Deoxidation Equilibrium of Niobium in the Iron-Nickel Melts

The oxygen solubility in iron-nickel alloys with niobium was experimentally studied in Fe-40 pct Ni melt at 1823 K (1550 °C). It was shown that the presence of niobium decreases the oxygen solubility in this melt. The equilibrium constant of interaction of niobium with oxygen dissolved in the Fe-40 pct Ni (logK(1)(Fe -40%Ni)=-4.619\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ \log K_{{(1)({\text{Fe - }}40\% {\text{Ni}})}} = {-}4.619 $$\end{document}), the Gibbs energy of this reaction (ΔG(1)(Fe -40%Ni)∘=161,210J/mol\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ \Delta {\text{G}}_{{(1)({\text{Fe - }}40\% {\text{Ni}})}}^{ \circ } = 161 ,210\,{\text{J}}/{\text{mol}} $$\end{document}), and the interaction coefficients characterizing these solutions (eNb(Fe -40pctNi)O=-0.630\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ e_{{{\text{Nb}}({\text{Fe - }}40\,{\text{pctNi}})}}^{\text{O}} = {-}0.630 $$\end{document}; eO(Fe -40pctNi)Nb=-0.105\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ e_{{{\text{O}}({\text{Fe - }}40\,{\text{pctNi}})}}^{\text{Nb}} = {-}0.105 $$\end{document}; eNb(Fe -40pctNi)Nb=0.010\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ e_{{{\text{Nb}}({\text{Fe - }}40\,{\text{pctNi}})}}^{\text{Nb}} = 0.010 $$\end{document}) were determined. In the wide concentration range, the equilibrium constants and Gibbs energy of interaction of niobium and oxygen dissolved in the Fe-Ni melts and the interaction coefficients for these solutions were calculated for 1823 K (1550 °C). For this temperature, the oxygen solubility in the niobium-containing Fe-Ni melts was also determined. With an increase in the nickel concentration in the alloy the niobium affinity to oxygen rises appreciably. This appears to be associated with a decrease in the bond strength between metal and oxygen in the melt as the nickel concentration increases (γO(Fe)∘=0.0084;γO(Ni)∘=0.297\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$ \gamma_{\text{O(Fe)}}^{ \circ } = 0.0084;\;\gamma_{{{\text{O}}({\text{Ni}})}}^{ \circ } = 0.297 $$\end{document}).