A method for producing peritectic steel by a medium-thin slab continuous caster

Abstract

The invention discloses a method for producing peritectic steel by using a medium-thin slab continuous caster. The method comprises the following steps: converter steelmaking, external refining of an LF furnace, and continuous casting of the medium-thin slab continuous caster. According to the invention, the entire process of converter steelmaking, LF furnace refining and continuous casting of the medium-thin slab continuous caster is controlled, so that the crystallizer liquid level fluctuation range is controlled within + / -3 mm; the deoxidization and alloying of the steelmaking process are controlled to enable the steel inclusions to be mainly spessartine with low melting point and strong plasticity; in the refining process, the secondary oxidation of molten steel is reduced, and an argon system is designed reasonably to ensure the maximum flotation of the inclusions; during continuous casting, the pouring is protected, the secondary oxidation of molten steel is reduced, the properties of the inclusions in the molten steel are changed, and the pourability is improved, so that the mass normal stable production of peritectic steels by using the medium-thin slab continuous caster is realized.

Description

technical field [0001] The invention relates to the technical field of iron and steel metallurgy, in particular to a method for producing peritectic steel by a medium-thin slab continuous caster. Background technique [0002] Molten steel containing 0.09% to 0.17% by weight of C will undergo peritectic reaction (L+δ—γ) during solidification, resulting in volume shrinkage, and the higher the carbon content, the greater the cooling rate, and the greater the volume shrinkage . Since the presence of alloying elements will expand or shrink the γ phase region in the Fe-C alloy phase diagram, the C content required for peritectic reaction is also different for different steel types. [0003] The main problems encountered in the production of peritectic steel with low Mn / Si by medium and thin slab continuous casting machines are: 1. The crystallizer liquid level fluctuates too much, generally ±15mm; 2. Due to the low Mn / Si of this steel type , the inclusions generated in molten st...

AI Technical Summary

Problems solved by technology

[0003] The main problems encountered in the production of peritectic steel with low Mn / Si by medium and thin slab continuous casting machines are: 1. The crystallizer liquid level fluctuates too much, generally ±15mm; 2. Due to the low Mn / Si of this steel type , the inclusions generated in molten steel are mainly SiO 2 , poor pourability

[0004] Excessive fluctuations in the liquid level of the mold are the main causes of defects such as slag inclusions, pits, and longitudinal cracks on the surface of the slab, and even steel breakout accidents, which seriously affect the quality of peritectic steel products and the continuity of production

At present, most peritectic steel production enterprises adopt measures such as adjusting the casting speed, adjusting the secondary cooling water distribution system of the continuous casting machine, adjusting the pressure of the driving roller, or adjusting the composition of mold powder to solve the problem of excessive fluctuations in the mold liquid level. In the actual production process, only relying on the method of adjusting the process parameters of the medium and thin slab continuous casting machine cannot completely avoid the influence of excessive crystallizer liquid level fluctuations on the normal and stable production of peritectic steel in large quantities.