In view of the performance change of strengthening layer of gear steel 30CrMnTi material under dry grinding condition, through grinding test, firstly analyze the microstructure change of strengthening layer after grinding, then carry out grinding strengthening test with different grinding speed and grinding depth, and study the change law of microhardness gradient, depth of strengthening layer and microhardness of grinding surface. The results show that:
(1) After grinding, the surface microstructure of gear steel 30CrMnTi is acicular martensite + carbide + a small amount of residual austenite, and the core microstructure is plate martensite + ferrite. The martensite structure of strengthening layer is relatively uniform, and the change trend of “fine coarse” from grinding surface to core.
(2) After grinding, there is a certain degree of strengthening layer on the surface of 30CrMnTi. The hardness increases first and then decreases with the increase of surface depth. The depth of strengthening layer increases with the increase of grinding depth or grinding speed.
(3) The surface microhardness of 30CrMnTi after grinding is higher than that before grinding, and the hardening degree is between 2% and 13%. The surface microhardness increases with the decrease of grinding speed or the increase of grinding depth.