Abstract:
In this study, nitriding behavior of plasma nitrided X32CrMoV33 die steel was investigated. Nitriding process was carried out at temperatures of 450, 500, and 550 degrees C for treatment time in the range of 2-32h. Depending on nitriding temperature and time, the thickness of compound layer ranged from 2 mu m to 15 mu m. The presence of '-Fe4N, epsilon-Fe2-3N, -Fe, and Cr2N phases formed in the compound layer was confirmed by XRD analysis. Using cross-sectional samples and a microhardness indenter, hardness depth profiles were also obtained; it was found that the hardness of compound layer was over 1000HV. Kinetic studies revealed that the effective diffusion coefficients for plasma nitrided X32CrMoV33 are approximately 40.3x10-14, 99.2x10-14, and 427x10-14m2s-1 for 450, 500, and 550 degrees C process temperatures, respectively. The activation energy for plasma nitrided X32CrMoV33 steel is 118.77kJ mol-1.
