The material and structure of the submerged entry nozzle have a great influence on the flow of molten steel in the mold and tundish, which is directly related to the quality of steel products. Different smelting methods have different submerged entry nozzle materials. Currently, the main nozzle materials include fused quartz, aluminum zirconium carbon, aluminum carbon, etc. Depending on the type of casting billet, the structure of the submerged entry nozzle used is also different. The straight-cylindrical submerged entry nozzle is mainly used for pouring billets, rectangular billets or small slabs, and the double-side hole type submerged entry nozzle is mainly used for pouring blooms. , slab, while the upward side hole type immersion nozzle is mainly used in the stainless steel pouring process.