Predictive Analysis of Austenitization on Grinding Surfaces with a Moving Heat Source Loading Model: Based on Random Grinding Wheel Grit Distribution

Grinding is a critical finishing process for bearing components, yet the highly localized heat generated by high-speed grit–workpiece interactions is difficult to dissipate and can degrade surface integrity. In this study, a grinding wheel is discretized into individual grits and its real topography is characterized by white light interferometry to calibrate the grit distribution. Each active grit is then modeled as a Gaussian point heat source, and a transient finite-element framework is developed to predict the workpiece thermal response under different grinding conditions. The model reveals grit-scale flash heating, with transient peak surface temperatures approaching 800C, while the bulk/macroscopic workpiece temperature remains much lower. The predicted macroscopic temperature evolution agrees well with machine-measured temperature histories, supporting the global heat-input and boundary-condition settings. Compared with a conventional triangular/strip heat-source model, which homogenizes the arc-zone heat flux and underestimates peak surface temperature, the proposed discrete heat-source approach can explain the experimentally observed slight surface austenitization under certain conditions. Overall, the framework provides a mechanistic basis for screening grinding parameters to mitigate thermal damage and improve surface quality.