Investigation on Surface Characteristic and Tribological Behavior of BS960 Steel by Using Micro-shot Peening and Traditional Shot Peening

Shot peening is an important surface hardening method to strengthen the wear resistance of treated components, and the enhancement efficiency is largely determined by the surface characteristic after the treatment. Here, BS960 high-strength steel was treated by traditional shot peening and micro-shot peening, respectively. The surface characteristic such as residual stress, roughness, and hardness was characterized, and the wear test was performed to evaluate the tribological behavior after the treatments. The results showed that after traditional shot peening and micro-shot peening, the micro-hardness was increased from 389 HV_0.3 of untreated sample to 494 and 506 HV_0.3, and compressive residual stress was reached up to −404 and −506 MPa, respectively. Compared with the traditional shot peening treatment, the residual stress distribution was more uniform on the surface after micro-shot peening. The wear test results showed that the friction coefficient was decreased from 0.61 of untreated sample to 0.46 of samples after micro-shot peening, and the wear volume was also decreased effectively. The enhanced surface hardness and compressive residual stress were responsible for it.