First-principles simulations of binding energies of alloying elements to the ferrite-austenite interface in iron

The kinetics of the ferrite-austenite (bcc-fcc) phase transformation in steels are markedly affected by substitutional alloying elements. However, the detailed mechanisms of their interaction with the bcc-fcc interfaces are not fully understood. In this study, the effects of common alloying elements (e.g., Nb, Mo, Mn, Si, Cr, and Ni) on the structure, segregation, and magnetic properties of bcc-fcc interfaces in Fe are systematically investigated using spin-polarized Density Functional calculations within a generalized gradient approximation to the exchange correlation potential and a super cell approach with a Kurdjumov-Sachs orientation relationship between bcc and fcc. The calculation results are in semi-quantitative agreement with the experimental results, i.e., Nb has the largest binding energy to the bcc-fcc interface in Fe followed by Mo. Published by AIP Publishing.