Microstructure characteristics of steel M50 implanted with nitrogen by plasma-based ion implantation at elevated temperature

Steel M50 was modified by plasma-based ion implantation (PBII) at different temperatures. The results of scanning electron microscope (SEM) indicate that PBII at elevated temperature can reduce both grain size of substrate and precipitates in the implanted layer and remove the network microstructure of carbides in the substrate. Glancing angle X-ray diffraction (GXRD) analysis indicates that the elevated temperature is in favor of the formation of nitrides. The diffraction peaks of nitrides are obvious when the temperature is higher than 300 oC with implantation voltage of 25 kV