Simulation of laser butt welding of AISI 316L stainless steel sheet using various heat sources and experimental validation

The thermo-elasto-plastic analysis of type 316L stainless steel sheets during pulsed Nd-YAG Laser-beam welding was carried out using three different heat sources employing SYSWELD. The three heat sources employed were 3D conical, 3D conical with double ellipsoidal and 3D conical with cylindrical shell. The simulated thermal cycles, residual stresses and distortion were validated by experiments. The simulated thermal cycles were validated by thermal cycles measured using thermocouples at pre-defined positions. The simulated residual stress profiles were validated by residual stress profiles measured using ultrasonic technique (UT). The simulated distortion values were validated by distortion measured using vertical height gauge. There was good agreement between the model predictions and experimental measurements. It was found that the model using 3D conical with cylindrical shell heat source predicted the thermal cycles, residual stresses and distortion more accurately compared to that of the other heat sources.