MULTI-BEAM LASER HEATING OF STEEL: TEMPERATURE AND THERMAL STRESS ANALYSIS

Laser multi-beam heating of steel sheet surface is considered. The irradiated laser spots are located along an arc to increase heated surface area during laser scanning at a constant speed. Temperature and stress fields are predicted for various number of spots along the arc. It is found that temperature and stress fields in the irradiated substrate can be controlled through proper selection of the number of irradiated spots along the arc. Increasing number of irradiated spots results in development of almost uniform high temperature and high stress fields around the arc; however, local heating and discontinuous stress field giving rise to large differences in von Mises stress occurring for reduced number of spots in the arc.