Sizing Nozzle Introduction:
According to the structure, the sizing nozzle can be divided into three categories: homogeneous sizing nozzle, direct composite sizing nozzle and inlaid sizing nozzle.
According to the particle size of raw materials used in the production of sizing nozzles, it can be divided into three types: coarse particle type, fine particle type and pottery type sizing nozzle.
Zirconia nozzle is one of the tundish refractory materials in continuous casting process. It is mainly used in billet continuous casting and can control the flow of molten steel. Zirconium sizing nozzle, the inner core uses zirconia as the main raw material, is widely used in billet continuous casting tundish. Zirconium sizing nozzle is mainly used for continuous casting of tundish billets, blooms, rectangular billets, and small slabs for pouring steel.
Zirconium Sizing Nozzle Advantages:
reasonable structure ,strong errosion resistance and stable speed in the casing process.
Zirconium Sizing Nozzle Application:
The company developed zirconium sizing nozzle,which is specially used in small billet caster tundish without plug stem gating system,and it is more suitable for small billet cc.
The advantages of the tundish sizing nozzle rapid replacement system include:
1. The application of rapid replacement of sizing nozzle technology can avoid excessive drawing speed and steel leakage caused by excessive nozzle erosion.
2. Increase the number of continuous casting furnaces in single ladle, reduce the surplus steel in tundish, improve the billet yield and billet quality, and achieve the purpose of reducing cost and increasing benefit.
3. It can quickly stop pouring, restart pouring and replace sizing nozzles with different apertures during casting, so as to adapt to the best matching of molten steel temperature, fluidity and drawing speed in the later stage of casting and the molten steel supply in front of the furnace, so as to promote the balance and stability of production organization.
4. Improve the service life of tundish and reduce the consumption of tundish lining refractory, baking energy and laying manpower.
The development of Zirconia nozzle
Zirconia nozzle is mainly made of zirconium oxide as raw material, fired at high temperature by advanced technology, and has good erosion resistance and erosion resistance; good thermal shock stability, no bursting when used; longer The service life is up to 20h. The zirconium sizing nozzle is one of the refractory materials for billet continuous casting, which plays a role in controlling the flow of molten steel. The molten steel flows through the sizing nozzle evenly and steadily into the crystallizer, which is a necessary condition to ensure continuous casting. Therefore, the zirconium sizing nozzle should have good corrosion resistance and thermal stability, and it is not allowed to block, fall off, crack and expand diameter during use.
The expansion of zirconia nozzle will lead to too much molten steel flowing into the product. The casting machine is forced to increase the pulling speed and cause a steel leakage accident. The casting machine is often stopped due to the expansion of the sizing nozzle, bursting or falling off. In the early stage of continuous casting development, the continuous casting time is short, and the common zirconium sizing nozzle made of zirconia and zirconia can meet the requirements. The zirconia content is 72%-85%. When the continuous casting time is greater than 500min, the zirconite reacts with some components in the molten steel and decomposes, resulting in the expansion of the sizing nozzle. The ordinary zirconium sizing nozzle can no longer meet the use requirements. A sizing nozzle made of zirconia with better erosion resistance must be used. The content of zirconia is 93%-95%. The zirconia sizing nozzle is resistant to erosion and has good thermal stability. It can realize multi-furnace continuous casting, improve the efficiency of the casting machine, and reduce the production cost.