Please use this identifier to cite or link to this item:
|Title: ||Microstructure and Stress Corrosion Cracking Behavior of the Weld Metal in Alloy 52-A508 Dissimilar Welds|
|Authors: ||Wei-Chih Chung;Jiunn-Yuan Huang;Leu-Wen Tsay;Chun Chen|
|Contributors: ||NTOU:Institute of Materials Engineering|
|Keywords: ||A508 steel;Alloy 52 ﬁller metal;dissimilar welds;microstructures;stress corrosion cracking;high-temperature water|
|Issue Date: ||2011-10-20T08:07:36Z
|Publisher: ||Materials Transactions(The Japan Institute of Metals)|
|Abstract: ||abstract:In the nuclear power industry, dissimilar metal welding is widely used for joining low alloy steel to austenite stainless steel components
with nickel-base ﬁller metals. In this study, attention was paid to the weld metal in multi-pass Alloy 52-A508 dissimilar welds. An approximately 2 mm wide transition zone was observed that consisted of a martensitic layer (1020um) along the weld interface and the austenite phase region with varying degrees of dilution. After post-weld heat treatment, the microstructures near the weld interface consisted of martensite, carbides and Type II boundaries. The presence of Type II boundaries signiﬁcantly reduced the resistance to stress corrosion cracking (SCC) and formed intergranular cracking under simulated reactor coolant conditions. Constant extension rate tensile (CERT) tests were performed on the notched tensile specimens in 300 C water at two extension rates, 3104 and 1106 mm/s. A fast CERT test can be
regarded to have no contribution of corrosion, and its results can be used as standards for comparison. In the slow CERT tests, the ductility losses of round-bar specimens with a circumferential notch at various regions in the weld metal were ranked accordingly. The relative susceptibility to SCC in terms of the ductility loss in increasing order of severity was as follows: the undiluted weld metal, the transition zone and the weld interface. SEM fractographic observations were consistent with the SCC results, i.e., an increased ductility loss or SCC susceptibility was associated with more brittle fractures.
|Relation: ||52(1), pp.12-19|
|Appears in Collections:||[材料工程研究所] 期刊論文|
Files in This Item:
All items in NTOUR are protected by copyright, with all rights reserved.