I r,.,
1.1. .
IP
-I . .;
t . ..
f . . . 4
-C. C
.I . ..
375X , ..
Figure 7.1.1.5: Higher magnification micrographs of the cracking at -180° near the bored surface. The bored surface shows evidence of surface cold work. The surface cold work is due to the nozzle removal from the RV head and is not related to the J-groove weld fabrication process.
BWXT SERVICES, INC. 1140-025-02-24 160 BWXT INC.1140-025-02-24 SERVICES, 160~~~~~~~~~~~~~
I -1,--.
!I',.
I. I, il. Nozzle 3 II Bore I.D.
i I.1 I6 .
I .
I I 4X Figure 7.2.1.1: Macro photograph of metallographic mount sample A2A6B2 (see Figures 5.4 and 5.5 for the sample orientation). The axial cracking at -10° is through the J-groove weld, in contrast to the cracking near 1800, which was partially through the weld. A slightly higher magnification micrograph is also provided.
BWXT SERVICES, INC. 1140-025-02-24 161 BWXT SERVICES, INC. 1140-025-02-24 161 Figure 7.2.1.2: Higher magnification micrographs of the J-groove weld cracking.
Cracking is intergranular or interdendritic, similar to the cracking at -180° in Figure 7.1.1.4.
BWXT SERVICES, INC. 1140-025-02-24 162 BWXTSERVICES, 1140-025-02-24 INC. 162~~~
Figure 7.2.1.3: Typical microstructure of sample A2A6B2, which was similar to Figure 7.1.1.3 (at -180°).
BWXT SERVICES, INC. 1 140-025-02-24 163 BWXT SERVICES, INC. 1140-025-02-24 163 Figure 7.2.2.1: BSE micrograph showing portion of crack filled with corrosion products. The EDS results indicated high concentrations of carbon, oxygen, iron, and nickel.
BWXT SERVICES, INC. 1140-025-02-24 164
- A
- .'- -*. NT
. a -. 1 S ii am sa.,
BSE 500X 111381-l Spe!xntn: DWrS BeSSe EDS olsnalI area 1, frna~c1I1381.
Caton Cotd 20 kYV.
.0 re, Elermer: C,0, Al, Si, Ti, Cr, MhV. f.I, ft, Sn Ptnisle Trace Ca, overlapp2ed In Sn.
NI ib i I
I (H
14.b I N11 I,1r
'(NIA "
(b8i l CAFE
^4^~~~~~~~~~~~~~~~ l < ,Tl J~~~~~~~~~~~~ -
M A I
-*-I ............................ I......... ** .... a S 10 arsor -i3.025 keV 1267 ent ID = U kaM IVlrt=-4000 Whorr 0.005 *40.955= 431661 cnt EDS results for area 1 above.
Figure 7.2.2.2: BSE micrograph showing corrosion products near crack tip. The EDS results collected from the area 1 indicated high concentrations of carbon, oxygen, niobium, titanium, chromium, manganese, iron, and nickel.
BWXT SERVICES, INC. 1140-025-02-24 165 BWXT SERVICES, INC. 1140-025-02-24 165 Figure 7.2.3.1: Macro photograph of metallographic mount A2A6A2E1 (see Figure 5.6 and 5.10 for the sample orientation). Cracking was partially through the J-groove weld in the sample plane.
BWXT SERVICES, INC. 1140-025-02-24 166
.. T*T:*2;T-: - -.
1*J
- n-pit..:,
-.. C.-". I-J
- 0. q)*
- 4 6-
-~ *- . ~
- IF7
.Etched 13X.,-..
Figure 7.2.3.2: Micrograph showing axial cracks in the lower portion of the J-groove weld at -10°. The crack maximum depth is approximately 0.45" beneath the bore I.D.
surface.
BWXT SERVICES, INC. 1140-025-02-24 167 BWXTSERVICES,INC.
1140-025-02-24 167~~~~~~~~~~~~~~
Figure 7.2.3.3: Cracks located near the bored surface. Surface cold work layer is due to the boring (nozzle removal) process.
BWXT SERVICES, INC. 1140-025-02-24 168 1140-025-02-24 168 BWXT SERVICES, INC.
7_
7M~
rJ Etched I OOX Etched 375X Figure 7.2.3.4: Interdendritic or intergranular cracking in the J -groove weld away from the bore I.D. surface.
BWXT SERVICES, INC. 1140-025-02-24 169 Figure 7.2.3.5: Crack tips toward the J-groove weld O.D.
BWXT SERVICES, INC. 1140-025-02-24 170
_ ~ ~ ~ * . . . . .-
!~~ . .t*Bi
- ., . . . ; z *P i -,I -
_ -;'.. 'a.'A 7' lo,, ' -.N. , . .."
- ** ; I *E a',*
' '7HS * '-. * . ' j* *:
Etched..375X . -...- P..
Figure 7.2.3.6: Crack detail from Figure 7.2.3.5.
BWXT SERVICES, INC. 1140-025-02-24 171 BWXT SERVICES, INC. 1140-025-02-24 171 B_ _X1 X ~~~~~~~~~Nozzle
_^16 -- 9 _ g ~~~~~~#3 bore
^ _ t Lo~~~~~wer
_t111 ~~~~~~~surfce In_ -of J-weld 4X Figure 7.2.4.1: Macro photograph of sample A2A6B3 with the middle portion of the axial cracking at -10° opened-up for SEM. Refer to Figures 5.4 and 5.5 for the sample location.
C(po