Thermodynamics of titanium oxide in ladle slags

It is necessary to have information on the thermodynamic behavior of titanium oxide in ladle type stags in order to control the titanium content in several grades of steel. In the present study, the thermodynamics was determined from the equilibrium between Fe-C-sat-Ti and CaO-SiO2-30%Al2O3-MgO-TiOx stags in equilibrium with CO and from the equilibrium between Fe-C-sat-(16 similar to 18)%Cr-Si-Ti and CaO-SiO2- 20%Al2O3-MgO-TiOx stags in equilibrium with CO. From the experiment with Fe-C-sat-Ti alloy, the activity coefficients of TiO1 5 and TiO2 vary with basicity from 0.3 to 1.5 and from 0.5 to 2.3, respectively. And from the experiment with Fe-C-sat-(16 similar to 18)%Cr-Si-Ti alloy, the activity coefficients of TiO1.5 and TiO2 vary with basicity from 0.4 to 1.4 and from 0.6 to 3.5, respectively. The results obtained from the equilibrium between Fe-C-sat-(16 similar to 18)%Cr-Si-Ti and CaO-SiO2-20%Al2O3-MgO-TiOx stags were used to estimate the titanium content of silicon-added stainless steel. Experiments were also conducted using Fe-Al-Ti melts in equilibrium with CaO-SiO2-Al2O3-TiOx stags saturated with MgO. In this case most of the titanium in the slag is present as TiO2(Ti4+). The present results were used to predict the titanium content of aluminum-killed steel in equilibrium with ladle stags containing titanium oxide and the predictions agreed with plant data.