Thermodynamic assessment of solubility and activity of iron, chromium, and nickel in lead bismuth eutectic

Using the Calphad method and the Thermo-Calc software, a thermodynamic database was developed to assess the interaction between Cr-Ni-Fe alloys and LBE. The current thermodynamic data on the Cr-Fe-Ni + Bi-Pb quinary system was reviewed and the Bi-Cr and Cr-Pb binary phase diagrams were assessed. Fe, Cr and Ni solubilities (in at. fraction, T in K) at LBE composition were calculated:Fe solubility at LBE composition:log10(SFe)=0.5719-4398.6T(399-1173K)Cr solubility at LBE composition:log10(SCr)=-0.2757-3056.1T(399-1173K)Ni solubility at LBE composition:log10(SNi)=2.8717-2932.9T(528-742K)log10(SNi)=0.2871-1006.3T(742-1173K)Then, the thermodynamic assessment performed in this study was used to predict more accurately the Fe, Cr and Ni activities and solubilities in the case of four austenitic model alloys also studied in the framework of corrosion tests [1]. The calculated activities and solubilities provide thermodynamic data to better understand dissolution or precipitation phenomena observed during LBE corrosion processes.