Effect of laser shock peening on high cycle fatigue properties of aluminized AISI 321 stainless steel

•Laser shock peening (LSP) was applied to aluminized 321 stainless steel.•High fraction twinning and compressive residual stress were induced by LSP.•More obvious de-twinning occurred in LSP sample during cyclic deformation.•Dynamic recovery is fully developed in LSP sample during cyclic deformation.•Fatigue lives are increased by 204.4–230.8% though LSP treatment. In this work, the effect of laser shock peening (LSP) treatment on fatigue property of aluminized AISI 321 stainless steel was studied. The high fraction twinning and compressive residual stress (CRS) induced by LSP at the severe plastic deformation (SPD) layer were found to be responsible for the enhanced fatigue property. De-twinning was conspicuously noticed in LSP sample. Moreover, the dynamic recovery (DRV) was only noticed at SPD layer during cyclic deformation related to CRS. In sum, the aluminized stainless steel achieved an enhanced fatigue property by LSP treatment.