A simplified energy-based model for laser welding of ferritic stainless steels in overlap configurations

A theoretical model is developed for predicting the weld shape produced by a Continuous Wave (CW) Nd:YAG laser in a constrained overlap configuration on a ferritic stainless steel, and verified by means of experiments. Tests demonstrate that, as assumed in the modelling phase, penetration depth is linearly dependent on the energy density input, within the hypothesis of conduction dominated welding. Penetration depth determines the weld resistance length at the interface since the weld profile is found to change from approximately semicircular to parabolic when the energy density input is varied in the range from 22 J/mm2 to 32 J/mm2.