Analytical and experimental study on the surface generation mechanism in shot peening

Shot peening is a common surface treatment technology for improving fatigue performance of component and is usually conducted after other manufacturing processes. The surface topography of shot peening directly affects the serve performance and has attracted much interest. To better understand surface generation during shot peening, an analytical model for predicting the peened surface topography was proposed by considering: (i) the random nature of the shot stream, such as the number of shots, spatial distribution, nonuniformity of shot size, and impact velocity; (ii) the overlap of dimples with initial surface and the cyclic hardening. The proposed model is verified by comparing the measured and simulated results. The model can better describe the details of the surface profile compared with the finite element method. It is found that the surface roughness Sa first increases and then decreases slowly with the increase of coverage. Besides, the peened surface of carburized and hardened gear steel shows the combined topography of grinding and shot peening. This work could provide a powerful package to efficiently predict the peened surface topography and guide industrial application in shot peening.