Welding Update

(Overview, Code Cases, and Alloy 52)

Industry/U.S. NRC Materials Program Meeting
Rockville, MD
Thursday June 5, 2013

Steve McCracken
EPRI Welding & Repair Technology Center
 New Report on ASME Section XI Welding Issues
EPRI Report1025169
• Welding & Repair Technical Issues
in ASME Section XI
– Will be a single reference for WRTC
members to review status and new
code changes and initiatives
– Intent is to provide a “living”
document that is updated on a
yearly basis
– Will include significant Section XI
issues and revisions
– Will provide status of on-going
activities
Key Contributors to first issue:
Dick Smith, Nick Mohr,
Dave Waskey, Darren Barborak,
Steve McCracken

© 2013 Electric Power Research Institute, Inc. All rights reserved. 2

 Report 1025169 Table of Contents

 Validity of Hardness as a Measure for Temperbead HAZ

Toughness
 Simulated PWHT for Temperbead Qualifications
 Alternate Impact Test Rules for Temperbead Qualifications
 Elimination of Hydrogen Bakeout for SMAW Temperbead
 Methods to Validate Chromium Recovery
 Interpass Temperature Controls for Temperbead and Weld
Overlays
 Excavate and Weld Repair Code Case
 Status of Code Cases
- N-638-7, N-666-1, N-740-2, N-786, N-789, N-818
 Appendices Include August 2012 ASME WGW – NRC Staff
Meeting Presentations

© 2013 Electric Power Research Institute, Inc. All rights reserved. 3

 Code Case N-818 Fitness for Service
Steve McCracken, Joshihisa Sekinuma, Steve Swilley,
Sam Ranganeth, Owen Hedden, Dave Cowfer, Eric Willis

References:
1. S.L. McCracken, S.M. Swilley, Y. Sekinuma, O. Hedden, D. Cowfer, S. Ranganath, “Proposed ASME Section III
Code Case – Reduction of NDE Weld Repairs,” ASME PVP 2011 Conference, Baltimore, MD, USA, PVP2011-
57675
2. Technical Advanced Nuclear Technology: Reduction of American Society of Mechanical Engineers III Weld
Fabrication Repairs—Fitness for Purpose. EPRI, Palo Alto, CA: 2010. 1021181.

© 2013 Electric Power Research Institute, Inc. All rights reserved. 4

 Section III Code Case N-818
(Fitness for Service)

N-818 was approved December 2011 and will

be in Supplement 8 of 2010 Edition of ASME

© 2013 Electric Power Research Institute, Inc. All rights reserved. 5

 Section III and N-818 Process Tree

ASME
Section III
Workmanship

N-818
Code Case
FFS

© 2013 Electric Power Research Institute, Inc. All rights reserved. 6

 Code Case N-818 Background

• Code Case N-818 is intended for ASME Section III new

construction
- Applies when Section III radiography detects rejectable flaws
- Uses simple acceptance criteria based upon ASME Section
XI (2009 and later) PSI acceptance criteria
- Minimizes or eliminates new construction weld repairs that
have caused many instances of Stress Corrosion Cracking
- EPRI did extensive UT work to demonstrate ability to
detect and size construction-type flaws in full weld
volumes
- EPRI is currently working to resolve Regulator concerns with
using UT in lieu of RT

© 2013 Electric Power Research Institute, Inc. All rights reserved. 7

 Will cover in “Mitigation – Excavate and Weld Repair”
Presentation – Day 2, Thursday June 6th

Excavate and Weld Repair (EWR)

Steve McCracken, Eric Willis, Jon Tatman, Pete
Ricardella, Dick Smith, Brad Thigpen, Jack Spanner

Reference:
Topical Report: Application of the Excavate and Weld Repair Process for Repair and Mitigation of Alloy 182 and 82 in
PWRs. EPRI, Palo Alto, CA: 2010. 1021012.
Presentation

