Method for producing low-alloy peritectic steel by medium-thickness slab caster

Abstract

The invention provides a method for producing low-alloy peritectic steel by a medium-thickness slab caster, which comprises the following steps: firstly, converter smelting: alkalinity of molten steel is increased during the tapping, top slag is modified after the tapping so as to realize the tapping without slag, tapping final phosphorus is controlled within ingredient range, and other ingredients are lower than the upper limit value; secondly, LF furnace refining: deep deoxidation is performed, the mixing is performed by adopting argon; thirdly, casting: the casting is performed by adopting the medium-thickness slab caster, the slag is protected by adopting a high-alkalinity crystallizer with high melting speed, and the blowing argon protection of the crystallizer is realized. The method for producing the low-alloy peritectic steel lightens the fluid level fluctuation caused by peritectic reaction during the casting production, eliminates longitudinal division and transverse depression on the surface of a low-alloy peritectic steel casting blank so that the qualification rate of the casting blank reaches 100 percent, and fully develops the capacity of the medium-thickness slab caster producing the low-alloy peritectic steel massively at high pulling rate.

Description

Technical field [0001] The invention belongs to the technical field of iron and steel metallurgy, and in particular relates to a method for producing low-alloy peritectic steel using a medium-thickness slab continuous casting machine. Background technique [0002] The traditional production method of low-alloy peritectic steel is in the form of die casting. After the industrial production of continuous casting in the late 1970s, it experienced the great development period of continuous casting in the 1980s and 1990s. The traditional continuous casting machine also appeared in casting. Production experience of peritectic steel. However, for the continuous casting machine with medium thickness (80~150mm), due to its fast drawing speed, thin casting billet, small nozzle inner diameter, and large fluctuation of the mold liquid level, if the low-alloy peritectic steel is produced according to the traditional continuous casting machine The method cannot meet the production and quality ...

AI Technical Summary

Problems solved by technology

However, for medium-thickness (80-150mm) continuous casting machines, due to the characteristics of fast casting speed, thin casting slab, small nozzle inner diameter, and large crystallizer liquid level fluctuations, if the traditional continuous casting machine is used to produce low-alloy peritectic steel method, it cannot meet the production and quality requirements of the medium-thickness continuous casting machine

Transferring the method of producing low-alloy peritectic steel from the traditional continuous casting machine to the current medium-thickness continuous casting machine, [C] ranges from 0.09% to 0.15%, and the δFe+L (liquid)→γFe peritectic reaction occurs , the occurrence of this reaction makes the slab shell in the crystallizer shrink a lot, and the air gap between the slab shell and the slab is formed early and large, and the heat flow transfer is hindered, resulting in the uneven shell of the slab and the formation of longitudinal cracks on the surface; the formed After the thin shell comes out of the mold, it is pressed at the roller to form a bulge, which causes the liquid level to fluctuate greatly, and then forms a transverse depression at the mold vibration mark due to the fluctuating liquid level

Therefore, using a medium-thickness continuous casting machine cannot guarantee the mass production of low-alloy peritectic steel at a high casting speed, and it is also impossible to give full play to the high-efficiency performance of this high-speed casting machine