Numerical simulation of nitrided layer growth and nitrogen distribution in epsilon-Fe2-3N, gamma '-Fe4N and alpha-Fe during pulse plasma nitriding of pure iron

摘要

The surface phase constitution and the kinetics of layer growth in pure iron pulse plasma nitrided at 520 degrees C for different times were systematically studied, and the relative expressions of the nitrogen concentration profiles in nitrided layers have been deduced. The results show that the nitrided layer consists of epsilon-Fe2-3N (epsilon), gamma'-Fe4N (gamma') and alpha-Fe (alpha) phases, and its growth in thickness follows a parabolic law. In addition, the growth of a compound layer and diffusion layer and the nitrogen concentration distribution in the nitrided layers can be precisely predicted by employing the mathematical models obtained. [References: 8]