Influence of Original Structure on the Grind-Hardened Layer Structure and its Property of 65Mn Steel

On the basis of the surface grind-hardening experiment, the influence of original structure on the grind-hardened layer structure and its property of 65Mn steel were studied using optical microscope, scanning electron microscope, and digital microhardness tester in detail. The results show that under the comprehensive function of the temperature field and the stress-strain field, original structures have little remarkable effect upon the microstructure of grind-hardened layer and its high microhardness value. The hardened layer comprises entirely hardened zone and transitional zone, and the entirely hardened zone whose microhardness ranges from 810HV0.5 to 870HV0.5. Additionally the depth of grind-hardened layer and entirely hardened zone vary with different original structures, and the higher depth of it can be obtained when material initially quenched and tempered is selected.