Impact of dry grinding and wet grinding on surface layer strengthening of 42CrMo steel

Grind-hardening test under different cooling conditions(dry grinding,wet grinding) for 42CrMo steel was carried out on precision horizontal grinding machine M7132A.The studies show that the microstructure of fully strengthened layer is hybrid martensite,which is dominated by lath martensite.Microhardness of strengthened layer is above 700HV and increases three time than that of matrix.Under the same grinding technology,the thickness of grind-hardening strengthened layer under wet grinding is maximum.