© 2013 Electric Power Research Institute, Inc. All rights reserved. 8

 Temper Bead Hardness Requirements
Steve McCracken, Dick Smith, Darren Barborak

References:
1. S.L. McCracken, R.E. Smith and D. Barborak, “Validity of Hardness Criteria to Demonstrate Acceptable Temper
Bead HAZ Impact Properties for Nuclear Power Applications,” ASME PVP Conference, Paris, France, July
2013, PVP2013-97793 (accepted for the conference proceedings)
2. P. Lester, M. Keller, J. Frank, D. Barborak, R.E. Smith, S.L. McCracken, “Temperbead Welding and International
Codes,” EPRI Welding and Repair Technology for Power Plants, International EPRI Conference, Marco Island,
FL, June 2012
3. Welding and Repair Technology Center: Welding & Repair Technical Issues in ASME Section XI. EPRI, Palo
Alto, CA: 2012. 1025169.
4. Presentation, “Validity of Hardness to Demonstrate Acceptable Temper Bead HAZ Impact Properties in Nuclear
Applications (Reference PVP2013-97793)”, ASME Section IX Meeting; Miami, Florida; May14, 2013

© 2013 Electric Power Research Institute, Inc. All rights reserved. 9

 Hardness Criterion for Temper Bead Qualification – EN/ISO

• EN/ISO codes, standards and specifications do not directly

address temper bead welding similar to ASME
• Hardness testing is often applied and used as criterion for
temper bead qualification in addition to impact testing
(reference EN ISO 15614-1)
– Typical acceptance criterion applied 380 HV10 maximum
– Single hardness readings must not exceed maximum
– Hardness measurement required 2mm below surface and 2mm
above root of qualification groove weld
• ASME Section IX QW-290.3 specifies hardness as an essential
variable for temper bead procedure qualification where book section
does not specify impact testing

© 2013 Electric Power Research Institute, Inc. All rights reserved. 10

 Is Hardness Testing Appropriate for Temper Bead?

• Issues with use of maximum harness criterion for temper bead

weld procedure qualification
– Hardness alone, without knowing the microstructure, is not
adequate for verifying acceptable HAZ tempering by a temper
bead welding procedure (i.e., HAZ with acceptable fracture
toughness)
Impact testing historically used to verify acceptable fracture toughness

– Rejection by a single hardness reading (as often required in

EN/ISO codes) is not reasonable
– Use of maximum hardness criterion can potentially lead to
acceptance of HAZ properties with improperly tempered HAZ
microstructures with poor toughness

© 2013 Electric Power Research Institute, Inc. All rights reserved. 11

 Tempered Martensite Has Superior Impact Properties

From Lundin & Mohammed [7]

• Top curve - tempered
martensite has superior
impact energy from high to
low temperatures
• Middle curve - mixed
microstructures of
tempered martensite plus
tempered bainite shows
sharp temperature
transition
• Bottom curve - tempered
martensite plus tempered
pearlite has poorest impact
energy

© 2013 Electric Power Research Institute, Inc. All rights reserved. 12

 EPRI Temperbead Testing on P-3 Gr-3 Materials

• SA-508 and SA-533 manufactured by

modern fine grain melting practice
• High hardenability & excellent toughness
• No simulated PWHT

• Charpy specimens taken

at 1/4T location
• Ambient temperature • HAZ and UBM charpy
consistent layer machine specimens are alternated
GTAW temperbead along temperbead weld
• ER80S-B3L filler metal
• Buildup with FCAW
after 4 GTAW layers
© 2013 Electric Power Research Institute, Inc. All rights reserved. 13
 Charpy Transition Temperature Curves
P-3 Gr-3 SA-508 Class 2 Forging (JSW Ht. 02D591-1-1)
~190ft-lb at
TNDT+60°F

Absorbed energy (ft-lb) versus temperature (°F)

© 2013 Electric Power Research Institute, Inc. All rights reserved. 14
 Hardness Map and Compiled Micro Image
P-3 Gr-3 SA-508 Class 2 Forging (JSW Ht. 02D591-1-1)

© 2013 Electric Power Research Institute, Inc. All rights reserved. 15

 Histogram of HAZ and First Temperbead Layer
P-3 Gr-3 SA-508 Class 2 Forging (JSW Ht. 02D591-1-1)

