Development of interatomic potential for austenitic steel

Itakura, Mitsuhiro  ; Miyashiro, Satoshi*; Okita, Taira*

There are very few studies for the development of interatomic potential for Austenitic steel, owing to the complexity of ternary system of Iron, Chromium and Nickel. In the present study we develop a preliminary version of an embedded atom method type potential for this ternary system. We have carried out first-principles calculations of 50 cases of randomly generated Fe23Cr5Ni4 configurations and observed relaxed crystal structure and total energy. Both the electron density and the crystal structure is found to be very close to that of a perfect FCC lattice system. By a least square fitting, we found that the energy difference between the different configurations is mainly explained by the number of nearest neighbor Cr-Cr and Ni-Ni pairs. The interaction energy between these atoms is on the order of 0.08 eV, and this result endorses the use of randomly generated configurations.