고 Cr 용강 내 Al의 열역학적 거동

Abstract

In the present study, thermodynamic relations among chromium, aluminum and nitrogen in liquid iron were studied using the metal-nitride-gas equilibration technique in the temperature range from 1873 to 1973K. The nitrogen solubility and aluminum nitride formation in liquid Fe-Al and Fe-Cr-Al alloys were measured by the sampling method using a high frequency induction furnace under various nitrogen partial pressures. Using Wagner’s formalism, the first- and the second-order effects of aluminum and chromium contents on nitrogen solubility was determined as a function of temperature. The equilibrium constant for AlN formation in liquid iron was also determined in the temperature range from 1873 to 1973K. The effect of chromium on the solubility product of AlN in liquid iron was measured in order to determine the thermodynamic relation between aluminum and chromium. Using thermodynamic data obtained from Fe-Al-N and Fe-Cr-N systems, the first- and the second-order effects of chromium on activity coefficient of aluminum were determined in liquid Fe-Cr-Al-N alloys containing up to 30 mass%Cr as a function of temperature.