Micro-carbon low-sulfur high-aluminum iron-free aluminum-magnesium-calcium alloy deoxidizer and preparation method and application thereof

Abstract

The invention discloses a micro-carbon low-sulfur high-aluminum iron-free aluminum-magnesium-calcium alloy deoxidizer and a preparation method and application thereof, and belongs to the technical field of metallurgy. The aluminum-magnesium-calcium alloy deoxidizer comprises the following chemical components in percentage by weight: 70-90% of Al, 1-10% of Mg, 5-25% of Ca, less than or equal to 0.02% of C, less than or equal to 0.02% of S and the balance inevitable impurities. The preparation method of the deoxidizer comprises the following steps: weighing a pure aluminum ingot, a magnesium metal and a calcium metal according to the chemical components of the aluminum-magnesium-calcium alloy deoxidizer, and adding the mixture into a resistance melting furnace for melting to prepare a moltenaluminum-magnesium-calcium alloy; and pouring the molten alloy into a continuous casting machine, and performing cooling and molding to prepare the aluminum-magnesium-calcium alloy deoxidizer. The deoxidizer can convert all or most of an deoxidized product Al2O3 into calcium aluminosilicate (7Al2O3. 12CaO) with a low melting point (1400 DEG C), and the calcium aluminosilicate (7Al2O3. 12CaO) floats on the surface of molten steel to be removed, so that the harmful effect of Al2O3 is reduced to the maximum extent, and the quality of steel is remarkably improved.

Description

technical field [0001] The invention relates to the technical field of metallurgy, in particular to a micro-carbon, low-sulfur, high-aluminum, iron-free, aluminum-magnesium-calcium alloy deoxidizer and a preparation method and application thereof. Background technique [0002] Since the beginning of the 20th century, my country's steelmaking process has undergone fundamental changes, and the follow-up processing has also continued to extend, forming a hot metal pretreatment → top-bottom combined blowing converter steelmaking → LF, RH refining → continuous casting → hot rolling → cold rolling →Galvanizing→Coating a complete process route. At the same time, the proportion of deep-drawing steel and ultra-deep-drawing steel (such as automobile surface plate steel, container steel, etc.) is also increasing. [0003] For the smelting of low-silicon and low-carbon aluminum-killed steel used to produce thin-gauge cold-rolled deep-drawing products, metal aluminum (or aluminum-iron al...

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Problems solved by technology

[0006] In addition, the preparation method of the alloy is to make aluminum-calcium master alloy and aluminum-magnesium master alloy with low-frequency induction furnace first, and then use power frequency induction furnace to melt into finished products. Because the alloy contains about 50% Fe, it determines The melting temperature needs to reach about 1500°C. It is quite difficult to melt metal calcium and metal magnesium into the alloy at such a high melting temperature, because calcium has a low melting point (839°C) and a low boiling point (1450°C). , low density (1.54g / cm 3 ), the melting point of metal magnesium is low (651°C), and the density is small (1.74g / cm 3 ), before the metal calcium, metal magnesium and aluminum ingots are fully combined, most of the calcium and magnesium will be vaporized, volatilized and oxidized from the molten aluminum during the smelting process, and it is impossible to obtain an alloy with high calcium content. Although the method of preparing the intermediate alloy is adopted first and there is argon protection in the casting process of the industrial frequency furnace production process, it is extremely difficult to control the burning loss of Ca and Mg and the operation is complicated. At the same time, a second production process is added, that is, the production of aluminum Calcium master alloys and the preparation of aluminum-magnesium master alloys increase the production cost too much. Even so, the vaporization, volatilization and oxidation burning loss of Ca and Mg in the melting process of industrial frequency furnaces are still relatively large, reaching 5%, causing production Costs have risen sharply

Therefore, the preparation method is relatively difficult, uneconomical and unstable, and does not adapt to the requirements of industrialized mass production.

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