Relationship Between Activity Interaction Parameters in Fe-C System and Temperature Original Research Article

Carbon solubility in Fe-Mn melts (xFe = 0.102 3 − 0.789 9, xMn = 0.055 1 − 0.638 0) was measured experimentally at various temperatures. Using Gibbs-Duhem equation, in combination with the experimental results in this work, quoting experimental data reported in references, and by strict thermodynamic derivation and calculation, the relation equations between the activity interaction parameters in Fe-C system and temperature were obtained. The calculation equation of lnγFe in Fe-C system was also obtained. The calculated results show that these relation equations can be used to calculate the activity coefficients of carbon and iron in Fe-C system and can satisfy the necessary condition to satisfy Gibbs-Duhem equation and the necessary condition to satisfy the stability condition of system at high carbon content. The calculation formula for ln/c in Fe-Mn-C system was also obtained.