Thermodynamics of titanium and oxygen dissolved in liquid iron equilibrated with titanium oxides

Abstract

The equilibrium relation of Ti and 0 dissolved in liquid iron saturated with solid titanium oxides was measured in the temperature range of 1 823 to 1 923 K. Pure T2O3 (S) phase was identified as the equilibrium deoxidation product for iron melts containing 0.25-4.75 mass% Ti. Using Wagner's formalism, the present results were thermodynamically analyzed to determine the equilibrium constant of T deoxiclation reaction for the formation of pure T2O3 (s) and the first- and second-order interaction parameters between T and 0 given as follows in the temperature range of 1 823 to 1 923 K. [GRAPHICS] The equilibrium titanium oxide phase was identified as Ti3O5(s) for iron melts containing 0.0012-0.25 mass% Ti at 1 873 K. The equilibrium constant of T deoxidation reaction for the formation of pure Ti3O5 (s) were estimated as follows. [GRAPHICS] The activity coefficient of Ti in liquid iron at infinite dilution, gamma(Ti(s))degrees was assessed as 0.011, 0.014 and 0.018 at 1 823 K, 1 873 K and 1 923 K, respectively.