Mo-Cr Strengthened Coating Prepared by Plasma Surface Infiltration

Mo-Cr strengthened coating was prepared on the surface of low carbon steel by the double glow plasma metallurgy,ultra-saturated carbonization,quenching,cryogenic treatment and low tempering.The microstructure,composition,microhardness and wear resistance were investigated.The alloyed layer composition was similar to that of molybdenum containing high speed steels.The carbides of the alloyed layer were compact,uniform and dispersed without coarse eutectic Ledeburite structure.The surface hardness after cryogenic treatment for 2 h was up to 1 600 HV,much higher than that without cryogenic treatment.The sliding friction coefficient of different cryogenic treated samples was basically identical.But it reduced about 15% compared with that without cryogenic treatment.Relative wear resistance was more than 1.10 and 2.59 times in comparison with that of Q235 steel carburized and quenched.