A nozzle that can prevent the pipe and the bottom of the discharge hole from sticking

Abstract

A nozzle capable of preventing the adhesion of pipes and the bottom of the discharge hole, including a nozzle body, the nozzle body is reduced in diameter from the upper opening of the nozzle body to the vertical nozzle pipeline between the nozzle outlet at the lower part of the nozzle, and the nozzle body is in its There is an inverted triangle depression at the bottom of the nozzle below the nozzle outlet at the lower part of the nozzle; the nozzle outlet is chamfered at its molten steel spitting position; the nozzle pipeline is made of BN‑CaO‑Mg composite material on its inner pipe wall. Smear, bake after smearing before the tundish is used to form a high temperature resistant coating, in which Mg reacts to generate MgO high temperature resistant material, CaO and the generated Al 2 O 3 A low melting point product is produced, with the molten steel flowing out, while BN acts as a smooth inner wall, reducing inclusion adhesion. The invention can be widely used in the production process of continuous steel casting, can effectively reduce the cohesion and adhesion of non-metallic inclusions in molten steel, and has the characteristics of stable continuous casting.

Description

technical field [0001] The invention relates to the field of iron and steel metallurgical continuous casting, in particular to a nozzle structure that can prevent adhesion and is applied to the nozzle pipe of a continuous steel casting machine and the bottom of a discharge hole. Background technique [0002] At present, in the continuous casting production process of iron and steel metallurgical production enterprises, a submerged nozzle is often used. The function of the submerged nozzle is to guide molten steel from the tundish into the mold, and at the same time isolate the air to prevent oxidation. After a long period of operation, observation and feedback by the on-site workers, it is found that there are many problems in the process of using the submerged nozzle, as follows: [0003] 1. During the baking of the submerged nozzle, due to the presence of graphite inside the nozzle, the graphite (carbon) will be oxidized after baking, resulting in a decrease in the strengt...

AI Technical Summary

Problems solved by technology

[0003] 1. During the baking of the submerged nozzle, due to the presence of graphite inside the nozzle, the graphite (carbon) will be oxidized after baking, resulting in a decrease in the strength of the nozzle material, which is directly reflected in the fact that the bottom of the slag is prone to occur during use. the shedding;

[0004] 2. During the use of the submerged nozzle, since the position of the slag line of the nozzle is often in contact with the mold slag inside the crystallizer and reacts physically and chemically, the position of the slag line is easily eroded, and in severe cases, the slag line will break and the nozzle will be scrapped ;

[0005] 3. Due to the inevitable presence of oxidation inclusions in molten steel, nodular products are formed inside the nozzle, which affects the outflow of molten steel, causes bias current vibration, and also affects the service strength of the nozzle;

[0006] 4. When the molten steel flows from the tundish into the crystallizer, it passes through the submerged nozzle and the discharge hole. However, due to the fluid compression and diameter change, the fluid backflow is caused. After the backflow, the flow rate decreases, resulting in the oxidation of the molten steel. Aluminum inclusions will adhere in the pipe of the submerged nozzle, causing blockage of the pipe and discharge hole

[0007] In the prior art, for the above four problems, such as blowing argon gas, or adding anti-corrosion materials to the nozzle to alleviate the above problems, but at present, these measures only slow down and alleviate, but cannot completely solve

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