Abstract
The phase diagrams of Fe-C, Co-C and Ni-C systems have been studied by computer calculations combined with thermodynamic analysis. The Gibbs energy of the individual phase was described by the regular solution-sublattice model, and the empirical parameters were determined from selected data on the activity of carbon as well as the phase boundary composition. A special care has been taken to account for the effect of magnetic transition in bcc Fe, fcc Co and Ni. The calculated phase diagrams differ only slightly from others previously published, but this revision will permit the calculation of phase equilibria for multi-component ferrous alloys with greater accuracy.
