Finite-element modeling of the N concentration profile in 31CrMoV9 steel after gas nitriding

This paper presents a possibility for the numerical calculation of the profile of nitrogen (N) concentration in 31CrMoV9 steel after gas nitriding. Samples subjected to gas nitriding at three different temperatures were investigated with different experimental methods. The concentration profile of nitrogen was determined using a Jeol JXA-8900 RL electron probe microanalyzer (Epma). The distance between two points was 5 μm, while the acceleration voltage was 20 kV and the sample current was 40 nA. The nitrogen concentration profile was then modeled using the finite-element method. The program was written in Ansys Parametric Design Language, and the basic element was the three-dimensional element Solid70, while simulation of the model was done in Ansys. Comparison of the results obtained from Epma and modeling confirmed the accuracy of the theoretical approach.