Laser Cutting of Circular Holes in AISI 304 Stainless Steel Sheet: Heating, Diffusion and Stress Analyses

Due to high melting point and low viscosity of molten oxides formed during cutting of stainless steel, laser cutting offers considerable advantages over the conventional cutting methods. In general, high pressure N-2 assisting gas is used coaxially with the laser beam during cutting process, which in turn forms nitrides. The use of N-2 in the cutting section prevents high temperature exothermic oxidation reactions in laser irradiated kerf surfaces. In the present study, laser gas-assisted cutting of small diameter holes in thin sheets of AISI 304 stainless steel is carried out. Temperature and stress fields and N-2 diffusion in the cutting zone are predicted using finite element method (FEM). The simulation conditions are selected in-line with the experimental parameters, with an experiment being carried out to assess the geometric features of the cut surfaces. The morphological and microstructural changes in the cut sections are examined using an optical microscope, a scanning electro