Equilibrium partition coefficients in iron-based alloys

Accurate relationships between equilibrium partition coefficients and solute concentration are required for the prediction of solute redistribution during solidification. Thermodynamic analyses are presented to relate these coefficients to fundamental thermodynamic quantities. Using the most accurate data available, partition coefficients are calculated for ten Fe−X (X=Al, C, Cr, Mn, Ni, N, P, Si, S, Ti) binary systems and compared with literature values. Equations are presented to allow for prediction of these partition coefficients as a function of temperature, as well as liquidus temperature as a function of composition. In addition, partition coefficient values are examined for the ternary systems Fe−Cr−C, Fe−Mn−Ni, and Fe−Ni−S. THOMAS P. BATTLE, formerly Graduate Research Assistant, The University of Michigan This paper is based on a presentation made in the T.B. King Memorial Symposium on “Physical Chemistry in Metals Processing” presented at the Annual Meeting of The Metallurgical Society, Denver, CO, February, 1987, under the auspices of the Physical Chemistry Committee and the PTD/ISS.