New thermodynamic solution phase data have been optimized for the Fe-S
i-C system to improve the correlation between experiments and calculat
ions obtained in an earlier assessment. New values were optimized for
a binary Fe-Si interaction parameter of liquid phase and ternary Fe-Si
-C interaction parameters of liquid, bcc and fee phases applying exper
imental measurements on mixing enthalpies, solute activities, phase eq
uilibria and solute partition.