Thermodynamic reassessment of Fe-Cr-Ni system with emphasis on the iron-rich corner

Thermodynamic reoptimization has been made for the Fe-Cr-Ni system with emphasis on the iron-rich corner of the system. New ternary substitutional-solution interaction parameters were optimized for the liquid, fcc and bcc phases and a new Gibbs energy expression was suggested for one hypothetical component of the sigma phase. The rest of the data concerning the binary subsystems and the sigma phase were taken from earlier assessed Fe-Cr-Ni descriptions. The calculated results were validated with numerous experiments of phase equilibria, solute partition and component activity. The results were also compared with those of two earlier Fe-Cr-Ni assessments showing improved or equal agreement with most experiments. Only for the liquidus temperatures at high chromium and nickel contents (above 30wt%) is the agreement worse than in the earlier assessments.