• Only values
>240HV plotted
• Values
correspond to the
HAZ and weld
metal
1.1% • Values <240HV
considered to be
base metal
• Only 15 data
points out of 1371
(1%) were above
380HV

© 2013 Electric Power Research Institute, Inc. All rights reserved. 16

 Maximum Hardness Limit is Not Appropriate

• Superior toughness properties in temperbead HAZ

– 165 ft-lb & 80 MLE at drop weight TNDT for the SA-533 plate
– 190 ft-lb & 80 MLE at drop weight TNDT for the SA-508 forging
• Hardness maps reveal only ~1% of counts e 380HV (0.2 kg)
• Low hydrogen processes, controls, and low hydrogen
consumables are adequate to provide acceptable margin
against HIC in HAZ with e 380HV
• Small random areas of peak micro-hardness do not influence
temperbead HAZ toughness
• Hardness may be used only if HAZ microstructure is properly
characterized
• EPRI is investigating alternative approaches for using
hardness for acceptance of temperbead welding procedures

© 2013 Electric Power Research Institute, Inc. All rights reserved. 17

 Impact Testing for Temper Bead Qualification
Steve McCracken & Dick Smith

References:
1. S.L. McCracken and R.E. Smith, “Alternative Approach for Qualification of Temperbead Welding in the
Nuclear Industry,” ASME PVP Conference, Toronto, Canada, July 2012, PVP2012-78571
2. Welding and Repair Technology Center: Alternative Rules for Temperbead Qualification. EPRI,Palo
Alto, CA: 2012.1025168.
3. Welding and Repair Technology Center: Welding & Repair Technical Issues in ASME Section XI. EPRI,
Palo Alto, CA: 2012. 1025169.

© 2013 Electric Power Research Institute, Inc. All rights reserved. 18

 Temperbead Qualification Issues
• Qualifying temper bead weld procedures on modern low alloy steel
(LAS) base materials (e.g., SA-508 forging & SA-533 plate) can be
problematic:
– New LAS steels exhibit significantly higher impact energy and
much lower transition temperature compared to vintage steels
– Temperature relationship between the Drop Weight (DW) test and
Charpy test is altered and prescribed test temperatures often
produce misleading HAZ results
• TNDT + 60°F (as set by the drop weight test) is typically on the upper
shelf (100% shear) for Charpy testing and data scatter is significant
• Mils Lateral Expansion (MLE) is limited by Charpy specimen
geometry and general material properties
• Temperbead procedure requirements may not be met simply
because the prescribed Charpy test temperature is too high

© 2013 Electric Power Research Institute, Inc. All rights reserved. 19

 Proposed Alternative to Code Case N-638-6

• Alternative provision will:

– Eliminate drop weight test
– Charpy V-notch test
temperature may by
determined as follows:
• Review of test plate CMTR
• Develop a full transition
curve for test plate by
Charpy V-notch testing
• Select test temperature
where Charpy V-notch
TNDT + 60°F
results in the test plate
exhibit 35 to 50 mils lateral
expansion
• Test temperature for Charpy
tests should be in transition Charpy test BM &
temperature mid-range HAZ in this
hashed region

© 2013 Electric Power Research Institute, Inc. All rights reserved. 20

 Alternative Charpy V-notch Requirements

New Charpy impact test

provisions are easily added as
alternative in Code Case N-638

© 2013 Electric Power Research Institute, Inc. All rights reserved. 21

 ASME Code Cases – Status & Issues

© 2013 Electric Power Research Institute, Inc. All rights reserved. 22

 SMAW Temperbead Welding

• Eliminate 48 Hour Hold for IWA-4600 SMAW Temperbead

Applications (Record # 06-859)
– Will permit final weld NDE as soon as welding and final surface
prep is complete
– WRTC provided white paper (EPRI Doc No. 1021076) with
technical basis for elimination of the 48 hr hold for SMAW

• Similar and Dissimilar Metal Welding Using Ambient

Temperature SMAW Temperbead Technique (RRA 06-09
Record No. 06-859)
– New code case for SMAW ambient temperature temperbead
– Eliminates 48 Hour Hold (EPRI Doc No. 1021076)
– Same format as N-638

