Thermodynamic calculation of the stacking fault energy in Fe-Cr-Mn-C-N steels

To determine the thermodynamic parameters for the calculation of the accurate stacking fault energy (SFE) in Fe-Cr-Mn-C-N steels using the sublattice model, the comparison between the calculated and experimental SFE values was conducted. It was realized that the relationship between SFE and alloying elements in Fe-Cr-Mn-C-N steels was different from that of the conventional Fe-Cr-Ni stainless steels. The SFE increased with the increasing Cr concentration up to a critical value, then decreased again with further increased Cr concentration. The critical value decreased with the addition of Mn, C and N. In contrast to Cr, the addition of Mn continuously increased the SFE, regardless of the additions of C and N. Regarding the C and N, they also increased the SFE linearly and the impact of N on the SFE was only slightly effective relative to that of C. Accordingly, we realized that the thermodynamic calculation using the suggested combination of thermodynamic parameters should be considered for more accurate SFE calculation in Fe-Cr-Mn-C-N steels. (C) 2018 Elsevier B.V. All rights reserved.