finite element modeling of heat transfer in pulsed laser welding of similar and dissimilar carbon and stainless steels

Laser welding is one of the most prominent manufacturing methods in various industries due to its speed and high quality. the laser beam welding process has two modes of conduction and keyhole. the keyhole mode is more attractive due to its greater penetration depth and smaller heat-affected zone.  to achieve the keyhole mode, it is necessary to adjust the welding process variables, which requires many experiments. hence, simulation can be used as a powerful tool to reduce the cost. in this study, similar and dissimilar lap joints of low-carbon steel and stainless steel using pulsed laser welding were simulated by finite element software ansys. the effects of pulse energy and frequency were examined and the values for obtaining the keyhole mode were determined. simulated weld pool dimensions were compared to experimental results and the good agreement between them showed that the model is appropriate for simulating pulsed laser welding. numerical results showed that the keyhole mode is created in dissimilar joints of low-carbon steel and stainless steel, similar joints of stainless steel, and similar joints of low-carbon steel at pulse energies of 17.1, 11.8, and 13.9 j, respectively.  a pulse frequency of 14 hz was found to be the optimal condition for the formation of the keyhole.