Cr-Mo diffusion layer made by double glow plasma surface metallurgy

Cr-Mo diffusion layer on carbon steels was prepared by double glow plasma surface metallurgy and treated by ultra-saturated carbonization, quenching and tempering, the excellent wear resistance was obtained. The results indicated that the hardness of surface alloying was up to 1300 Hv(0.025). The carbides in the alloyed layer were fine and dispersed without coarse eutectic ledeburite. The microstructure of the composite layer indicated that the dimension of surface carbides was less 1 mu m. The abrasion experimental results showed that the average relative wear resistance of modified-steels was 10.3 times as that of T10 steel by quenching and low tempering. The alloy layer possessed a very strong ability resistance to tempering, and its surface hardness exceeds 595 Hv(0.025) after tempering at 690 degrees C for 4h.