Preparation method of aluminum-calcium alloy used for vacuum refining molten steel deoxidation and device thereof

Abstract

The invention discloses a preparation method of aluminum-calcium alloy used for vacuum refining molten steel deoxidation and a device thereof; the high-purity aluminum and calcium are used as the raw material and are prepared according to the weight percent as follows: 70-90 percent of aluminum and 10-30 percent calcium; the calcium is added to the aluminum which is molten by a low-frequency sensing induction furnace, the aluminum and the calcium are molten for 30-40 minutes under the protection of argon gas and then cast into an ingot; after being cooled, the ingot is broken into blocks to prepare the aluminum-calcium alloy. The invention has the advantages that the alloy has high purity and high calcium content and is used for vacuum refining molten steel deoxidation; the deoxidation and calcium can be completed in one step; the O, C, N, S ingredients in the steel are ensured not to exceed the standard requirement; meanwhile, the Al2O3 inclusion content in the steel is greatly reduced, thereby having the obvious effects of reducing nodulation at a pouring water gap and improving steel quality.

Description

1. Technical field [0001] The invention relates to an alloy deoxidizer for smelting, in particular to a method and a device for preparing an aluminum-calcium alloy for deoxidizing molten steel in RH vacuum refining. 2. Background technology [0002] With the rapid development of the national economy, the demand for steel products in industries such as automobiles and home appliances is increasing, and the quality is also getting higher and higher. How to produce ultra-low carbon (C<30×10 -6 ), ultra-low nitrogen (N<30×10 -6 ), ultra-low oxygen (O<30×10 -6 ) and ultra-low sulfur (S<50×10 -6 ) steel has always been an important research topic of my country's iron and steel enterprises. [0003] At present, vacuum decarburization and deoxidation methods are generally used to produce the above-mentioned high-grade steel for automobiles and household appliances. The oxygen content in molten steel after vacuum treatment is very high (generally 200×10 for foreign m...

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Problems solved by technology

The reason is that the binder used in the briquetting is composed of hydrocarbons, and entering the steel together with the briquetting not only increases the carbon content, but also increases the hydrogen content, which is not allowed for high-end automobiles and home appliance steel; All the binders used contain water. When the aluminum powder and calcium powder are mixed with the binder, most of the calcium will be oxidized to calcium oxide quickly after meeting water, so that the content of metallic calcium in the briquette is very low, which cannot achieve the desired effect. Third, when this aluminum-calcium mixture is in a vacuum state of 1000 °C and 2 torr, the metal calcium in it will quickly become vapor and evaporate, and will be sucked away by the vacuum system, and cannot enter the steel.

[0012] The general remelting method is used to prepare aluminum-calcium alloys. If no other technical measures are added, even if high-purity metallic aluminum and metallic calcium are used as raw materials, it is difficult to produce aluminum with a calcium content of more than 8% due to the aforementioned characteristics of metallic calcium. calcium alloy

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