Thermodynamic Interaction between Chromium and Aluminum in Liquid Fe–Cr Alloys Containing 26 mass% Cr

Abstract

Thermodynamic interaction of chromium on aluminum in liquid Fe–Cr–Al alloys was studied by measuring the effect of chromium on the solubility product of AlN in liquid Fe–Cr–Al–N alloys containing chromium up to 26 mass% by the metal–nitride–gas equilibration technique in the temperature range from 1873 to 1973 K. Aluminum nitride formed in the melt was identified as a pure solid stoichiometric AlN. As the chromium content increases in the melt saturated with AlN, the critical nitrogen solubility increases significantly, while the aluminum solubility decreases. Using Wagner's formalism, the present results were thermodynamically analyzed to determine the first- and the second-order interaction parameters between chromium and aluminum given as follows:eAlCr = 0.0122±0.00028 rAlCr = 0 (1873−1973 K, Cr≤26 mass%)