Long-time corrosion resistance of zircon-alumina refractories by molten steel

摘要

Corrosion resistance of alumina-reinforced zircon refractories has been carried out through static crucible test. Corrosion test was carried out by SPK steel for 150 h at the temperature of 1480 degrees C. The corrosion resistance was evaluated by measuring the percentage of the corroded part and the penetration depth of molten steel and observing the microstructure of the refractories. Results showed that the decomposition of zircon sample without any additive has been started at 1650 degrees C and adding 15 wt.% alumina to zircon has led to the accelerating of zircon decomposition. Also, it was concluded that the apparent porosity has approximately a decreasing relation to alumina content as well as temperature. The corrosion resistance of zircon-based composites and the penetration depth of molten steel increased by adding 30 wt.% alumina and decreased with further increase of alumina. Also, the minimum porosity was obtained in the samples containing 15 and 30 wt.% of zircon. Microstructural features of these composites showed zirconia grains embedded in mullite matrix without porosity which may be responsible for providing the corrosion resistance to melt penetration.