Method for reducing corner cracks of medium-carbon boron-containing steel continuous casting sheet billet

Abstract

The invention discloses a method for reducing corner cracks of a medium-carbon boron-containing steel continuous casting sheet billet. The method mainly solves the technical problem that the corner crack defect of an existing medium-carbon boron-containing steel continuous casting sheet billet is difficult to control. The method for reducing the corner cracks of the medium-carbon boron-containing steel continuous casting sheet billet comprises the following steps of 1) adjusting the equipment precision of a straight arc-shaped continuous casting machine, and ensuring that the arc alignment precision of a crystallizer foot roller and a bent section is less than or equal to 0.15 mm; and (2) pouring the continuous casting sheet billet, specifically, adopting the straight arc-shaped continuous casting machine for pouring the sheet billet, enabling the superheat degree of tundish molten steel to be 15-25 DEG C, increasing the corner temperature in a weak cooling manner, enabling the water amount of the wide face of a crystallizer to be 3650-3850 L/min, enabling the water amount of the narrow face of the crystallizer to be 460-480 L/min, and controlling the temperature of the corners of the sheet billet before straightening to be 900 DEG C. By means of the method, titanium is adopted as an optimized alloy element, the equipment precision of the continuous casting machine is controlled, and the corner crack rate of the continuous casting sheet billet is smaller than or equal to 0.05%.

Description

technical field [0001] The invention relates to a production method of a medium-carbon boron-containing steel continuous casting slab, in particular to a method for reducing cracks at the corners of a medium-carbon boron-containing steel continuous casting slab, and belongs to the technical field of steelmaking and continuous casting. Background technique [0002] During the production process of continuous casting slabs with a boron content in the range of 0.0010-0.0030%, corner cracks are likely to occur, and the cracks are generally transverse. On the arc caster, the corner transverse cracks are usually formed on the inner arc side, while on the straight arc continuous casting machine, the corner transverse cracks may occur on the inner and outer arcs of the slab, and the length of the severe corner transverse cracks exceeds 10mm. Cracks extend from the wide face of the slab to the narrow face of the slab. There are some small cracks around the larger cracks. These small...

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Problems solved by technology

[0007] The purpose of the present invention is to provide a method for reducing the corner cracks of medium-carbon boron-containing steel continuous casting slabs, mainly to solve the technical problem that the existing medium-carbon boron-containing steel continuous casting slab corner crack defects are difficult to control

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