The main function of the tundish is to receive the molten steel poured from the tundish. When the liquid level and temperature of the molten steel meet the requirements, the plug rod is raised to pour the molten steel into the steel ingot mold. During the casting process, the tundish has the functions of stabilizing the liquid level, reducing the hydrostatic pressure of the molten steel, promoting the floating of inclusions in the molten steel, purifying the molten steel, and controlling the temperature of the molten steel poured into the ingot mold. The refractory materials of tundish mainly include working layers, plugs and spouts.
Title：Refractory materials for tundish for steelmaking
Keyword：Steelmaking / tundish / refractory material / working layer / plug rod / nozzle
From the analysis of the use environment of the tundish, the refractory materials used need to meet the following conditions: ① Good thermal shock resistance, no cracking when the steel is hot and cold before and after pouring; ② Low heat conductivity and thermal expansion, so that the tundish has good thermal insulation properties;Resistant to molten steel erosion, small pollution to molten steel during the casting process; Easy to clean up, easy to turnover and use.
Due to the high SiO2 content of laparite material, which reaches more than 65%, under the action of high temperature and slag, a high-viscosity liquid phase will be produced on the surface, forming an isolation layer to prevent the liquid steel and slag from continuing to penetrate, thereby reducing the melting and erosion rate of the material. After zirconia is added to the refractory material, it can significantly improve the thermal and chemical stability of the material, and delay the erosion of the refractory material by molten steel. Moreover, zirconia is easy for refractory materials to form a high melting point composite, which makes it difficult for refractory materials to enter molten steel and improves the purity of molten steel. Due to the comprehensive consideration of cost and product quality, the tundish working layer can be made of quartz refractory material and zirconium mullite material according to the products produced, the plug rod is made of aluminum-carbon material, and the nozzle is made of zirconium and aluminum-carbon depending on the product requirements.