Severe shot peening: A promising solution for mitigating stress corrosion cracking in solution-annealed LPBF 316 l stainless steel

Abstract

Laser powder bed fusion (LPBF) effectively fabricates intricate 316L stainless steel components but often results in significant tensile residual stresses and anisotropic microstructures, compromising mechanical performance. Solution annealing at 1050–1100 °C reduces anisotropy along with mitigating these stresses but may reduce stress corrosion cracking resistance (SCC). Therefore, this study combined solution annealing with severe shot peening (SSP) to enhance the surface properties and the SCC performance. The results showed that SSP introduced compressive residual stresses exceeding −700 MPa on the surface and up to 300 µm in depth, significantly reducing tensile stresses. Additionally, SSP increased surface hardness and halved surface roughness, potentially enhancing stress corrosion cracking resistance and mechanical performance, establishing SSP as an effective post-processing technique for LPBF 316L components.