Composite submerged entry nozzle inner lining material used for continuous casting

Abstract

The invention discloses a composite submerged entry nozzle inner lining material used for continuous casting, and belongs to the field of functional flame-retardant materials used in steel metallurgyindustry continuous casting. The composite submerged entry nozzle inner lining material is composed of, by weight, 65 to 80 parts of barium zirconate, 10 to 20 parts of fused silica, 5 to 10 parts ofmullite, 3 to 5 parts of boron nitride, and 6 to 8 parts of phenolic resin. In applications of the composite-structure submerged entry nozzle inner lining material, introducing of molten steel into acrystallizer through a tundish is adopted, utilization of the characteristics that low melting point compounds are easily formed from aluminium oxide and barium oxide, a layer of liquid phase is formed on the submerged entry nozzle internal wall, aluminium oxide adhesion is prevented, and blocking is prevented.

Description

technical field [0001] The invention discloses a composite submerged nozzle lining material for continuous casting, which belongs to the field of functional refractories for continuous casting in the iron and steel metallurgy industry. Background technique [0002] The submerged nozzle is installed in the tundish, which is the passage for the molten steel from the tundish to the crystallizer, and has the functions of preventing the secondary oxidation of the molten steel and distributing the flow. It is the most important functional refractory material for continuous casting of iron and steel. Its quality will directly affect whether the entire continuous casting process can be carried out normally. billet quality. [0003] The submerged nozzle is generally made of aluminum carbon material. When the molten steel passes through, the surface is decarburized, forming a rough porosity structure, and the molten steel invades into the pores, and local stagnation of the molten ste...

AI Technical Summary

Problems solved by technology

As the pouring proceeds, the deposit layer thickens, the pore size shrinks, and finally blocks until the pouring stops, which brings unnecessary losses to the steel plant; at the same time, inclusions are easy to enter the molten steel from the submerged paddy field again during the casting process, forming Large inclusions reduce billet quality

[0004] In order to solve the problem of submerged nozzle blockage, many methods have been adopted, such as argon blowing, structural anti-blocking, etc., as well as material anti-blocking, and a layer of material Zr0 is compounded on the inner wall of the submerged nozzle. 2 -CaO-C, MA, MA-boron nitride anti-clogging material, Chinese patent 200410053219.4 announced a kind of anti-clogging material mainly composed of zirconium mullite and ß-sialon, Chinese patent 201010236300.1 announced a kind of anti-clogging material based on titanic acid Aluminum is the main raw material. Chinese patent 201410479543.6 discloses a material containing wollastonite and calcium titanate, etc., but these materials are highly targeted, and can effectively prevent the submerged nozzle from clogging only when using a specific steel type

When casting special steel such as bearing steel, there are many aluminum oxide inclusions in the molten steel, and the submerged nozzle is easy to block. The above-mentioned materials will not be effective because of the low temperature of the molten steel and strong adhesion.