© 2013 Electric Power Research Institute, Inc. All rights reserved. 23

 Ambient Temperature Temperbead (N-638-6)

• N-638-6 Ambient temperature temperbead rules

(Board Approved; Supplement 6 to 2010 Edition; Record # 10-650)
– Revision needed to incorporate Section IX QW-290 temperbead
qualification rules
– NRC Longstanding Temperbead Open Items
 Hardness criterion (euro codes specify hardness for temperbead)
 Interpass measurement method/technique

• N-638-7 Ambient temperature temperbead rules

(Approved Standards Comm. XI May 2013; Record # 10-550)
6 Incorporates alternative Charpy testing requirements
6 Permits qualification without simulated PWHT on test plate

© 2013 Electric Power Research Institute, Inc. All rights reserved. 24

 Weld Overlay for Repair & Mitigation

• N-754 for Optimized Weld Overlay (OWOL) for PWSCC

Mitigation & Repair (Approved Stds Committee XI June 2011; Board
Approved; Supplement 6 to 2010 Edition; Record # 06-500)
– OWOL thinner and efficient option for large bore RCS dissimilar metal weld
– ISI prior to OWOL installation per N-770-2
– Area increased from 500 in2 to 1000 in2

• N-740-3 Structural Weld Overlay (SWOL) Record # 09-822; Need

to address Standards Committee May 2012 letter ballot negatives
– Revise for consistency with N-754 (OWOL)
– Response / resolution to NRC negatives
– Take out PSI & ISI and reference N-770-2
– Perform ISI prior to SWOL installation per N-770-2
– Include recent changes in MRP-169
– Increase area from 500 in2 to 1000 in2

© 2013 Electric Power Research Institute, Inc. All rights reserved. 25

 Inlay / Onlay for Repair & Mitigation

• N-766 Nickel Alloy Inlay /Onlay for PWSCC Mitigation and

Repair (Record # 07-1682; Passed Std Committee XI Dec 2010; Board
Approved; Supplement 4 to 2010 Edition)
– Rules for pipe ID inlay (~1/8” ID excavation) or onlay (no
excavation) with 52M
– Alternative to SWOL and OWOL

• N-803 Ambient Temperature Underwater Laser Beam

Welding for PWSCC Mitigation and Repair (Record # 09-1690;
Passed Stds Committee XI Feb 2011; Board Approved; Supplement 5 to
2010 Edition)
– Rules for laser beam welding of 52M inlay/onlay without need to
drain reactor vessel
– WEC / PCI development and demonstration work at WRTC
facilities is complete (moved laser to Lake Bluff)

© 2013 Electric Power Research Institute, Inc. All rights reserved. 26

 N-786 Sleeve Repair for Leak Mitigation
• N-786 Sleeve Reinforcement of Class 2 & 3 Moderate
Energy CS Piping
(Adopted; Supplement 5 to 2010 Edition; Record # 09-1691)
– Permits 360˚ split sleeve repair of degraded piping (wall thinning
with or without leakage)
– Permits reinforcement Type A (open ends) split sleeve or full
structural Type B (sealed ends) split sleeve

© 2013 Electric Power Research Institute, Inc. All rights reserved. 27

 N-789 Pad Repair for Leak Mitigation
• N-789 Pad Reinforcement for Raw Water Piping
(Adopted; Supplement 6 to 2010 Edition; Record # 10-1106)
– Permits 360˚ (sleeve) or partial (pad) repair of degraded raw water
service piping (wall thinning with or without leakage)
– Permits structural pad or pressure pad repair of degraded and/or
leaking raw water piping

