Influence of Shot Peening on the Bending Fatigue Performance of TM210A Steel

To enhance the fatigue performance of the new TM210A steel and analyze the influence of shot peening on such properties. The surface test was used to analyze the effects of shot peening on surface morphology, roughness and residual stress, and rotational flexural fatigue tests were carried out to observe fatigue fracture morphology and analyze fatigue performance of the base material and shot-peened specimen. After shot peening, the surface of the specimen had obvious plastic deformation, the surface roughness of the specimen increased obviously and Ra value increased from 0.47 to 1.33 μm, and the residual compressive stress layer of about 210 μm was formed. The influence mechanism of the residual stress, generated by shot peening, on the fatigue performance of the new TM210A steel was analyzed based on the finite element calculation. The results reveal that the fatigue life and fatigue limit of the new TM210A steel could be significantly enhanced by shot peening, the fatigue limit of the base material specimen was 617 MPa, the fatigue limit of the shot-peened specimen was 847 MPa, and the increase was 37%. The influence mechanism of shot peening on the fatigue performance of the new TM210A steel was that the residual stress generated by shot peening moved the fatigue source from the specimen surface to the interior. It could also be identified that the smaller the external load stress, the deeper the fatigue source is from the specimen surface, the smaller the possible range, and the more obvious the enhancement of fatigue life.