High temperature mechanical and corrosion resistance of Fe-containing MgO-C refractory in oxidizing atmosphere

Abstract Addition of iron powder is found to be a promising solution to the structure degradation of MgO–C refractory during oxidation, but it may reduce the high temperature properties. To clarify this issue, the influence of Fe addition on the refractoriness under load, creep behavior and slag corrosion resistance in oxidizing atmosphere was investigated. MgO–C refractory exhibited a high maximum working temperature (T0.5, 1720 °C). However, its creep rate at 1550 °C increased rapidly with time because of severe oxidation, causing a failure at an earlier stage. The Fe-containing refractory showed a bit lower refractoriness (T0.5, 1698 °C), while its creep resistance has been greatly improved (1.0% deformation after 50 h duration). The remarkable increase in the bonding degree during oxidation is considered as the main mechanism for the long-term structural stability. Both type of refractories showed good corrosion resistance to oxidized slag due to the presence of graphite and dense MgO layer, but the Fe-containing refractory was more difficult to be penetrated by the slag after graphite oxidation.