© 2013 Electric Power Research Institute, Inc. All rights reserved. 28

 Alloy 52M Hot Cracking
Steve McCracken & Jon Tatman

References:
1. Welding and Repair Technology Center: Measures to Minimize 52M Hot Cracking on Stainless Steel Base Materials. EPRI, Palo
Alto, CA: 2012. 1025167.
2. S.L. McCracken and J.K. Tatman, Influence of Austenitic Stainless Steel Base Metals on Hot Cracking Susceptibility of High
Chromium Nickel-Base Filler Metals, Proc. ASME PVP Conf., July 15-19, 2012, Toronto, ON, Canada Paper No. PVP2012-
78614
3. Materials Reliability Program: Preliminary Report – Alloy 52M Hot Cracking Study and Prevention Guide (MRP-310). EPRI, Palo
Alto, CA: 2011. 1022885.
4. S.L. McCracken and R.E. Smith, Evaluation of Filler Metal 52M (ERNiCrFe-7A) Hot Cracking When Welding on Cast Austenitic
Stainless Steel Base Materials, Proc. ASME PVP Conf., July 17-21, 2011, Baltimore, MD, Paper No. PVP2011-57703
5. S.L. McCracken and R.E. Smith, Behavior and Hot Cracking Susceptibility of Filler Metal 52M (ERNiCrFe-7A) Overlays on Cast
Austenitic Stainless Steel Base Materials, Hot Cracking Phenomena in Welds III, Springer-Verlag, pp. 333-352 (2011)
6. S.L. McCracken, B.T. Alexandrov, J.C. Lippold, J.W. Sowards, and A.T. Hope, Hot Cracking Study of High Chromium Nickel-
Base Weld Filler Metal 52MSS (ERNiCrFe-13) for Nuclear Applications, Proc. ASME PVP Conf., July 18-22, 2010, Bellevue,
WA, Paper No. PVP2010-25787.

© 2013 Electric Power Research Institute, Inc. All rights reserved. 29

 EPRI Technical Report 1025167 – December 2012

• Welding and Repair Technology Center: Measures to Minimize

52M Hot Cracking on Stainless Steel Base Materials
• Issue Date: December 2012
• Overview
– Background on hot
cracking experience
– Focus on 52M
– Hot cracking test approach
– Test results
– Discussion with measures
to minimize hot cracking
– Dilution control & buffer
layer options
– Future work

© 2013 Electric Power Research Institute, Inc. All rights reserved. 30

 Issue - 52M and 152 Hot Cracking

Example of 52M hot cracking on

CF8A pipe clad with ER308L
Base metal is SA-351 CF8A
0.019% S, 0.032% P, 0.72% Si

• Hot cracks in 52M weld bead on

CF8A CASS base material
• 52M layer (right) shows multiple
liquid penetrant crack indications

© 2013 Electric Power Research Institute, Inc. All rights reserved. 31

 Bead-on-Plate Testing Approach

Bead-on-Plate Setup CASS Specimen

152-152M Beads on CASS Specimens

Machine GTAW Setup

52M Beads on CASS Specimens
© 2013 Electric Power Research Institute, Inc. All rights reserved. 32
 Range of Materials and Weld Parameters
GTAW
No. Filler AWS
Alloy Wire (phase
Spec. 1)
Heat No. Cr Fe Si Mn C P S
a 52M ERNiCrFe-7A NX76W5TK 30.12 8.68 0.11 0.77 0.02 0.003 0.00005 0

Material Sample b ERNiCrFe-7A

52M Element NX74W8TW 29.75 8.75 0.11 0.74 0.02 0.01 0.001 0

Type ID C Si Mn P S d 52M
Cr ERNiCrFe-7A
Mo Ni NX7588TK
Al Co29.95 8.81
Nb 0.12Ti 0.023 0.004 0.0006
0.75 Fe 0

