Experimental investigation on the effect of barrel finishing processes on surface integrity of 18CrNiMo7-6 carburized rollers

Abstract

There has been growing interest in enhancing the properties of machine components to improve their reliability in recent years. Surface barrel finishing is one of the most widely used surface processes to decrease the surface roughness of components and improve mechanical properties. However, the effect of barrel finishing parameters on surface integrity such as residual stress and hardness distribution is still unclear, which needs an in-depth understanding. This study experimentally investigated the effect of different barrel finishing media and finishing time on the surface integrity including surface morphology, residual stress, microhardness and microstructure of 18CrNiMo7-6 carburized rollers. Experiment results demonstrate that the surface roughness Sa can be decreased to less than 0.2 μm with the surface barrel finishing, and the surface compressive residual stress (SCRS) can be increased by 500 MPa compared with shot peening process. In addition, the surface microhardness increased by 20 HV and the grain size of the surface layer was refined. The improvement of the surface integrity should be of interest for engineers when designing against rolling contact fatigue.