Abstract

In this paper, a minimum toughness assessment method of exempting postweld heat treatment (PWHT) based on the master curve method is proposed to replace the current method of determining whether to perform PWHT by material thickness. Reference temperature to prevent fracture (T0-required) for structure to be exempt from PWHT at minimum design metal temperature (MDMT) was obtained by using the master curve method under presumed stresses and flaw size. A series of exemption curves were generated for the steels used in pressure vessels with yield strength of 300∼550 MPa, and the method was corrected for low-stress conditions. Then the feasibility of this method was verified by an engineering example. A SA-738Gr.B welded joint in the example was taken as the research object, the experiment showed that the weld metal was the worst part of the fracture toughness of the joint. The results of research objects which were exempted from PWHT by the proposed method are consistent with ASME Code Case N-841, which proves that this method is feasible in assessing the exemption from PWHT.

References

1.
Smith
,
C.
,
Pistorius
,
P. G. H.
, and
Wannenburg
,
J.
,
1997
, “
The Effect of a Long Post Weld Heat Treatment on the Integrity of a Welded Joint in a Pressure Vessel Steel
,”
Int. J. Pressure Vessels Piping
,
70
(
3
), pp.
183
195
.10.1016/S0308-0161(96)00029-4
2.
Olden
,
V.
,
Kvaale
,
P. E.
,
Simensen
,
P. A.
,
Aaldstedt
,
S.
, and
Solberg
,
J. K.
,
2003
, “
The Effect of PWHT on the Material Properties and Micro Structure in Inconel 625 and Inconel 725 Buttered Joints
,”
ASME
Paper No. OMAE2003-37196.10.1115/OMAE2003-37196
3.
Withers
,
P. J.
,
2007
, “
Residual Stress and Its Role in Failure
,”
Rep. Prog. Phys.
,
70
(
12
), pp.
2211
2264
.10.1088/0034-4885/70/12/R04
4.
Wu
,
X. R.
,
1984
, “
The Effect of Welding Residual Stress on Brittle Fracture of Plates With Surface Cracks
,”
Eng. Fract. Mech.
,
19
(
3
), pp.
427
439
.10.1016/0013-7944(84)90003-1
5.
Matos
,
C. G.
, and
Dodds
,
R. H.
Jr.
,
2001
, “
Probabilistic Modeling of Weld Fracture in Steel Frame Connections Part I: Quasi-Static Loading
,”
Eng. Struct.
,
23
(
8
), pp.
1011
1030
.10.1016/S0141-0296(00)00107-3
6.
Aloraier
,
A.
,
Al-Mazrouee
,
A.
,
Price
,
J.
, and
Shehata
,
T.
,
2010
, “
Weld Repair Practices Without Post Weld Heat Treatment for Ferritic Alloys and Their Consequences on Residual Stresses: A Review
,”
Int. J. Pressure Vessels Piping
,
87
(
4
), pp.
127
133
.10.1016/j.ijpvp.2010.02.001
7.
Paddea
,
S.
,
Francis
,
J. A.
,
Paradowska
,
A. M.
,
Bouchard
,
P. J.
, and
Shibli
,
I. A.
,
2012
, “
Residual Stress Distributions in a P91 Steel-Pipe Girth Weld Before and After Post Weld Heat Treatment
,”
Mater. Sci. Eng. A: Struct. Mater. Prop. Microstructure Process
,
534
(
0
), pp.
663
672
.10.1016/j.msea.2011.12.024
8.
Aydin
,
H.
,
Bayram
,
A.
, and
Durgun
,
I.
,
2010
, “
The Effect of Post-Weld Heat Treatment on the Mechanical Properties of 2024-T4 Friction Stir-Welded Joints
,”
Mater. Des.
,
31
(
5
), pp.
2568
2577
.10.1016/j.matdes.2009.11.030
9.
