Influence of yield strength of weld metal on prediction accuracy of welding residual stress in SM490A steel joint

Based the commercial software MSC.Marc, a thermal elastic plastic finite element method was developed to simulate welding temperature and residual stress fields. By using moving heat source and the temperature-dependent thermo-physical and mechanical properties of the base metal (SM490A) and weld metal (YGT50), the welding residual stress distribution in a single-pass bead-on joint was calculated by means of the developed computational approach. Meanwhile, the influence of the weld yield strength on the peak and distribution of welding residual stresses was discussed. The results show that the yield strength of weld metal has a significant influence on the longitudinal residual stress in overmatched joint. When the yield strength of weld metal was assumed to be the same with that of base metal, the finite element model will underestimate the welding residual stress in the weld zone. If the yield strengths of weld metal measured by experiment were used in fusion zone, the predictions of longitudinal residual stress agrees well with that of experiments.