A continuous casting method for reducing large-size inclusions in the surface layer of aluminum-containing steel slabs

Abstract

The invention discloses a continuous casting method for reducing large-sized inclusions on the surface of an aluminum-containing steel casting billet, and belongs to the technical field of continuous casting. The continuous casting method for reducing large-sized inclusions in the surface layer of the aluminum-containing steel billet comprises the following steps: obtaining the billet after converter smelting, vacuum treatment, deoxidation alloying and continuous casting; controlling the immersion of the immersion nozzle during the continuous casting process Depth; the molten steel jet angle θ is controlled by controlling the nozzle structure parameters, so that the molten steel jet angle θ satisfies the formula tanθ≥(H‑h SEN ‑h port ‑100mm) / (1 / 2W‑d SEN ), where H represents the length of the crystallizer, mm; h SEN Represents the insertion depth of the immersion nozzle, mm; h port Represents the height of the nozzle outlet, mm; 100mm represents the distance from the molten steel surface to the top of the mold; W represents the width of the mold, mm; d SEN Represents the outer diameter of the immersion nozzle, mm. The continuous casting method for reducing the large-sized inclusions on the surface of the aluminum-containing steel casting billet according to the invention can reduce the number density of the slag and alumina inclusions on the surface of the casting billet, and reduce the occurrence rate of surface defects of the rolled sheet.

Description

technical field [0001] The invention relates to the technical field of continuous casting, in particular to a continuous casting method for reducing large-sized inclusions in the surface layer of aluminum-containing steel billets. Background technique [0002] With the increasingly fierce market competition, the surface quality requirements of high-quality cold-rolled steel sheets deoxidized by aluminum are becoming increasingly stringent. The large-sized inclusions distributed on the surface of the slab are deformed, crushed and distributed on the surface of the rolled plate during the rolling process, which affects the surface quality and coating performance of the rolled plate. Therefore, the distribution of inclusions on the surface of the slab must be strictly controlled during continuous casting of high-quality cold-rolled steel sheets. However, in the prior art, there is no method for reducing the content of large-sized inclusions in the surface layer of the slab. ...

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Problems solved by technology

[0003] The invention provides a continuous casting method for reducing large-size inclusions in the surface layer of aluminum-containing steel slabs, and solves or partially solves the technical problem in the prior art that there is no method for reducing the content of large-size inclusions in the surface layer of slabs

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