Effect of Al2O3 Refractories on Oxygen Content of Molten Fe–Cr Alloy

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. The case of using alumina refractories is considered in the present work. Molten Fe–Cr alloy equilibrated with Cr2O3–Al2O3 solid solution when Cr content of the alloy was high and equilibrated with FetO·(Cr, Al)2O3 solid solution when Cr content of the alloy was low. The equilibrium oxygen contents in Fe–Cr alloy at given Cr contents using Al2O3 crucible in the present work were lower than those using Cr2O3 crucible reported previously. It was found that oxide in equilibrium with Fe–Cr alloy will control and affect the O content when Al content is low.