Activity measurement of FeOCr2O3 in " FeO(Cr, Al)1O3" solid solution

Abstract

Thermodynamic information on the equilibrium between dissolved Cr and O in steel melt is the basic knowledge to control Cr content in the stainless steel production process. In the case of using alumina refractories, molten Fe-Cr alloy equilibrates locally with 'FeO(Cr, Al)2O3' solid solution at the interface between the melt and refractories when Cr content in the alloy is low. Wide composition range of 'FeO(Cr, Al)2O 3' solid solution is known, and the activity data of FeOCr 2O3 in 'FeO(Cr, Al)2O3' solid solution is required to precisely estimate and control the Cr-O equilibrium relation in molten Fe-Cr when the alloy is produced in the furnace lining by Al2O3 refractories. In the present work, crucibles made of 'FeO(Cr, Al)2O3' solid solution were equilibrated with molten Ag under CO-CO2 gas mixture at 1 873 K to determine the activity of FeOCr2O3 in the solid solution. © 2013 ISIJ.