Application of casting powder in high-casting-speed continuous casting peritectic steel

Abstract

The invention designs a casting powder application process capable of avoiding the defects of transverse and longitudinal cracks and the like on the surface of a casting blank when peritectic steel issubjected to high-pulling-speed continuous casting. The casting powder is used for peritectic steel high-casting-speed continuous casting. The casting powder is prepared from the following componentsin percentage by mass: 37%-40% of CaO, 28%-32% of SiO2, 0.5%-2% of Al2O3, 1%-4% of MgO, 1.0%-8% of MnO and Fe2O3, 3%-18% of Na2O, 2.0%-4.0% of Li2O, and 3%-15% of F<->, wherein the mass ratio of theMgO to the Al2O3 is (1-2):1, and in the casting powder, the ratio of binary alkalinity CaO to the SiO2 is 1.2-1.3. The average crystal size of a crystalline phase separated out of the casting powder is smaller than 8 microns, and the crystalline phase is single cuspidine, and the precipitated phase is uniformly distributed in the casting powder crystallization layer.

Description

Technical field [0001] The invention belongs to the field of steel smelting and continuous casting, and relates to a mold flux application process for avoiding defects such as transverse cracks and longitudinal cracks on the surface of a cast slab during high-speed continuous casting of peritectic steel. Background technique [0002] The carbon content of peritectic steel is 0.10-0.18%, and the peritectic reaction of L+δ→γ occurs during continuous casting, which is a crack-sensitive steel. Austenite is the most densely packed lattice structure and has the highest density. Its volume mass is smaller than that of ferrite and other phases. Therefore, the cast slab will cause a large volume shrinkage after austenite is formed in the peritectic reaction. , Resulting in uneven solidification of the initial blank shell, resulting in a stress gradient, and cracks occur at the thinner initial shell because it cannot withstand greater stress. Stress concentration during continuous casting...

AI Technical Summary

Problems solved by technology

Improving the crystallization ability of the mold flux can indeed control the heat transfer to a greater extent, but how to control the composition of the mold flux to obtain a dense and uniform crystal phase to improve the heat control ability of the mold flux and obtain a stable heat transfer process is the key to high casting speed. A major difficulty in the design of mold slag for continuous casting; in addition, the increase in the crystallization rate means that the thickness of the liquid slag layer is reduced. It is a contradiction between guaranteeing lubrication

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