Research on the Mechanism of Residual Stress and Its Influence on Fatigue Life in Grinding Superalloy

Abstract

This research is focused on the formation mechanism of residual stress and effect of various process parameters, thermal coupling levels and grinding ways on residual stress during grinding superalloy, as well as analyzed the relationship between residual stress and fatigue life. The results show that the residual stress for grinding process is caused by the interaction between grinding temperature and grinding force, and in general the thermoplastic deformation and the plastic pressure coarse effect generated tensile residual stress because of grinding temperature and abrasive mechanical action, respectively, while the burnishing effect generated the compressive residual stress. From the experimental results, it is observed that using plunge-cut grinding process resulted in tensile residual stress on machined surface and the tensile residual stress increases with increasing grinding depth and wheel speed, while the maximum tensile residual stress occurred near the grinding surface, and then declined sharply. The residual stress layer is approximately 100μm while the depth of residual stress layer and the maximum tensile residual stress are increased with increases the grinding parameters. Meanwhile, the studies also indicate that the fatigue life improves with increase in compressive residual stress, whereas the tensile residual stress has the opposite effect on fatigue life. Thus, this paper provides the related experimental data for the study of anti-fatigue manufacturing in grinding superalloy.