Deterioration mechanism of Al2O3–MgO refractory castable in RH refining ladle

Abstract

The purpose of this work was to investigate the deterioration mechanism of an optimized Al2O3–MgO refractory castable during industrial trials. After structural optimization, the average corrosion rate of every cycle deceased to 0.29 mm/cycle from 0.46 mm/cycle. Corroded microstructure of the optimized Al2O3–MgAl2O4 refractory castable after server 195 cycles was explored. It was indicated that the structural optimization led to an approximate 36% improvement in corrosion resistance than that of comparison one. An adhered slag layer comprising of (Fe, Mg)Al2O4 spinel was observed on the refractory's surface. Iron beans and iron/manganese oxides mainly occurred in the reaction layer, and several penetrating cracks occurred at the corroded interface which would cause potential structural spalling for refractory lining. Based on the observed microstructural characteristics, a corrosion mechanism of refractory lining in a commercial ladle was proposed.

Keywords

• Al2O3–MgO refractory
• RH refining ladle
• Corroded microstructure
• Degeneration mechanism