Submerged Entry nozzles and long nozzles have a great impact on process quality and process efficiency during steel continuous casting, so choosing a scientific and reasonable nozzle in structure and material is of great significance.
1.submerged Entry nozzle
In the continuous casting operation, one end of the submerged nozzle is connected to the tundish, and the other end is connected to the mold. There is a submerged nozzle between the tundish and the mold. On the one hand, its main function is reflected in the injection of molten steel into the copper mould tube, and on the other hand, it is reflected in the prevention of oxidation in the steel industry. Therefore, it’s used as a functional refractory part, it must have good penetration performance and sealing performance. Therefore, considering the design and material selection of the submerged nozzle, the state of the steel flow, the surface shape of the billet and its solidification state must be fully considered.
1.1Shape of submerged Entry Nozzle
According to the different installation methods of the submerged nozzle, there are two different modes, one is the built-in submerged nozzle, and the other is the external submerged nozzle. However, the design or selection of the nozzle shape we are talking about mainly refers to the angle and shape of the steel outlet. The reason why we need to carry out a reasonable design for the shape of the nozzle is to better make the sundries in the crystallizer float up and then take them out. However, in the actual pouring operation, different steel types, different pouring speeds, and different crystallizer cross-sectional sizes will have different requirements in the pouring operation. Therefore, when we consider which shape of the submerged nozzle should be used, it is It is considered based on enabling the steel flow to have a strong flushing effect on the front of the solidified shell.
2.Long Nozzle
In the continuous casting operation, the long nozzle is located at the lower nozzle of the sliding nozzle of the ladle, and its main function is to prevent the molten steel from being oxidized due to contact with the atmosphere when it flows to the tundish. For continuous casting operations, the long nozzle is of great significance, not only related to its steel forming efficiency, but also related to the yield. Therefore, for the shape of the shroud, the choice of material is also of great significance. Compared with submerged nozzles, long nozzles also need to have many advantages such as crack resistance and corrosion resistance.
Compared with submerged nozzles, long nozzles have a higher probability of cracking or breakage during use, so in the process of material selection, more attention should be paid to its crack resistance. Because in terms of appearance, the shroud is larger and heavier, so it will receive much greater mechanical impact no matter in the process of installation or use. Moreover, compared with the submerged nozzle, the long nozzle does not have a special preheating device, so it needs to withstand more severe heat during use.
