Simulation of Boriding Kinetics of AISI D2 Steel using Two Different Approaches

Diffusion of boron in FeB and Fe2B layers under solid boriding of steel AISI D2 (the Russian counterpart is Kh12MF) is simulated. Two approaches are used to assess the diffusion coefficients in solid-phase boriding, i.e., the concept of the mean value of diffusion coefficient in the FeB - Fe2B system and consideration of the growth kinetics of each of the two boride layers with the use of a system of conventional differential equations describing the partial chemical reactions by a parabolic law (the Dybkov method). The activation energies of boron diffusion in the FeB and Fe2B layers of steel AISI D2 are computed. The condition of extreme boriding is used to verify the two approaches experimentally. Comparative analysis of the computed and published data shows their good agreement.