CASS CF8A 57 2nd0.0227

CF8A0.0817
CASS sample
0.756 0.0246set with desired
0.0031 19.92 S range
0.400 8.88
c 52MSS ERNiCrFe-13 NX77W3UK
0.0014
29.49
0.0302
8.79
< 0.0040
0.11
0.0040
0.31 0.023 0.004 0.00005
69.8
2
e 52i ERNiCrFe-15 187775 26.98 2.55 0.05 3.04 0.04 0.002 0.001 2
(CASS-a Set) 58 0.0695 0.0752 0.797 0.0319 0.0046f 19.93 0.401ERNiCr-3
8.61 < EXD63590
0.0010 Element
0.0277
Material Sample 82 21.35 < 0.0040
0.53 0.00452.9 70.0
0.16 0.033 0.003 0.001 2
59 Type
0.0431 0.0695 ID0.754 C
0.0288 Si
0.0023 Mn
19.98 P
0.404 S
8.45 Cr
< 0.0010 Mo
0.028 Ni
< 0.0040 Al
0.0036 Co
70.2 Nb Ti
60 0.0405
CASS CF8A 0.945A11N 0.744 0.0261
0.0398 0.0019GTAW
0.0826 0.751 Filler
0.402 Wire
20.02 0.0121 8.45 (phase
0.00051 20.55 2)
0.0016 0.0273
0.415 <8.56
0.0040 0.0012
0.0044 0.0255
69.3 < 0.0040 0.004
No. Alloy AWS Spec. Heat No. Cr Fe Si Mn C P S
61 (CASS-b
0.0483
Set) 0.953 A120.734 0.0268 0.0737
0.0444 0.0019 0.771
20.06 0.0101
0.400 0.0111
8.39 0.0017
20.00 0.0278
0.424 <8.63
0.0040 0.0045
0.0041 0.0237
69.3 <0.01
0.0040 0.0050
B 52M ERNiCrFe-7A NX74W8TW 29.75 8.75 0.11 0.74 0.02 0.001
62 0.0581 0.959 A130.720 0.0278 0.0027 20.14 0.399
0.0471 0.0764 E 0.771 52i 0.0112 8.34
0.0264
ERNiCrFe-15
0.0026
20.22 0.0271
187775 0.424
< 0.0040 0.05
0.00413.040.0232
26.98 8.522.55 0.0023
69.3
0.04 < 0.0040
0.002 0.0042
0.001
63 0.0446 1.95 A21N
0.741 0.0230 0.989
0.0385 0.0017F 0.746
19.83 0.403ERNiCr-3
82 0.011 8.46
0.000890.0023
20.23 0.0275
EXD63590 21.35<8.45
0.418 0.0040 0.00472.9 0.025
0.16
0.53 0.0088 68.5
0.033 0.003
< 0.001
0.0040 0.0062
64 0.0581 1.98 A220.734 0.0404
0.0225 0.0018
0.939 M 19.84
52MSS 0.410
0.768 0.0114 8.45
ERNiCrFe-13
0.0121 0.0025
HV1500 0.0268
19.82 29.49< 0.0040
0.422 0.0044
0.034 0.001
8.53 0.0010 0.211 68.4
0.033
0.0236 0.002
< 0.001
0.0040 0.005
65 0.0470 1.95 A230.756 0.0450
0.0243 N
0.0025 0.757 52
19.83 0.0126ERNiCrFe-7
0.409 0.0326
8.53 NX6966JS
0.0029 29.14 8.97 0.18 0.72 0.007 0.003 0.003 0
0.918 19.98 0.0276
0.427 <8.460.0040< 0.0010
0.0046 0.0234
68.4 < 0.0040 0.004
O 622 ERNiCrMo-10 XX2464BK 20.64 2.30 0.03 0.23 0.005 0.01 0.0001
66 0.0531 0.0915A31N
0.743 0.0341
0.0179 0.0023 0.746
2.02 19.93 0.0093
0.406 0.00085
8.52 <0.0010
20.01 0.0206
0.407 <8.33 0.0040 0.0098
0.0026 0.0253
