Study on the heterogeneous layer of H13 steel induced by ultrasonic surface rolling and the enhancement effect on its wear resistance

This exploratory study focuses on the effects of Ultrasonic Surface Rolling Peening (USRP) on the heterogeneous layer of H13 steel and its enhancement of wear resistance. USRP treatment introduces a complex heterogeneous layer on the H13 steel surface, comprising a gradient residual stress field and a high-density dislocation array. Following USRP treatment, the surface residual compressive stress is significantly increased to -933 MPa, and the dislocation density is elevated to 5.092×10 15 m -2 , which is 4.29 times that of the untreated specimen. In terms of wear resistance, the wear volume of USRP-treated H13 steel is reduced by 32.39%, 44.27%, and 50.79% after 40 minutes, 5 hours, and 10 hours of wear testing, respectively. The wear mechanism shifts from severe abrasive and adhesive wear to slight adhesive wear. The reduction in wear volume increases with wear time, and the rate of wear volume increase is significantly lower compared to untreated specimens. The results demonstrate that USRP treatment effectively enhances the wear resistance of H13 steel, with the sub-surface layer exhibiting the most pronounced improvement. The surface heterogeneous layer, synergistically constructed by the gradient residual stress field and high dislocation density, plays a crucial role in improving wear resistance.