Damage mechanism in the use of zirconia sizing nozzle
1. Physical damage a. Thermal shock damage In the actual steel casting process, the zirconia sizing nozzle is heated at a relatively high temperature due to the high temperature of the pouring steel, and the inside of the nozzle is unevenly heated, so that the sizing nozzle is subjected to severe thermal shock. b. Mechanical erosion damage The mechanical flushing of the molten steel to the nozzle is very serious. Although molten steel is a high-viscosity liquid, it has a severe heat wash on the nozzle due to the large ratio of molten steel, high temperature and fast flow rate. 2. Chemical damage a. Zirconia desolvent Zirconium oxide is destabilized due to the desolvation of the stabilizer, and flow away with the molten steel. b. Infiltration and erosion of molten steel and steel slag The molten steel etches the zirconia sizing nozzle to form a low-melting oxide, and the liquid phase formed by the reaction gradually penetrat