Finite element and experiment analysis of welding residual stress in S355J2 steel considering the bainite transformation

This paper investigated the residual stress distribution and evolution in single-pass bead-on-plate TIG welding of S355J2 steel using the coupled thermo-metallurgical-mechanical model. The metallurgical calculation was based on parameterizing the continuous heating transformation and continuous cooling transformation diagrams. The simulated phase fraction in welding joints was validated against the dilatometric curves. The predicted results of welding residual stress revealed that the solid-state phase transformation incorporating undercooling austenite and transformation strain had significant consequences on the welding residual stress. The residual stress measurement was obtained by the XRD and relaxation methods. The good agreements between the simulated and experimental results indicated that the undercooling austenite and the bainitic transformation strain were crucial for predicting welding residual stress. The accurate thermo-metallurgical-mechanical model contributed to controlling the residual stress distribution reasonably by numerical method.