Study on Shot Peening Effect of Nitrocarburized Material

Abstract

The authors investigated their characteristics and the strength of NH materials treated by Double Shot Peening (DSP). The results obtained are summarized as follows : (1) Increased diffusion layer hardness between the surface and depth of 400μm by DSP (2) Remarkably high residual stresses of surface residual stress with -701MPa and maximum compressive residual stress with -733MPa of the NH+DSP material (3) Considerably increased fatigue limit of the NH+DSP material. 33% (stress ratio R≧0) and 28% (R=-1) higher fatigue limit than the NH materials, respectively.