Generation Behavior of Thermal and Residual Stresses Due to Phase Transformation During Welding Heat Cycles

Weld residual stress is possible to be controlled by considering and changing mechanical properties of the materials. History of thermal stress due to phase transformation and residual stress during welding heat cycles is studied in order to investigate the generating mechanism of residual stress and the effects of material properties on stress generation. Two materials of high-tensile strength steels are used in the numerical simulation and experiment. Material property of each microstructural phase is used and the time- and temperature-dependant proportion of microstructure are considered by using CCT-diagram in the analysis. Thermal stress history obtained by the simulation agrees well with the experimental result during welding heat cycles.