Thermodynamic Relation between Silicon and Aluminum in Liquid Iron

Abstract

The thermodynamic relation between silicon and aluminum in liquid iron was studied by measuring the effect of silicon on the solubility product of AlN in liquid Fe-Si-Al-N alloys containing silicon up to 1.5 mass pct in the temperature range from 1823 K to 1923 K (1550 °C to 1650 °C). The effects of aluminum and silicon on nitrogen solubility in liquid iron were separately determined in the same temperature range. The experimental results were thermodynamically analyzed using Wagner’s interaction parameter formalism to determine the first-order interaction parameters of silicon on nitrogen and aluminum in liquid iron as follows: \( e_{\text{N}}^{\text{Si}} = 0. 0 6 7 3, \;e_{\text{Al}}^{\text{Si}} = 0.009 \) (1823 K to 1923 K (1550 °C to 1650 °C), Si ≤ 1.5 mass pct)