FEM Simulation of Pulsed Laser Welding of High-Carbon Alloy Steel: Using Different Heat Source Models

High-strength alloys can be efficiently welded utilizing laser beam welding because of their attributes, such as minimized fusion, heat-affected zone extensions, and minor deformation. Computational study of the laser material interaction process assists in analysing numerous process variables and their effect, which is challenging experimentally. This work developed a 3D numerical model for pulsed laser welding of high-carbon alloy steel. A hybrid 3D conical heat source model with a double ellipsoid and a 3D conical heat source model was employed to study laser–material interaction in the finite element modelling of the process. Post-processing of the simulation results for both the heat sources was compared to investigate the suitability of the volumetric heat source depicting experimental data. The analysis was carried out by comparing the models and calculating the dimensions of weld geometry for various process parameters. A suitable heat source for the weld geometry was identified using the isotherms. Commercial software (Comsol Multiphysics 5.6) is used to solve the conduction and heat flux equations using Finite Element Methods. By altering the welding speed at three different peak powers, the weld pool depth and width were calculated. The results were plotted and matched with the experimental data for the two different heat sources. Finally, the heat sources were compared to obtain the laser peak power for full-depth penetration of the weld joint. The simulations were further validated by comparing the experimental results of weld geometry at different laser peak power.