Thermodynamic assessment of the Mn–S and Fe–Mn–S systems

The Fe–Mn–S system is of great importance for the steelmaking process. As part of the work for the development of a large self-consistent thermodynamic database for such applications, the aim of the present assessment was to obtain a thermodynamic description of the Fe–Mn–S system using the ionic two-sublattice model for the liquid. Previous compatible descriptions of all unaries as well as two of the constituent binaries, Fe–Mn and Fe–S, were accepted. The third binary, Mn–S, was assessed in this work. Ternary parameters were optimised for the liquid, the alabandite, the pyrrhotite and the pyrite phases. Calculations using the present description agree well with experimental data.