Method for reducing hot rolling burning loss of high-silicon electric steel

Abstract

The invention provides a method for reducing hot rolling burning loss of high-silicon electric steel. For a high-silicon electric steel casting blank with Si content of 1.5-3.5 wt%, four electric steel thin strips are respectively arranged between a casting roll and molten steel and between two narrow surfaces, and the molten steel flows space among the electric steel thin strips via a long nozzle from a tundish and is solidified to form a casting blank; the inside of the casting roll is fed with water and is cooled; and water-cooled jackets with water-cooling parts are arranged on outer sides of the four electric steel thin strips, the continuous casting speed is 0.5-3 m / min, the degree of superheat is 5-30 DEG C, and the molten steel is isolated from air by a protective atmosphere. A continuous casting machine does not have a crystallizer, so that costs for equipment and spare parts can be reduced, casting powder is saved, pollution of the casting powder to steel is reduced, degree of purity of the steel is improved, adhesion between the molten steel and the casting roll can be prevented, and the surface quality of the casting blank is improved. The electric steel thin strips adhered to the surface of the casting blank does not affect ingredients of a steel blank matrix, furthermore, oxidation of the casting blank in a followed-up heating process can be greatly reduced, hot rolling burning loss and surface defects are reduced, and yield of rolling is improved.

Description

technical field [0001] The invention belongs to the field of continuous casting process equipment, and in particular relates to a method for reducing hot-rolling burning loss of high-silicon electrical steel billets with a Si content of 1.5-3.5 wt%. Background technique [0002] High-silicon (Si 1.5-3.5%) electrical steel has poor thermal conductivity and high brittleness, and is prone to corner cracks during continuous casting, making continuous casting difficult. High-silicon electrical steel uses a continuous casting machine with a crystallizer to produce a slab with a thickness of 30-300mm, and then rolls after reheating in a heating furnace. [0003] Due to the high silicon content of the continuous casting slab, the casting slab of the traditional process oxidizes faster during the heating process. With the increase of the silicon content, the melting point of the oxide decreases, and a low melting point silicate is formed. The slab is easily deformed and hot rolled. ...

AI Technical Summary

Problems solved by technology

[0003] Due to the high silicon content of the continuous casting slab, the casting slab of the traditional process oxidizes faster during the heating process. With the increase of the silicon content, the melting point of the oxide decreases, and a low melting point silicate is formed. The slab is easily deformed and hot rolled. Many surface defects

Moreover, the oxides generated during the heating process flow to the bottom of the heating furnace in a liquid state, and long-term accumulation will affect the normal production

In addition, the high-silicon electrical steel oxidizes silicon during the heating process, resulting in desiliconization, while the thickness of the steel billet produced by the traditional process is large, and the reduction amount of each pass of hot rolling is limited, requiring multiple passes of rolling

Moreover, the rolling temperature drop is large, and as the temperature decreases, the brittleness of the steel increases, and the phenomenon of strip breakage occurs, which makes rolling difficult.

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