Effect of grinding speed on grinding hardened layer of 42CrMo steel

Grinding hardening tests were carried out on 42CrMo steel with precision horizontal grinding machine M7132A,and the effects of grinding speed on microstructure and hardness of the strengthened layer were investigated.The results show that the microhardness value of completely strengthened layer can reach 724-824 HV0.1 which raises 3 to 4 times compared with the matrix,and the microhardness value of workpiece's surface increases with increasing grinding speed.Microstructure of the completely strengthened layer is mixed martensite,mainly with lamellar martensite.With increasing grinding speed,the microstructure of strengthened layer is refined and the depth of completely strengthened layer increases too.