Submerged nozzle with flared outlet and method of use thereof

Abstract

The application discloses a submerged nozzle with a trumpet-shaped outlet and its use method, which includes, from top to bottom: a nozzle chuck, a nozzle tapered section, a nozzle vertical section, and a trumpet-shaped outlet; the inner chamber of the nozzle chuck The upper inner diameter is 100-120mm, the lower inner diameter is 30-40mm, and the length is 60-80mm; the length of the tapered section of the nozzle is 360-500mm, and the lower inner diameter of the inner cavity of the tapered section of the nozzle is 20-30mm; The length of the vertical section of the nozzle is 180-220 mm, and the outer diameter is 60-80 mm; the radius of curvature of the trumpet-shaped outlet is 500-1500 mm, and the length is 90-110 mm. When the billet pulling speed is 2.4-2.8m / min, the nozzle insertion depth into molten steel is 110-120mm. When the nozzle erosion depth is ≥10mm, the nozzle is lifted up, and the insertion depth is changed to 90-100mm. The application can not only improve the utilization rate of the nozzle, but also stabilize the flow field in the crystallizer, which has direct significance to the improvement of the quality of the slab and the stable and smooth production.

Description

technical field [0001] The invention relates to the field of billet continuous casting, in particular to a submerged nozzle with a flared outlet and a method for using the same. Background technique [0002] The submerged nozzle for continuous casting mold is a refractory casing installed at the lower part of the tundish and inserted below the molten steel level of the mold to protect the casting refractory. It is the last refractory product used in the steelmaking-continuous casting process. : ①Isolate the contact between the molten steel and the air to prevent the secondary oxidation of the molten steel; ②Improve the flow state of the molten steel in the mold and promote the floating of inclusions; Improve the lubrication stability between the mold and the surface of the billet, promote the uniform solidification of the billet shell, and improve the surface quality of the billet. [0003] When the conventional nozzle is used for pouring, the impact force of the molten ste...

AI Technical Summary

Problems solved by technology

Due to the existence of negative pressure, the gap between the molten steel and the inner wall of the nozzle will suck air like an air pump, causing secondary oxidation of the molten steel and partial flow of the nozzle, affecting the quality of the continuous casting slab

[0005] During the production process, after the submerged nozzle is inserted into the molten steel, the slag line and the mold slag in the mold will have a long-term physical and chemical reaction, which will cause the nozzle to be severely eroded at the slag line. Replacing the nozzle will disrupt the production rhythm and affect Productivity

If the submerged nozzle breaks at the slag line, it may cause breakout of the slab shell, which will seriously affect the continuous casting production

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