Determination of Aluminum and Oxygen Contents in Liquid Iron in Equilibrium with α-Alumina and Hercynite
The constitution of <u>Al</u> and <u>O</u> at 1873 K at the coexisting point, at which the Fe-Al-O system was in equilibrium with both of FeO·Al<sub>2</sub>O<sub>3</sub> and α-Al<sub>2</sub>O<sub>3</sub>, was investigated, and the measured <u>Al</u> and <u>O</u> contents were found to be 0.072 mass% <u>O</u> and 0.0018 mass% <u>Al</u>. The <u>O</u> content of this point agrees well with other measured values. The <u>Al</u> content of this point is two orders of magnitude larger than the activity of <u>Al</u> but agrees fairly well with the <u>Al</u> content predicted by an associated solution model and that measured by Novokhatskiy <I>et al.</I> This result reveals that the equilibrium curve (E.C.), which indicates the <u>Al</u> and <u>O</u> contents in liquid Fe in equilibrium with α-Al<sub>2</sub>O<sub>3</sub>, is a concave curve in the low <u>Al</u> region that extends to the coexisting point. However, the E.C. calculated using the interaction parameters and deoxidation constant <I>K</I> is almost a straight line. This discrepancy indicates that the use of the interaction parameters reported for this system is probably inappropriate in the concave E.C. region. The interaction parameters and thermodynamics of this system should be reexamined.
- ISIJ international
ISIJ international 39(8), 760-766, 1999-08-15
The Iron and Steel Institute of Japan