Calculation Method of Material Mechanical Properties of Dissimilar Metal Welded Joint Based on Indentation Response

Based on the Hollomon constitutive model, the relationship between different mechanical property parameters of materials (yield stress and strain hardening index) and the indentation response parameters (loading curvature and loading index) of the loading section of the load-displacement curve was analyzed by indentation test simulation by ABAQUS finite element analysis software and the method of controlling single variable. The prediction formula of the mechanical property parameters of the materials derived from the response parameters of the loading section was established, and the yield stress and strain hardening index entered in the finite element analysis were used as the conventional truth values to verify the accuracy of the prediction method. The material mechanical property parameter distribution of SA508 steel/52M alloy surfacing layer/52M alloy butt weld/316L steel dissimilar metal welded joint was obtained by this prediction method. The results show that the absolute relative errors of yield stress and strain hardening index calculated by the prediction formula were 10.5% and 6.29%, respectively. The formula could accurately predict the material mechanical property parameters of the local area of the dissimilar metal welded joint. The yield stress and strain hardening index of the heat affected zone on both sides of the dissimilar metal welded joint by calculation changed obviously, and the yield stress decreased while the strain hardening index increased with the increase of the distance from the fusion line. The yield stress and strain hardening index distribution of base metal and 52M alloy surfacing layer and butt weld were relatively stable.