Influence of Laser Parameters on Residual Stress Field of AISI 304 Stainless Steel Induced by Laser Peening: A Finite Element Analysis

The present paper established a non-linear elastic-plastic finite element method to predict the residual compressive stress distribution induced by Laser Peening (LP) in the AISI 304 stainless steel. The two dimensional FEA model considered the dynamic material properties at high strain rate (10⁶/s) and the evaluation of loading conditions. Effects of laser power density, laser spot size, laser pulse duration, multiple LP processes and one/two-sided peening on the compressive stress field in the stainless steel were evaluated for the purpose of optimizing the process. Numerical results have a good agreement with the measurement values by X-ray diffraction method and also show that the magnitude of compressive stress induced by laser peening is greater than the tensile welding residual stress. So, laser peening is an effective method for protecting weldments against stress corrosion crack. The above results provide the basis for studying the mechanism on prevention of stress corrosion cracking in weld joint of type 304 stainless steel by laser peening.