S355 steel is a low alloy steel,which is accompanied by solid phase transformation during welding. Based on the solid phase transformation effect of S355 steel,a thermal-stress finite element model of welding process was established.The microstructure evolution law in the weld and heat affected zone was analyzed. The results show that under the effect of solid phase transformation,the Mises stress of the weld decreased. The residual stress and deformation evolution curves of the heat affected zone with and without phase transformation were compared. The calculated residual stress was in good agreement with the measured value.
S355 steelsolid state transformationmicrostructureresidual stress