文献类型：期刊文献

英文题名：Research on reheat cracking criterion of CGHAZ in 2.25Cr1Mo0.25V steel

作者：Liu, Chang-Jun[1]; Zhou, Shuang[1]; Tan, Jian-Ping[1]; Zhang, Hao-Yu[1]

机构：[1] Key Laboratory of Safety Science of Pressurized System, Ministry of Education, East China University of Science and Technology, Shanghai, 200237, China

年份：2018

卷号：1B-2018

外文期刊名：American Society of Mechanical Engineers, Pressure Vessels and Piping Division (Publication) PVP

收录：EI(收录号：20184706128086)

语种：英文

外文关键词：Ternary alloys - Heat affected zone - Molybdenum steel - Welding - Numerical methods - Chromium alloys - Textures - Chromium steel - Creep - Stress relaxation

摘要：During the final post welding heat treatment (PWHT), residual stress relieves gradually with the accumulation of creep strain. However, reheat cracking with intergranular characteristic will occur when grain boundary cannot accommodate this kind of strain for some special steel welding, such as the welding coarse grained heat affected zone (CGHAZ) of 2.25Cr1Mo0.25V steel. Based on the principle of stress relaxation similar to the process of PWHT, two methods are applied to study the strain criterion of reheat cracking. Stress relaxation testing is performed on CGHAZ materials prepared by Gleeble thermomechanical simulator. The critical strain is calculated using the relationship between stress reduction and creep deformation. Self-loaded notched C-ring specimens are tested taken from the welding structure, coupled with finite element modeling and multiaxial creep coefficient to determine the critical strain. The results show that there is a large numerical difference between the critical strains from two methods. The possible reasons for the difference are given. Regarding the PWHT as a service process, whether the critical strain values obtained exceed the strain limits in ASME-NH is discussed. Copyright ? 2018 ASME.