A Cellular Automata Model for Nitriding of Nanocrystalline Iron

In this study, a numerical model was developed to investigate the effects of grain refinement on the efficiency of nitrogen diffusion during the nitriding process. A cellular automata (CA) model without considering the effects of grain boundaries was built to simulate the nitriding process. The results from the numerical model were compared and validated by experimental data in the literature. Then, nanoscale grain boundaries were integrated into this CA model. The nitriding efficiency in materials with different grain sizes was investigated. The results demonstrate that nanocrystallization can significantly increase the nitrogen diffusion efficiency and thus make low temperature (300°C) nitriding possible.