Numerical Simulation of Oxidation Effects in the Laser Cutting Process

A numerical model is developed for the process of oxygenassisted laser cutting of mild steel. Coupled oxygen concentration and energy balance equations are solved by a controlvolume-based computational scheme, while the velocity field is obtained by analytical boundary theory. The enthalpy method is adopted to trace the free boundary of the phase change and thus determine the molten-layer thickness. The steady-state simulation results include the temperature and oxygen concentration profiles at the cut front, the effects of impurity gas on the cutting speed, reaction energy, conduction loss and heat affected zone. The striation phenomenon is studied and the temperature fluctuation range versus cutting speed and oxygen pressure shows similar trends to the experimental results.