The submerged nozzle is a key functional refractory component in the continuous casting process. It is installed at the bottom of the tundish, and the lower end is immersed in the protective slag layer in the crystallizer, deep below the steel liquid surface. It undertakes the core functions of precise molten steel flow guidance and casting flow shape control, and plays a decisive role in the stability of continuous casting and the quality of the ingot.
Prevent secondary oxidation of molten steel, control the flow state and injection speed of molten steel, promote the floating of inclusions, and prevent non-metallic inclusions such as protective slag from being drawn into the molten steel.
It must have good resistance to molten steel erosion, slag erosion and thermal shock. Commonly used materials include fused quartz and Al₂O₃-C.
There are side holes, straight-through type, hemispherical, special-shaped thin-walled and other forms. Its structure must meet the requirements of smooth injection movement, reduced impact depth, high temperature, and prevention of air entry.
