Refining process for obtaining solid Al2O3 inclusions

Abstract

The invention relates to a refining process for obtaining solid Al2O3 inclusions, which comprises the following steps of: controlling the addition of a deoxidizing agent in a converter tapping process, namely, not adopting aluminum deoxidization, and adopting silicon-manganese alloy and calcium carbide to carry out post-converter deoxidization, adjusting other chemical components except Al element in the components after tapping in place during tapping, and controlling the alkalinity of refining slag to be between 1.0 and 3.0; and in the refining heating process, the argon flow of ladle bottom blowing is controlled, the argon flow is smaller than 100 L / min, after the temperature of the molten steel meets the requirement, the Al content is adjusted in place at a time through an aluminum wire, so that solid Al2O3 inclusions are obtained, and the molten steel is transferred to an RH vacuum tank to be treated. According to the BOF-LF-RH-CC technological process production process adopted for the aluminum-containing steel, inclusions are controlled to be solid Al2O3 in the LF refining procedure, generation of low-melting-point calcium aluminate before the LF refining procedure is finished is effectively controlled, the Al2O3 inclusions are efficiently removed through RH vacuum, and it is guaranteed that the cleanliness of molten steel is high, and the inclusions are few.

Description

technical field [0001] The invention relates to the technical field of steelmaking, in particular to a method for obtaining solid Al 2 o 3 Refining process of inclusions. Background technique [0002] The Al element in aluminum-killed steel not only acts as a deoxidizer in the smelting process, but also refines the grains and improves the properties of the steel. In the production process of aluminum killed steel, the solid Al produced by aluminum deoxidation 2 o 3 It is easy to float and remove, especially in the process of vacuum treatment. A large number of studies have shown that Al 2 o 3 The removal efficiency of inclusions is extremely high. But in the smelting process, it is difficult to control the inclusions in the steel into solid Al 2 o 3 , especially during the refining process, calcium-containing alloys promote solid Al 2 o 3 The transformation of inclusions to calcium-aluminate inclusions and the reaction of slag-steel lead to the reduction of CaO in ...

AI Technical Summary

Problems solved by technology

In aluminum deoxidized steel, calcium aluminate with low melting point is easily formed, which causes the problem of excessive Ds inclusions

Control the inclusions into solid Al before the end of refining 2 o 3 It has become the subject of current research. In the prior art, generally by controlling the timing of alloy addition and the basicity of slag, the Al 2 o 3 The purpose of transforming inclusions into calcium aluminate is to realize the Al in steel before the end of refining. 2 o 3 However, this method is to add Al block after the furnace for deoxidation. During the refining process, Al is easy to reduce Ca in the slag, especially when the intensity of argon gas stirring is high, resulting in the end of refining. Inclusions transform to calcium aluminate, not all Al can be obtained 2 o 3 or Al 2 o 3 and a small amount of MgO inclusions

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