Influences of local PWHT from different criteria at home and abroad on the residual stress of the under-matching welded joint

Abstract

The under-matching welded joint is more commonly used in engineering practice now and the post-weld heat treatment (PWHT) is the common method to reduce the residual stress of the welded joint, while the research on the under-matching welded joint after PWHT is few. And the different influences of the local PWHT from different criteria haven't been specifically analyzed by the researcher. The finite element software-ABAQUS is used to simulate the welding process and PWHT process of the under-matching welded joint which is the combination of CF62(base metal) and 316L(weld) in this paper. The discussion of the influences of local PWHT from different criteria at home and abroad on the residual stress of the under-matching welded joints are based on the experimental verification and the proposal criterion has been given in this paper. The numerical simulation by finite element has been proved to be useful to predict the residual stress of the under-matching welded joint after local PWHT from different criteria by the comparison between residual stress results of experiment test and numerical simulation in this paper. The local PWHT method of ASME-Ⅷ is the best and it is recommended in this paper. The criteria PD5500 and EN13445 are at the second place while the old criterion GB150-1998 is conservative. The new criterion GB150-2011 have been promoted very much than the old criterion GB150-1998 of the local PWHT method.