Solubility of Titanium and Carbon in Molten Fe-Ti Alloys Saturated with Carbon

The solubilities of titanium and carbon in Fe-Csat Ti alloys were determined at temperatures from 1300°C to 1500°C. Some of the already reported values of titanium solubility were determined by measuring the acid-soluble titanium dissolved in rapidly cooled samples which inevitably contain the particles of titanium carbide sedimented during cooling. The sedimentation of titanium carbide results in the difficulty in determining the accurate solubility of titanium. In order to solve this difficulty, methods were newly devised to measure the total titanium content in rapidly cooled samples.The results obtained are as follows;(1) The solubility of titanium at temperatures from 1300°C to 1500°C was expressed as, log[%Ti]=(-6760/T)+3.965(2) By the use of the carbon solubility in iron with different concentrations of titanium, the temperature dependence of the interaction coefficient, eCTi, at temperatures from 1350°C to 1500°C was determined as, eCTi=(-221/T)-0.072(3) The change of standard Gibbs free energy for the reaction, Ti+Csat=TiC(s), was obtained as ΔG°=-30500+13.3T (cal/mol).