Singh
,
A. K.
,
Debnath
,
T.
,
Dey
,
V.
, and
Rai
,
R. N.
,
2015
, “
A Study on Effect of Preheating and Post Weld Heat Treatment (PWHT) of Grade P91 Steel
,”
J. Mater. Sci. Mech. Eng.
,
2
(
8
), pp.
57
62
.https://krishisanskriti.org/vol_image/08Jul201510075310%20%20%20%20%20%20%20%20Akhilesh%20Kumar%20Singh%20%20%20%20%2057-62.pdf
10.
Pimenta
,
G.
, and
Bastian
,
F.
,
2002
, “
Influence of Plate Thickness on the Mechanical Properties of Welded Joints Subjected to Long-Term Post Weld Heat Treatments
,”
J. Mater. Eng. Perform.
,
11
(
2
), pp.
130
137
.10.1361/105994902770344187
11.
Abson
,
D. J.
,
Tkach
,
Y.
,
Hadley
,
I.
,
Wright
,
V. S.
, and
Burdekin
,
F. M.
,
2006
, “
A Review of Postweld Heat Treatment Code Exemptions
,”
Weld. J.
,
85
(
3
), pp.
63
69
.http://www.chte.org/d/file/2013-01-07/fe7979afe598645c9249a62a185d99fa.pdf
12.
Denney
,
A. K.
, and
Barraclough
,
C. H.
,
1996
, “
Design Approaches for Avoiding PWHT of North Sea Offshore Platforms
,”
Proc. 15th International Conference on Offshore Mechanics and Arctic Engineering
,
Hemisphere New York
, Vol. 3, p.
323
.https://www.osti.gov/biblio/403626
13.
Watanabe
,
N.
,
Sakai
,
Y.
,
Hayashi
,
K.
,
Higashikubo
,
T.
,
Satou
,
M.
, and
Iida
,
K.
,
1992
, “
Study on the Application of 50 mm Thick Welded Joints Without PWHT for Containment Vessels
,”
Proc. 7th Internationale Konferenz ueber Druckbehaeltertechnologie
, Duesseldorf, Germany, Vol. 2, pp.
1124
1139
.https://inis.iaea.org/search/searchsinglerecord.aspx?recordsFor=SingleRecord&RN=24044305
14.
Hayashi
,
T.
,
Kim
,
C. C.
,
Kumagai
,
K.
,
Goto
,
M.
, and
Otake
,
S.
,
2017
, “
Technical Basis for the Exemptions to Mandatory Post Weld Heat Treatment (PWHT) of SA-738 Grade B for Sec. III Div. 1 Subsection NE Application
,”
ASME
Paper No. PVP2017-65694.10.1115/P VP2017-65694
15.
Wallin
,
K.
,
2010
, “
Structural Integrity Assessment Aspects of the Master Curve Methodology
,”
Eng. Fract. Mech.
,
77
(
2
), pp.
285
292
.10.1016/j.engfracmech.2009.02.010
16.
GB/T 34019
,
2017
,
Ultra-High Pressure Vessel
,
Standardization Administration of the People's Republic of China
,
Beijing, China
.
17.
Newman
,
J. C.
, and
Raju
,
I. S.
,
1981
, “
An Empirical Stress-Intensity Factor Equation for the Surface Crack
,”
Eng. Fract. Mech.
,
15
(
1–2
), pp.
185
192
.10.1016/0013-7944(81)90116-8
18.
Shi
,
Y. W.
,
1993
, “
Prediction of Fracture Toughness Requirement for Engineering Structures
,”
Eng. Fract. Mech.
,
46
(
2
), pp.
285
289
.10.1016/0013-7944(93)90289-5
19.
Starova
,
L. L.
,
Koval'chuk
,
V. G.
,
Borisov
,
M. T.
,
Lukin
,
V. I.
, and
Golev
,
E. V.
,
2006
, “
A Filler Material for Welding High-Strength, Structural Alloyed Steels
,”
Weld. Int.
,
20
(
2
), pp.
137
140
.10.1533/wint.2006.3583
20.
Zhang
,
Y. L.
,
Hui
,
H.
,
Zhou
,
Z. Q.
, and
Cong
,
X. C.
,
2019
, “
Study on Fracture Toughness Evaluation Method of SA-738Gr.B Steel Heat Affected Zone in Ductile-Brittle Transition Region
,”
J. Nucl. Sci. Technol.
,
56
(
6
), pp.
503
512
.10.1080/00223131.2019.1598305
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