HAZ and Melt Limits of 3-D CO2 Laser welding


An analytical and numerical 3-D model for keyhole CO2 laser welding of thick C/Mn steel sheets is constructed to study the heat affected zone (HAZ) and melt limits. Simulation results are compared with experimental investigations under variety of laser material processing conditions. The model combines a moving point source for the top part of the weld and a moving line source for the parallel sided region of the weld. The good match of theoretical and experimental results makes the model a good tool to predict the HAZ volume in which microstructure changes may occur. Such prediction is useful in the investigation of hardening and the cracks formation during laser welding.