Wear Resistance of AISI 5140 Steel with Micro-laser Shock Peening

AISI 5140 steel is widely used in automobile steering shafts, whereby its abrasion resistance directly affects the reliability of transmission components. This paper proposes Micro-laser shock peening (Micro-LSP) as a new laser shock peening (LSP) treatment. The surface of the AISI 5140 steel was examined after Micro-LSP, and its in-fluence on the wear resistance was determined. Compared with LSP, Micro-LSP exhibited a better strengthening effect on the wear and surface hardness. After Micro-LSP treatment, the surface hardness of the sample was 368.7 HV0.5, the depth of the hardened layer was 580 mu m, and the surface roughness was 1.40 mu m. This improved wear resistance is attributed to the higher microhardness and formation of a surface oxide layer.