Numerical and experimental study on the effect of post- weld heat treatment parameters on the relaxation of welding residual stresses

摘要

In this paper, numerical and experimental studies are conducted to investigate the effect of post-weld heat treatment (PWHT) parameters, including holding time and temperature, on the distribution of welding residual stresses. The selected material is AISI type 304 austenitic stainless steel in the form of a pipe, for which the determination of heat treatment parameters is complicated by the risk of intergranular corrosion. The study includes experimental measurements of residual stresses both before and after PWHT of the pipe, and creep and tensile tests to determine the viscoplastic behaviour and mechanical strength of the material. Good agreement between experimental measurements and numerical predictions is obtained; therefore, further simulations were performed to study the effect of variation of heat treatment parameters on the relaxation of welding residual stresses.