Simulation of the Growth Kinetics of FeB and Fe2B Layers on AISI D2 Steel by the Integral Method

In the present study, a new diffusion model based on the integral method was suggested to investigate the boriding kinetics of pack-borided AISI D2 steel. This diffusion model considered the effect of boride incubation time of the total boride layer (FeB + Fe2B). Firstly, the diffusion coefficients of boron in the FeB and Fe2B layers were estimated using a simple approach derived from the integral method. Secondly, the values of boron activation energies for the FeB and Fe2B layers were determined and compared with the literature data. The formulated diffusion model has been validated by using additional boriding conditions. The total boride layer thicknesses, obtained experimentally at 1243 K for 2, 4 and 6 h, were compared to the predicted thicknesses. Finally, a good agreement was observed between the experimental and the predicted results.