The residual stress relief of post weld heat treatment in SMA490BW welded joints: Simulation and experiment

The effects of post-weld heat treatment (PWHT) parameters on residual stress release and mechanical properties of SMA490BW steel were investigated by mechanical experiments and finite element analysis. The creep behavior of the SMA490BW steel at high temperatures (500–600 °C) has been described numerically by implementing the Norton-Bailey model. The mechanical performance of two distinct PWHT schemes was studied as well as the residual stress relief mechanism. The simulation results reveal that the evolution of the equivalent creep strain contributes to the residual stress relief in the welded joint, and the longitudinal and transverse residual stresses are reduced by about 65%. In the case of the PWHT holding temperature equal to 600 °C, the hardness of the weld metal decrease from 200 H V for 1 h to 190 H V for 2 h. The PWHT holding time has no remarkable effect on the ultimate tensile strength of the joint, which is reported to be 495 MPa for 1 h and 502 MPa for 2 h. • A Norton-Bailey model is built into PWHT simulation of SMA490BW Steel. • Equivalent creep strain is the mechanism by which PWHT relieves residual stress. • The ultimate strength of PWHT 1 h is approximately the same as that of PWHT 2 h. • The improved PWHT process with a short holding time could save 40% energy consumption.