Ti-Si 함유 용강 내 질소 용해도 및 TiN생성에 관한 연구

Abstract

Thermodynamic relations among titanium, silicon and nitrogen in liquid iron were studied in the temperature range from 1823 to 1923 K. The effect of titanium and silicon on the nitrogen solubility in liquid Fe-Si-N, Fe-Ti-N and Fe-Si-Ti-N alloys and the solubility product of TiN in liquid Fe-Si-Ti-N alloys were measured by the metal-gas equilibration technique and the metal-nitride-gas equilibration technique, respectively. As the silicon content increases, the nitrogen solubility increase significantly but the solubility products of TiN are constant. Using Wagner’s formalism, the present results were thermodynamically analyzed to determine the first- and second-order interaction parameter among titanium, silicon and nitrogen. Therefore, using thermodynamic parameters determined in the present study, the contour lines of critical nitrogen and titanium contents for the onset of TiN inclusion formation were predicted in liquid Fe-Si steel melt as functions of melt composition and temperature.