Realization of various shot peening intensities and its effect on surface integrity of 18CrNiMo7-6 steel

Abstract As a typical engineering surface strengthening technology, shot peening is believed to allow refining the material grains, increasing the hardness, introducing a residual compressive stress layer, and changing the surface topography. There are many influencing factors of the shot peening technique, which are generally divided into three levels, namely shot peening process parameter, procedure parameter and machine parameter. This study experimentally examined the effect of different shot peening parameters on the peening intensity via type A Almen strip. Then the influence of peening intensity on the surface integrity parameters of carburized steel rollers was explored. Results demonstrate that the intensity is mainly affected by the shot diameter, the air pressure and the shot flow rate. The maximum compressive residual stress reaches −1250 MPa at the intensity of 0.55 mmA. In addition, the surface hardness increases linearly as the intensity increases. The surface roughness parameter Sq can be used to predict the surface hardness after shot peening due to the approximately linear relationship between them.