CN103205535A - Method for controlling silicon return for steel with lower silicon content - Google Patents

Abstract

The invention relates to a method for controlling silicon return for steel with lower silicon content. The method is characterized by: using an aluminum base composite deoxidizer consisting of Al and Al2O3 at station of a refining ladle furnace, wherein the components in percentage by weight are as follows: 10-45% of Al, 55-90% of Al2O3, and the balance of impurity elements; and adding the aluminum base composite deoxidizer with an amount of 0.3-1.0kg per ton of steel. The method has the advantages that the aluminum base composite deoxidizer consisting of Al and Al2O3 not only meets the demand of deoxidization of molten steel, but also decreases silicon in molten steel. Silicon increased in molten steel does not exceed 0.01wt%. Beneficial condition is provided for production of low silicon steel, and the demand of steel components is met.

Description

The low steel of a kind of silicone content is controlled back the method for silicon

Technical field

The present invention relates to the low steel of a kind of silicone content and control back the method for silicon, belong to the field of steel-making that metallurgical industry is produced.

Background technology

When producing the lower steel grade of silicone content, prevent that molten steel from increasing silicon is a very important problem.Produce this class steel (as: ML08Al requires silicone content in the steel≤0.06%) if the phenomenon that silicone content exceeds standard, will change steel grade even return that stove is disconnected to be watered, bring very big problem for the organization of production of enterprise.

The production technique of this type of low-silicon steel is generally: converter → LF refining furnace → continuous casting.Molten steel need carry out the deoxidation of molten steel in refining furnaceman LF position, and reductor generally is divided into silicon reductor and aluminium deoxidizer.Owing to produce low-silicon steel, if adopt the silicon reductor, make molten steel increase silicon probably, cause silicone content to exceed standard, therefore the general low-silicon steel of producing adopts aluminium deoxidizer.But aluminium deoxidizer is a kind of strong reductor, the SiO in meeting and the refining slag ₂Reaction, thus the Si element reduction of generation exceeds standard the molten steel silicone content in molten steel, adopts general aluminium deoxidizer, will increase silicon 0.02-0.04 wt % in the molten steel at least.

The measure that silicon is returned in existing control mainly contains:

According to " continuous casting " the 5th phase in 2008 " the ASP flow process is produced the control techniques of low-silicon steel water ", the major measure that Jinan Iron ﹠ Steel Group Corp's the 3rd steelworks control molten steel returns silicon is: strengthen the pushing off the slag effect, reduce the quantity of slag and the flexible technologies such as deoxidation, Argon of adjusting under the converter.

According to " Xinjiang iron and steel " the 3rd phase in 2007 " production practice of low-carbon low-silicon steel (SPHC) electric furnace ", Xinjiang Ba Yi Iron ﹠ Steel Co., Ltd. when producing low-silicon steel, the raw-material silicone content of strict control, the SiO in the general requirement slag ₂≤ 2.5%.

According to " Shandong metallurgy " the 6th phase in 2006 " exploitation and the application of Ji steel low-carbon low-silicon steel smelting technology ", take to reduce slag under the converter, control adds the method for aluminium and control refining time, has reduced the silicon that returns of molten steel.

Summary of the invention

The purpose of this invention is to provide and a kind ofly control the method that the low steel of the silicone content that increases the silicon amount in the molten steel is controlled back silicon by composition and addition at refining furnaceman LF position design reductor.

Generally speaking, in refining furnaceman LF position, there are following reaction in molten steel and slag:

[Al]+（SiO ₂）=（Al ₂O ₃）+[Si]

Wherein, [Al]---the activity of aluminium in the expression molten steel, %

(SiO ₂)---SiO in the expression slag ₂Activity

[Si]---the activity of silicon in the expression molten steel, %

(Al ₂O ₃)---Al in the expression slag ₂O ₃Activity

By following formula as seen, the Al in the increase slag ₂O ₃Can prevent that then molten steel from increasing silicon.

Accordingly, the invention provides following technical scheme:

Adopt by Al and Al in refining furnaceman LF position ₂O ₃The aluminium base composite deoxidant of forming, its composition by mass ratio is: the content of Al is 10-45%, Al ₂O ₃Content be 55-90%, all the other are impurity element; Add-on is the 0.3-1.0kg/t steel.

Advantage of the present invention is: adopt by Al and Al ₂O ₃The aluminium base composite deoxidant of forming had both satisfied the requirement of deoxidation of molten steel, and it is less to make molten steel increase the silicon amount again, increases silicon in the molten steel and is no more than 0.01wt%, thereby for the production of low-silicon steel provides favourable condition, satisfied the requirement of steel grades.

Embodiment

Embodiment 1: the silicone content of the initial molten steel of refining LF stove is 0.04 wt %, and the molten steel amount is 93t.Al content is 36.6 wt %, Al in the aluminium base composite deoxidant composition that adds ₂O ₃Content be 62.3 wt %, all the other are impurity, add-on is 40kg.The silicon amount that increases of molten steel is 0.006 wt %.

Claims (1)

1. a silicone content hangs down the method that steel is controlled back silicon, it is characterized in that: adopt by Al and Al in refining furnaceman LF position ₂O ₃The aluminium base composite deoxidant of forming, its composition by mass ratio is: the content of Al is 10-45%, Al ₂O ₃Content be 55-90%, all the other are impurity element; Add-on is the 0.3-1.0kg/t steel.