Magnesium-calcium alloy cored wire for ferrous metallurgy and preparation method of magnesium-calcium alloy cored wire

Abstract

The invention discloses a magnesium-calcium alloy cored wire for ferrous metallurgy and a preparation method of the magnesium-calcium alloy cored wire. The magnesium-calcium alloy cored wire is composed of a core material and a sheath. The core material is composed of magnesium, calcium and silicon and is prepared from 6%-38% of Mg, 5%-30% of Ca and the balance silicon and inevitable impurity elements during raw material preparation; and preferably, the mass ratio of Mg to Ca is controlled to be between 5:3 and 7.5:3. For gear steel, free-cutting steel and non-quenched and tempered steel, the morphology of Al2O3 inclusion and MnS inclusion and the cleanliness of molten steel can be improved through Ca, and the morphology of the inclusion and the cleanliness of the molten steel can also be improved through Mg; the functions of inclusion denaturation and molten steel purification can be achieved at the same time through magnesium-calcium composite treatment; and the effective function of Ca can be remarkably improved through Mg, and the yield of Ca can be remarkably increased through Mg. The cored wire is fed during refining, and the functions of deoxidization, inclusion modification, molten steel purification and steel performance improving can be achieved.

Description

technical field [0001] The present invention relates to various additive materials added to molten steel or molten iron and its preparation method, in particular to a composite material additive in the form of a cored wire used in iron and steel metallurgy and its preparation method, which is applied to metal material inclusions Morphological control technology field. Background technique [0002] Gear steel, free-cutting steel, and non-quenched and tempered steel usually contain a certain amount of sulfur. Aluminum deoxidation is mainly used in smelting, and the product Al 2 o 3 The inclusions are clustered, and its melting point is as high as 2050 ° C. It is solid at steelmaking temperature. Due to its strong intermolecular bonding force, Al 2 o 3 It is easy to adhere to the wall of the nozzle, accumulate and grow nodules, which will cause the blockage of the nozzle; when the steel is processed, it is distributed in chains or strings in the steel, which deteriorates the...

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Problems solved by technology

[0005] At 1600°C, the melting point of magnesium is 649°C, the boiling point is 1090°C, the melting point of calcium is 839°C, and the boiling point is 1484°C. Under the temperature conditions of steelmaking and refining, the vapor pressure of magnesium and calcium is very high. Adding magnesium and calcium to molten steel will cause magnesium and calcium to quickly generate steam and escape, which cannot be directly added to steel. Moreover, after calcium and magnesium steam contact with molten steel at high temperature, it will cause violent combustion and explosion, causing molten steel to splash Accidents, at the same time directly adding magnesium and calcium to molten steel consumes a lot, and the metallurgical process cost of controlling inclusions is high. Magnesium-calcium is usually added to molten steel in the form of alloy cored wire, mostly silicon-calcium alloy wire and silicon-magnesium alloy wire. Add in the form of alloy wire, but feed the wire into the molten metal by adding two kinds of alloy wire, which is not conducive to the precise control of the alloy composition

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