Numerical simulation and experimental analysis of simultaneous melting and burnishing of 304 stainless steel with oscillatory laser heat source

In this paper the simultaneous laser melting and burnishing of a stainless steel is studied both experimentally and theoretically. A continuous CO2 laser beam is moving either along a straight line or criss-crossing it. It has been shown that the oscillatory movement of the laser source together with the burnishing results in a better surface topography comparing to the non-oscillatory process. A theoretical modelling is applied to calculate the temperature field during the process. The results of theoretical analysis are verified by analyzing microstructure changes of the material in laser heated zone. It has been found that a very good agreement between theoretical and experimental results is achieved when the change of the absorptivity of the laser beam with the temperature of the melted zone is taken into account. K e y w o r d s: laser treatment, hybrid treatment, surface structure, mathematical modelling