Texture morphologies and residual stresses due to laser surface texturing on the 304 stainless steel

Laser surface texturing (LST) has emerged as a cost-effective and environmentally friendly technique that is widely used to achieve the desired surface modification for a range of materials. The efficiency of LST depends strongly on the resulting surface morphology of textures and residual stresses near the surface of components. Because of the tiny dimensions, it is currently challenging to determine the residual stresses within the texture and along the depth direction using experimental methods. In this work, an attempt was made to numerically investigate the LST process on the 304 stainless steels by applying a nanosecond pulsed laser irradiation. Based on the finite element method, the temperature field, texture morphology and residual stresses were estimated during the LST process. The effects of various laser parameters such as spot size, pulse energy, pulse width, processing number, and scanning speed were analyzed, emphasizing the distinction between single-pit and groove-type textures. Results showed that the estimated tensile stresses are dominant in the surface and nearsurface regions, with stress concentrations at the outer texture edges. The estimated maximum tensile stress can reach 633.8 MPa and the retative error is about 13.4 % in comparison with the experimental value.