Residual stresses computation in a grinding process

Grinding induces residual stresses, which can play an important role on the fatigue and wear resistance of the component. It is generally expected that conventional grinding leads to tensile residual stresses, while compressive stresses are obtained with high speed grinding (HSG). In this paper, a finite element thermomechanical model for the calculation of residual stresses induced by a surface grinding process on a steel workpiece (AISI 52100) is presented. A model giving the energy conducted as heat in the workpiece as a function of the grinding wheel speed, the workpiece speed, and the cutting depth is proposed. This model is available for conventional grinding for wheel speeds less than 120 m s−1. It is shown that, for such grinding conditions, the simulation leads to tensile residual stresses. Moreover, the computation shows that the temperature in the grinding area increases when the peripheral wheel speed increases too. So it is expected that for wheel speeds corresponding to HSG (>120 m s−1), the surface temperature can reach values leading to an austenitic transformation and therefore, during cooling, the workpiece can be subjected to a superficial quenching leading to compressive residual stresses. Finally, the present paper shows that the metallurgical phenomena in the grinding area must be surrounded and must be taken into account in future models.