EVALUATION OF COMPONENT ACTIVITIES IN THE MOLTEN C_Fe-X(X=Si,Mn,Cr,Ni)SYSTEM

Expressing the excess partial molar free energies and integral excess free energy as poly-nome of the composition,then the parameters in the expression of excess partial molarfree energy of C were evaluated based on:the excess partial free energy of C in C-Fe bi-nary alloy:the integral excess free energy of Fe-X binary alloy:the C saturation curveand the iso-activity curve of C (α_c=0.025) in the ternary system.Then the activitycoefficient of X was evaluated with the so-called “I-D” method,by which the componentactivities of every element in the whole molten ternary alloy can be evaluated,and theresults are in good agreement with literature data based on experiment.