Determination of vacancy migration enthalpy in a series of ternary iron-chromium-nickel alloys through Monte Carlo simulations of ordering kinetics using a vacancy diffusion mechanism

We have performed Monte Carlo simulations to calculate Isothermal electrical resistivity curves over time at T’ = 700°K and T’’ = 800°K temperatures. These simulations focused on the kinetics of ordering via a vacancy diffusion mechanism in a series of face-centered cubic (FCC) Fe–Cr-Ni stainless steels (specifically, Fe_75-xCr_xNi₂₅ with x = 8, 10, 13, and 16% Cr, and Fe84-xCr16Nix with x = 25, 45, and 75% Ni). By examining these curves, we were able to calculate the vacancy migration enthalpy in the alloys under study using the technique of slope variation (J. Barkani, Phys. Chem. News. 33:72–79, 2007). For the Fe_75-xCr_xNi₂₅ alloys, the vacancy migration enthalpy decreases as the chromium content increases, ranging from 1.01 eV to 0.97 eV. In contrast, for the Fe_84-xCr₁₆Ni_x alloys, the vacancy migration enthalpy increases from 0.97 eV to 1.27 eV as the nickel content varies from 25 to 45%, and then stabilizes for nickel contents exceeding 45%.