Rolling contact fatigue and damage characteristic of AISI 9310 steel with pre-laser shock peening treatment

• 1Laser shock peening (LSP) induced a gradient layer with compressive residual stress and work hardening. • 2LSP induced smaller Kernel Average Misorientation and improved plastic deformation resistance. • LSP brought a transforming trend from ductile fracture to brittle fracture for AISI 9310 steel. • Rolling contact fatigue life of AISI 9310 steel after LSP was significantly improved, from 5.37 × 10 5 cycles to 9.04 × 10 5 cycles. Contact fatigue is one of the most common failure modes for gear tooth, which is closely associated with the material surface state. In this paper, the specimens with and without pre-LSP treatment were subjected to rolling contact fatigue (RCF). The surface damage morphology/ characteristics and fracture morphology were characterized. The results showed that RCF life was improved from 5.37 × 10 5 to 9.04 × 10 5 cycles after LSP treatment. The main reasons are the effect of the work hardening and compressive residual stress induced by LSP. A smaller Kernel Average Misorientation value with pre-LSP treatment at subsurface after RCF, resulting in the increase of plastic deformation resistance and RCF life.