70.2 < 0.0040 0.005
1.95 SMAW 0.761 Electrodes 0.014(phase
19.65 3)0.412
67 0.0478 1.93 0.752 0.0440 0.0030 19.82 0.403 8.46 0.0021 0.0276 < 0.0040 0.0051 68.5
A32 0.0375 0.012 8.43 0.0040 0.0323 < 0.0040 0.005
68 0.0490 0.982 1.48 0.0255 0.0040No. 19.77 Alloy 0.408
AWS 8.55
Spec. 0.0035
Lot No. 0.0277
Cr <Fe0.0040Si 0.0043
Mn C 68.6
P
A33 0.0403 1.92 0.765 0.0121 0.0342 19.79 0.420 8.34 0.0042 0.0233 < S0.0040Nb 0.005
Ti
PM 54B 0.0166 0.612 0.440 0.0167 0.0324 i 17.89
152-A 2.82 11.85 < 0.0010 0.0345 < 0.0040 0.0064
ENiCrFe-7 98937 28.7 7.87 0.58 2.7 0.028 66.1
0.003 0.001 1.36 0.27
B1N 0.0361 0.091 0.734 0.0047 0.0013 20.40 0.413 8.60 < 0.0010 0.0003 < 0.0040 0.003
Type 316L 52B 0.0219 1.70 0.597 0.0187 0.0325 j 17.78 152-B 2.81 ENiCrFe-7
12.00 14633
0.0021 28.8
0.057 7.84
< 0.0040 3.15 0.028 64.8
0.48 0.0074 0.005 0.004 1.54 0.07
B2 0.0430 1.96 k0.760152-C0.0263 0.0124 N00170
ENiCrFe-7
19.69 0.412
28.5
8.38 0.0013 0.0235
8.73 0.393 4.53 0.038 0.005
< 0.00401.9910.007
0.002 0.1
94B1 0.0219 1.90 0.826 0.0162 0.0042 18.02 2.76 12.37 0.0062 0.0673 < 0.0040 0.0089 63.7
C1 0.0359 0.956 g 1.45152M-A 0.0117 0.0148 327781
ENiCrFe-7 19.83 0.423
29.2 8.40 0.36< 0.0010
7.77 0.0233
3.52 0.039 0.003 < 0.00401.690.004
0.001 0.08
12B1 0.0380 0.537 1.26 0.0277 0.0063 16.30 2.11 10.23 < 0.0010 0.255 0.0187 0.0055 68.8
h 152M-B ENiCrFe-7 17872 28.7 7.99 0.45 3.39 0.03 0.008 0.006 1.72 0.07
Plate Type 303 303b (303) 0.0501 0.503 0.3241.69 0.0296 17.44
152M-C 0.279 8.26 0.0036 0.0914 0.0096 0.0055
3.77 0.032 70.7
Weld parameters for GTAW l ENiCrFe-7 162663 28.8 7.96 0.48 0.011 0.003 1.79 0.06
308L 2L 0.0247 0.436 1.64 0.0193 0.0331 18.48 0.251 9.45 0.0024 0.0471 0.0047 0.0051 69.3
Clad Plate 4L 0.0185 0.428 1.68 0.0191 0.0047 19.13 0.249 9.90 0.0023 0.0409 0.0045 0.0053 68.3
308L-Si 1Si 0.0499 0.724 1.76 0.0287 0.180 18.31 0.184 8.80 0.0030 0.0717 < 0.0040 0.0056 69.5
Clad Plate 2Si 0.0336 0.938 1.63 0.0236 0.0426 17.88 0.0824 8.93 0.0039 0.0518 < 0.0040 0.0057 70.1
3Si 0.0321 0.968 1.64 0.0242 0.0242 18.04 0.0613 9.07 0.0039 0.0478 < 0.0040 0.0056 69.9
4Si 0.0272 0.996 1.66 0.0242 0.0160 18.30 0.0541 9.25 0.0045 0.0469 < 0.0040 0.0058 69.4
CASS CF8M J92 (pipe) 0.0484 0.552 1.13 0.0214 0.0191 20.93 2.57 11.72 0.0011 0.0336 0.0044 0.0075 62.8

