Numerical analysis on Si deoxidation of molten Fe-Ni and Ni-Co alloys by quadratic formalism

Relation between the activity coefficient expressed by Darken's quadratic formalism and the excess Gibbs energy change of mixing described with Redlich-Kister type polynomial was discussed on Si deoxidation of Fe-Ni and Ni-Co alloys. The activity coefficients of Si and O in metal expressed by quadratic formalism have been converted into formula using interaction parameters Omega(i-j) under the condition where concentration of Si and O are dilute. Numerical analysis on Si deoxidation of molten Fe-Ni and Ni-Co alloy has been carried out. It has been found to be outstanding in the agreement of equilibrium Si and O contents in molten Fe-Ni and Ni-Co alloy analyzed in the present work with the experimental results. The deoxidation equilibrium of not only one component metal but also alloy can be analyzed numerically using the formula determined in the present work.