Thermodynamic Description of Ternary Fe-X-P Systems. Part 3: Fe-Mn-P

Abstract

Thermodynamic descriptions of the Fe-Mn-P system and its binary sub-system, Mn-P, are developed in the frame of a new Fe-X-P (X = Al, Cr, Cu, Mn, Mo, Nb, Ni, Si, Ti) database. The thermodynamic parameters of the binary sub-systems, Fe-Mn and Fe-P, are taken from the latest earlier assessments. Those of the Fe-Mn-P and Mn-P systems are optimized in this study using literature experimental thermodynamic and phase equilibrium data. The solution phases of the system are described with the substitutional solution model and the phosphides are treated as stoichiometric phases or semi-stoichiometric phases of the (A,B) p C q type described with the two-sublattice model. The formation of a miscibility gap in the liquid phase, at high P-contents is predicted.