Ultrasonic vibration-assisted grinding processing technology is introduced to solve the problems of low processing efficiency and poor surface integrity of hardened gear steel surfaces in conventional grinding. The comparison experiment of tangential ultrasonic vibration-assisted surface grinding of hardened gear steel AISI 9310 and bearing steel GCr15 were carried out. The ultrasonic vibration-assisted grinding process of gear steel hardened surface is researched through the analysis of grinding force and grinding surface quality. The results show that ultrasonic vibration assisted grinding can effectively reduce the grinding force and specific grinding energy. With the increase of material removal rate

the ultrasonic grinding force ratio is more stable

which is beneficial to improve the grinding efficiency. The experience formulas of the normal grinding force with white alundum grinding wheels in grinding hardened surface of AISI 9310 and GCr15 are obtained

and the relative error is less than 10%. Compared with conventional grinding

the surface roughness of AISI 9310 and GCr15 in ultrasonic vibration-assisted grinding is reduced by 9.47% and 7.39%

when the grinding speed

workpiece infeed speed and grinding depth are 15 m/s

8 m/min and 15 μm

respectively. Under this condition

few defects are observed on the surface machined by the ultrasonic vibration-assisted grinding. This finding indicates that the surface integrity of the workpiece is improved by the ultrasonic vibration.