Anti-wear property of M50 steel by plasma-based ion implantion with nitrogen and carbon

Nitrogen and carbon was implanted into M50 steel by plasma-based ion implantation at elevated temperature with energy of 45 keV. Phase structure of the implanted layer was examined by GXRD. Wear resistance test was performed on a ball-disk wear tester against ZrO₂ ball. SEM and EDS were used to characarize the morphology of the wear track. The results show that the modified layer mainly consists of martensite and small amount Fe₃C and CrN. With the increase of temperature, the compound content increases gradually. Hardness of the modified layers increases obviously. Hardness peak appears for the sample at 300℃, for which the hardness increases by 9.5 GPa than that of the un-treated sample. After the implantation treatment, wear resistance of the M50 steel is improved significantly. Results of SEM show that the dominate wear meachnism of the implanted layer is oxidation wear combined with abrasive wear and adhensive wear.