A thermodynamic model for non-stoichiometric cementite; the Fe-C phase diagram

On the basis of recently published experimental data a new thermodynamic model for the cementite phase was developed, accounting for its non-stoichiometry in equilibrium with alpha, gamma and liquid solution phases. The predictions from the model were discussed in the context of experimental and ab initio data from the literature. Further, the model was compared to existing models for stoichiometric and nonstoichiometric cementite. It was shown that the resulting description is consistent with thermodynamic descriptions of the Fe-C system, excluding the non-stoichiometry of cementite, from the literature. Thus, the new model is suitable as a basis for multi-component systems correctly predicting the constitution of technically applied alloys. (C) 2015 Elsevier Ltd. All rights reserved.