High-lubrication slag-strip-free gettering crystallizer casting powder special for low-carbon moderately-thick slab

Abstract

The invention discloses high-lubrication slag-strip-free gettering crystallizer casting powder special for a low-carbon moderately-thick slab. The casting powder comprises, by weight, raw material components of 35%-46% of wollastonite, 10%-17% of quartz powder, 2%-7% of cryolite, 8%-15% of sodium carbonate, 1%-3% of magnesia, 5%-10% of fluorite, 2%-4% hydrophilia carbon, 3%-6% of graphite, 2%-5% of boron nitride and 3%-6% of manganese oxide. According to the high-lubrication slag-strip-free gettering crystallizer casting powder, the hydrophilia carbon is used so that the phenomena of carbon particle clotting can be effectively reduced, and carbon atoms are urged to be evenly dispersed to the maximum degree. The casting powder is small under a molten state and is formed and grows evenly, and smooth flowing in of liquid powder is fully guaranteed. The casting powder can timely absorb impurities in molten steel and react with the impurities to form low-melting-point matter which is taken away along with the casting powder, and larger slag strips can be avoided. Lubricating performance is great. The problem that molten steel solidification is not normal due to the fact that heat conducting is unstable is avoided, and then slag entrapment bleed-out, steel billet surface defects and the like can be avoided.

Description

technical field [0001] The invention belongs to the technical field of metallurgical auxiliary materials, and mainly relates to a high-lubrication and slag-free strip special for low-carbon medium-thick slabs to absorb mold slag. Background technique [0002] Continuous casting, that is, continuous steel casting, is a process that directly casts molten steel into shaped steel products through a continuous casting machine, which emerged in Europe and the United States in the 1950s following the traditional die casting method. In the 1980s and 1990s, the continuous casting technology was perfected day by day, and it has been used as the leading technology in the field of steel casting until now. [0003] With the increasing market demand for the quantity and quality of continuous casting slabs, iron and steel production enterprises urgently need to improve the quality and production efficiency of continuous casting, so high-efficiency continuous casting technology has emerged ...

AI Technical Summary

Problems solved by technology

In the high-efficiency continuous casting process, if you continue to use ordinary mold slag, the following problems will occur: (1) Due to the unsuitable slag forming speed, the controllability of liquid slag inflow will become poor

If the liquid slag flows in too much, it will cause the mold powder to be mixed; if the liquid slag flows in too little, insufficient lubrication will occur

(2) Mold slag does not spread well on the surface of molten steel in the mold, resulting in uneven melting at the meniscus of the mold during casting, resulting in excessive growth of slag

(3) There are many impurities in molten steel for low-carbon medium-thick slabs, and the refining effect is poor

The properties of the produced slag strips will change after absorbing alumina inclusions in the molten steel, and they will be easily drawn into the meniscus to change the heat flux density at the corner of the crystallizer, which is not conducive to the cooling and lubrication of the primary slab shell, and the heat transfer crack regulation function is poor. Cracks due to stress concentration