Effect of Laser Shock Peening without Coating on Grain Size and Residual Stress Distribution in a Microalloyed Steel Grade

This study aimed to identify the optimal combination of wavelength and laser pulse density achieve pressure that can induce maximum compressive residual stress at subsurface microalloyed steel. For this, shock peening without coating (LSPwC) was performed on steel samples fundamental (1064 nm) with densities 3, 6, 9, 12 GW/cm2 second harmonic (532 9 GW/cm2. The distributions were studied a depth 500 µm in laser-treated samples. Tensile observed surface laser-peened specimens both conditions 532 nm). significant impartment across achieved attained 1064nm condition. optical micrographic analysis regions LSPwC specimen 1064 nm shows evidence high degree plastic deformation. Electron backscatter diffraction (EBSD) there is grain refinement due deformations subjected wavelength. Microhardness distribution region work-hardening effects laser-processed also an indication thermal softening effect treated wavelength, it correlated lower depth.