A kind of killed steel deoxidation method

Abstract

The invention discloses a killed steel deoxygenation method and belongs to the technical field of ladle refining. The killed steel deoxygenation method is characterized by comprising the following steps of slag washing, refining, slag electrification, deoxygenation, acceleration of steel slag interface reactions and soft blowing. According to the deoxygenation step, a deoxidizing agent comprises silicon carbide and calcium carbide, 70% of silicon carbide is added firstly, then calcium carbide is added, and then 30% of silicon carbide is added. Compared with the prior art, the killed steel deoxygenation method has the characteristics of being good in product deoxygenation effect, greatly reducing the deoxygenation cost and being stable in product quality.

Description

technical field [0001] This invention is a divisional application of the invention patent application "A Low-Cost Silicon Carbide Deoxidation Method" (Application No.: 201410539640X), which relates to the field of LF refining technology, especially a low-cost refining technology suitable for deoxidation of killed steel. Background technique [0002] According to the degree of deoxidation during smelting, steel is divided into boiling steel, semi-killed steel and killed steel. In continuous casting, it needs to be completely deoxidized killed steel. In the prior art, CaO-CaF is used when smelting non-low silicon aluminum killed steel. 2 Refining slag system, the slag system increases with the increase of CaO, the viscosity of the slag increases, the slag has a high alkalinity, and there is no SiO 2 The slag material neutralizes the alkalinity of the slag. [0003] This process has the following defects in application: ①CaF 2 The main function is to improve the fluidity of ...

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Problems solved by technology

[0003] This process has the following defects in application: ①CaF 2 The main function is to improve the fluidity of slag, reduce the melting point of slag, increase the diffusion rate of desulfurization products, improve the kinetic conditions of desulfurization, thereby adjusting the viscosity of slag, but can not adjust the alkalinity. Severe erosion of furnace lining and ladle slag line; at the same time, the viscosity of this slag system is small, which is not conducive to submerged arc operation, resulting in radiation erosion of the arc to the lining; in addition, CaF 2 It will also react with other components in the slag to generate fluorine-containing gas that will pollute the environment; ② single calcium carbide (CaC 2 ) diffusion deoxidation method, as the amount of slag increases, the amount of calcium carbide increases significantly, while the price of calcium carbide remains high, which squeezes the profit margins of steel companies and seriously affects the economic benefits of enterprises; ③ When deoxidizing killed steel, the slag at the end of refining is white slag Finally, feed the metal calcium wire to denature the deoxidation product, which will increase additional costs; ④Single calcium carbide is used as LF deoxidizer, and the sampling inspection of casting slab inclusions grade ≥ 3.0 is 4.3 times per month on average, indicating that the number of inclusions is large. The inclusions are mainly sulfide inclusions and oxidized inclusions, a small part of the sulfide inclusions and oxidized inclusions gather in the segregation area, most of the sulfide inclusions and oxidized inclusions are due to the unreasonable deoxidation system, and the inclusions in the molten steel are not fully denatured and removed, resulting in the casting slab There are many inclusions grade ≥ 3.0, which affects the quality of the end product and increases the economic loss of the enterprise

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