Assessing the Residual Stresses in Dissimilar Welded Joint: Depth-Sensing Indentation Testing and Numerical Simulation

In this study, both the depth-sensing indentation (DSI) measurements and finite element (FE) simulations were performed to investigate the residual stress distribution in the Super304H/T92 dissimilar welded joint with Ni-based filler metal. To measure the residual stresses using the DSI technique, the stress-relieving annealing method was adapted for the welded joint to obtain the in-situ reference curves corresponding to the as-welded state. The distribution of the residual stress across the welded joint was then obtained using Suresh-Atar model combined with the DSI measured results, and the results were in good agreement with the measured results by XRD. Besides, pile-up and sink-in phenomena were observed in the residual indentation morphologies. It is found that the dispersion of local residual stresses was related to the heterogeneous microstructures. To further understand the formation causes of the measured residual stress distribution, a thermal-metallurgical-mechanical finite element analysis was also performed in this study. It was suggested that the combined effects of structural size and material properties may be responsible for the measured residual stress distribution. The research work of this paper would further extend the applications of the DSI technique in the welding residual stress testing field.