A method to match the low-speed pouring of extra-thick slab and the consumption of mold flux in continuous casting

Abstract

The invention relates to a method for matching low-speed pouring of an ultra-thick plate blank with consumption of continuous casting powder and belongs to the technical field of continuous casting powder of a steelmaking continuous casting crystallizer. The method comprises the following steps: by aiming at the carbon content of 0.15-0.2wt% in the medium carbon steel made of a 400mm ultra-thick plate blank, controlling the content of SiO2 in the continuous casting powder within a range of 28-34wt%, controlling the content of CaO within a range of 35-40wt%, controlling the content of Al2O3 within a range of 3.5-4wt%, controlling the alkalinity within a range of 1.25-1.26, controlling the viscosity within a range of 1.4-1.5 Poise, controlling the content of carbon within a range of 7.5-8wt% and controlling the melting point within a range of 1100-1130 DEG C, thereby being beneficial to increasing the consumption of the continuous casting powder; and meanwhile, according to practical production requirements, when a pouring speed of a plate blank is 0.7m / min, controlling the vibration frequency within a range of 145-155cpm, controlling the vibration amplitude within a range of 4.5-5.0mm and controlling the negative slip time within a range of 0.09-0.12s, thereby acquiring the consumption of continuous casting powder being 0.55-0.60kg / m<2> and the actual measured melt cinder thickness being 10-13mm. The method provided by the invention has the advantage that the balance between the consumption of continuous casting powder and the melting speed is effectively controlled.

Description

technical field [0001] The invention belongs to the technical field of continuous casting mold slag for steelmaking and continuous casting crystallizers, and in particular provides a method for matching the consumption of extra-thick slab (400mm) low casting speed and continuous casting mold slag. Background technique [0002] The basicity, viscosity, melting temperature and other physical and chemical performance indicators of slab continuous casting mold flux have been elaborated in many documents. Since the pouring speed of 400mm extra-thick slab is basically controlled within 0.7m / min, when casting speed When it is lower, the consumption of continuous casting mold slag is less. Experiments have shown that when the thickness of the liquid slag layer exceeds 16mm, the liquid slag is easy to form a sintered layer, and the fluidity of the continuous casting mold slag becomes poor, which is likely to cause the slag film to fall off and induce billet The shell forms microcrack...

AI Technical Summary

Problems solved by technology

[0002] The basicity, viscosity, melting temperature and other physical and chemical performance indicators of slab continuous casting mold flux have been elaborated in many documents. Since the pouring speed of 400mm extra-thick slab is basically controlled within 0.7m / min, when casting speed When it is lower, the consumption of continuous casting mold slag is less. Experiments show that when the thickness of the liquid slag layer exceeds 16mm, the liquid slag is easy to form a sintered layer, and the fluidity of the continuous casting mold slag becomes poor, which easily causes the slag film to fall off and induces microcracks

There are few studies on low-speed slab continuous casting mold flux, and there is no domestic experience for reference

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