Experimental Study on Surface and Subsurface Defect Characteristics of 8Cr4Mo4V Bearing Steel After Grinding

Due to its excellent high-temperature resistance and fatigue properties, 8Cr4Mo4V high-temperature bearing steel has become a critical material for aero-engine main shaft bearings. Consequently, the surface integrity of this material after grinding directly determines the service performance and fatigue life of the bearings. To address the lack of clarity regarding the correlation between grinding process parameters and defect characteristics under strong thermal–mechanical coupling, systematic grinding experiments were conducted in this study. Scanning Electron Microscopy (SEM) and white light interferometry were employed to observe the ground surface morphology and subsurface damage characteristics under various process parameters. On this basis, the influence of key parameters—such as wheel linear speed and grinding depth—on the formation and distribution of defects, including micro-cracks and material spalling, was analyzed in depth. Through qualitative and quantitative analyses, this study aims to elucidate the mechanisms by which grinding parameters affect machining defects, thereby providing experimental data and references for the optimization of the grinding process for this type of material.