Surface Integrity and Anti-fatigue Mechanism of 30CrMnSiNi2A Steel with Shot Peening Treatment

摘要

In this study, 30CrMnSiNi2A steel specimens were treated by shot peening technique. In order to evaluate the effects of shot peening process on the surface characteristics, the surface topography and roughness of the treated and untreated specimens were observed and analyzed using scanning electronic microscope (SEM) and surface profile tester. Surface microstructure and residual stress were observed and analyzed using transmission electron microscope (TEM) and X-ray stress apparatus respectively. Results show that the surface roughness of milling specimens could be reduced from Ra 4.45 urn to 2.39 urn using shot peening process. Severe plastic deformation and grain refinement were also induced by the process, and the average grain size of nano-structured regime was about 46 run. Moreover, a 300 μm compressive residual stress layer with the -766.5 MPa compressive residual stresses was induced. At the same time, the anti-fatigue mechanism of shot peening was discussed.