Low-cost high-alkalinity mold powder for continuous casting peritectic steel

Abstract

The invention provides low-cost high-alkalinity crystallizer casting powder used for continuous casting peritectic steel. The casting powder is prepared by mixing a matrix and a carbon material, wherein the weight of the carbon material accounts for 3.0-8.0% of the total weight of the matrix. The matrix is prepared from, by weight, 9-14.0% of Na2O, 9.5-14.0% of F- , MgO with the weight percentage smaller than or equal to 4.0%, 44.0-49.0% of CaO, 23.0-29.0% of SiO2, 2.5-5.0% of Al2O3 and Fe2O3 with the weight percentage smaller than or equal to 3.0%. The crystallizer casting powder is high in crystallizing capacity, has low melting point and viscosity and moderate solidification temperature and can eliminate longitudinal cracks in the surface of a peritectic steel slab in safe and smooth production, a control heat transfer function and a lubricating function of the casting powder are effectively coordinated, little or no Li2O is contained in the components, and therefore the casting powder is low in cost.

Description

technical field [0001] The invention belongs to the technical field of continuous casting crystallizer mold powder, in particular to low-cost high-alkalinity crystallizer mold powder for continuous casting peritectic steel. Background technique [0002] Continuous casting mold flux is a key auxiliary material in the continuous casting process, which has an important impact on the continuous casting process and the control of the surface quality of the slab. During the continuous casting process, it is continuously added to the surface of molten steel in the crystallizer, and the molten slag flows into the gap between the crystallizer and the billet shell. The main functions of mold slag are thermal insulation, preventing oxidation of molten steel, absorbing inclusions in steel, lubricating the slab and controlling heat transfer, among which controlling the heat transfer from the slab to the mold and lubricating the moving slab are the most important of the mold slag effect....

AI Technical Summary

Problems solved by technology

[0005] Chinese patent CN101898232A discloses a continuous casting mold flux for continuous casting of manganese-containing low-alloy steel with wide and thick slabs, the basicity of which is 1.65-1.75, Li 2 O is 4.0-5.0%, the cost is high, and because its solidification temperature is low at 1130-1150 °C, even if its crystallization performance is strong, due to the thin solid slag film, the thermal resistance of the slag film is not large, and the meniscus cannot be effectively reduced surface area heat flux, and field statistics show that the effect of controlling longitudinal cracks is still not obvious

Chinese patent CN104707958A discloses a high-alkalinity continuous casting mold flux for casting peritectic steel, which contains more Li 2 O, the cost of mold flux is very high, and the industrial application is limited

Chinese patent CN103317112A discloses a high-basicity mold powder for peritectic steel continuous casting and its preparation method. Although it does not disclose the specific proportion of alkali metal oxides, it is configured and tested according to the published mold powder components, and it is found that The mold flux contains Li 2 O≥1.0%, otherwise the designed performance cannot be achieved, so the cost of the mold flux is also high

Therefore, as the price of lithium carbonate doubles, the cost of high-alkalinity continuous casting mold flux for peritectic steel continues to rise, and large-scale industrial application is becoming more and more difficult

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