Thermodynamic Calculations of Phase Equilibria in the Fe–Cr–S System

Abstract

Phase equilibria in the Fe–Cr–S system were analyzed on the basis of the thermodynamic evaluation of the Fe–FeS, Fe–Cr, Cr–CrS and Fe–FeS–CrS–Cr systems. The Gibbs energy of individual phase was approximated by the two sub-lattice model for describing the thermodynamic properties. Most of the experimental information was well described by the present set of thermodynamic parameters. In particular, the calculated liquidus surface in the Fe-rich portion and the solubilities of S in the fcc and the bcc phases were shown to be in excellent agreement with experimental results. Discrepancies observed in some experimental phase diagrams were explained on the basis of the calculated results.