© 2013 Electric Power Research Institute, Inc. All rights reserved. 33

 Bead Profile and Hot Crack Characterization

• Measured and recorded the following:

 Composite zone areas, toe angle(s), depth,
width, and penetration
• Calculated dilution by area method
• Inspected for cracks at 50x
• Cracks graded as follows:
 TNC – Total Number of Cracks > 0.2 mm 82 Bead on A31N sample
 TCL – Total Crack Length (sum of all
cracks)
 MCL – Maximum Crack Length (single
largest crack length)
 Cracks within d 0.2 mm proximity are
counted and sized as one crack
 Cracks categorization as:
– Surface Crack
– Midwall Crack 25x Micrograph 82 on A31N sample
– Fusion Line Crack

© 2013 Electric Power Research Institute, Inc. All rights reserved. 34

 Susceptibility Plot with Sulfur (GTAW – 2nd data set)

CF8A

© 2013 Electric Power Research Institute, Inc. All rights reserved. 35

 Susceptibility Plot with Silicon (GTAW – 2nd data set)

CF8A

© 2013 Electric Power Research Institute, Inc. All rights reserved. 36

 Maximum Crack Length vs Dilution (GTAW & SMAW)

© 2013 Electric Power Research Institute, Inc. All rights reserved. 37

 Dilution vs Silicon – Crack No Crack Plot
(GTAW & SMAW)

© 2013 Electric Power Research Institute, Inc. All rights reserved. 38

 S+P vs Si with Crack Free Region (GTAW Phase 1 &2)

© 2013 Electric Power Research Institute, Inc. All rights reserved. 39

 Crack Severity Chart (Phase 2 CASS-b Set)

Filler Metal 82 (F) 52i (E) 52M (B) 52 (N) 52MSS (M) Base Metal
Si S P Mn Mo Parameter No. 2 1 4 2 1 4 2 1 4 2 1 4 2 1 4 Crack Rank
1 1 2 1 1 A11N 0
1 2 2 1 1 A12 1 1
1 3 2 1 1 A13 1 1 2
2 1 2 1 1 A21N 1 1 1 3
2 2 2 1 1 A22 1 1 1 1 1 5
2 3 2 1 1 A23 1 1 1 1 1 5
3 1 2 1 1 A31N 1 1 1 1 1 1 6
3 2 2 1 1 A32 1 1 1 1 1 1 1 1 1 1 10
3 3 2 1 1 A33 1 1 1 1 1 1 1 1 1 9
1 1 2 1 1 B1N 0
3 3 3 1 1 B2 1 1 1 1 1 1 1 1 1 1 10
2 2 2 3 1 C1 1 1 1 1 4
Base Metal 1 8 9 0 6 6 0 6 6 0 3 4 0 1 5 Weld Metal
No. 18 12 12 7 6 Crack Rank

© 2013 Electric Power Research Institute, Inc. All rights reserved. 40

 Filler Metal Comparison Plot (Phase 2 CASS-b Set)

© 2013 Electric Power Research Institute, Inc. All rights reserved. 41

 Approach & Considerations to Prevent Hot Cracking

• Dilution Control
– GTAW keep dilution d 55% (52M, 52i, 52MSS, or 82)
– SMAW keep dilution d 35% (152 & 152M)
• Composition Control
– Use CMTRs to understand diluted composition
– Maintain following limits in weld deposit
S < 0.020 wt%; Si < 0.60 wt%; S+P < 0.035 wt%
– Consider effect of base metal S on dilution
– Consider influence of joint geometry and welding position
on dilution

© 2013 Electric Power Research Institute, Inc. All rights reserved. 42

 Approach & Considerations to Prevent Hot Cracking

• Process Parameter Controls

– Develop or identify optimum welding parameters and
techniques to minimize dilution
– The power ratio equation is a good method to
understand and control dilution for a given set of weld
and base metals
– Understand that parameters developed for low sulfur
base materials may be significantly different on higher
sulfur and higher silicon base materials

© 2013 Electric Power Research Institute, Inc. All rights reserved. 43

 Approach & Considerations to Prevent Hot Cracking

• Bead Placement Control and Buffer Layers

– Use bead placement to minimize dilution

– Buffer may be ER309L, ER308L

– Data shows 52MSS may be good buffer layer choice
– Data shows 82 is not a good buffer layer choice
– Mo bearing buffer layers currently under investigation

© 2013 Electric Power Research Institute, Inc. All rights reserved. 44

 Future Work and Testing

• Use Design of Experiments (DOE) to define future

testing
– Select Mo as target element for study
– Use data for input to new filler metal development
• Continue testing on 2nd set of CASS samples
– This set provides desired fidelity of Si & S compositions
that was not achieved in 1st sample set
• Investigate GTAW with magnetic arc stirring on CASS
samples
• Investigate CMT low dilution process

© 2013 Electric Power Research Institute, Inc. All rights reserved. 45

 Questions or Comments?

Welding and Repair Technology Center

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 Together…Shaping the Future of Electricity

© 2013 Electric Power Research Institute, Inc. All rights reserved. 47