Research status of the influence of machining processes and surface modification technology on the surface integrity of bearing steel materials

The surface integrity of bearing steel materials largely determines the life of mechanical parts like bearings and gears. Optimizing the process parameters or applying surface modification technology can improve the surface integrity of materials. In this paper, the definitions and characteristics of the evaluation parameters of surface integrity and their influences on mechanical part performance were reviewed. The influences of machining processes (forging, cold rolling, heat treatment, turning, grinding, and super-finishing) for bearing steel materials on parameters related to surface integrity including metal streamline distribution, surface roughness, surface waviness, surface defects, micro-structure, residual stress, and micro-hardness were summarized. Several typical surface modification technologies applied to bearing steel materials were summarized, including surface coating technology, chemical heat treatment technology, ion implantation technology, reinforced grinding technology, shot peening technology, and composite modification technology. Finally, two new surface modification technologies which can be applied to bearing steel materials in the future were introduced (ultrasonic surface rolling process and laser shock peening). It can provide certain research directions and theoretical references for improving the surface integrity of bearing steel material in this paper.