고 Mn 합금용강 내 AlN 생성거동에 관한 열역학적 연구

Abstract

Thermodynamic relations among manganese, aluminum and nitrogen in liquid iron containing manganese up to 20mass% were studied in the temperature range from 1823 to 1873K. The effect of manganese on the nitrogen solubility in liquid Fe-Mn-N alloys and the solubility product of AlN in liquid Fe-Mn-Al-N alloys were measured by the metal-gas equilibration technique and the metal-nitride-gas equilibration technique, respectively. As the manganese content increases, the nitrogen solubility and the solubility product of AlN increase significantly. Using Wagner’s formalism, the present results were thermodynamically analyzed to determine the first- and second-order interaction parameter between manganese and nitrogen, manganese and aluminum. Therefore, using thermodynamic parameters determined in the present study, the contour lines of critical nitrogen and aluminum contents for the onset of AlN inclusion formation were predicted in liquid high manganese steel melt as functions of melt composition and temperature.