Laser Heating of Tungsten Carbide-Coated Steel Surface: Influence of Coating Thickness on Temperature Field and Melt Depth

摘要

Laser repetitive pulse heating of tungsten carbide coating formed at a steel sheet surface is examined. Temperature field and melt pool formed in the coating and steel sheet are simulated for different coating thicknesses. The influence of laser power intensity distribution on the melt pool formation is incorporated in the analysis through introducing the laser pulse parameter. The control volume method is used to predict temperature field while the enthalpy-porosity method is incorporated to account for the phase change during the heating process. It is found that temperature predictions at the coating surface agree with the thermocouple data. The melt pool width formed in the coating is smaller than that corresponding to the steel sheet. Increasing coating thickness reduces the peak temperature at the surface. The Marangoni flow results in a toroid shape of rotating cells in the melt pool of the coating.