Corrosion Behavior of MgO-C Ladle Refractory by Molten Slag

The damage of ladle refractory, which mainly occurs at the position of the slag line, results in an increasing need of maintenance and repair and can, in the worst case, lead to a breakout of melts causing potential risks for the personnel and damage of equipment. On the basis of this fact, the corrosion behavior of MgO–C refractory in contact with molten slag during the steel refining process is experimentally studied in this work. Rotating and static dipping tests of MgO–C refractory in CaO–SiO2–Al2O3–MgO–FeO slags are conducted, and the effects of composition of slag, carbon in refractory, and rotation speed on the corrosion behavior are investigated. Results show that the corrosion depth of the MgO–C refractory increases with FeO content of slag and rotation speed of MgO–C rod, whereas it decreases with an increase in slag basicity. Slag notably penetrates the surface layer of MgO–C refractory after the carbon is oxidized, causing an aggravation of the corrosion. Moreover, the corrosion mechanism of MgO–C refractory in molten slag during the refining process is studied and illustrated in this work.