Fluoride-free molten steel purifying agent and preparation method thereof

Abstract

The invention discloses a fluoride-free molten steel purifying agent and a preparation method thereof, and relates to the technical field of steelmaking. The fluoride-free molten steel purifying agent is a composite sphere, the composite sphere is composed of an inner core and an outer shell, the inner core is composed of diatomite, aluminum nitride, Ba-Ti alloy and a silane coupling agent, the outer shell is composed of calcium carbonate, magnesium carbonate and a composite binder, and the mass ratio of the inner core to the outer shell is (1-2): (0.5-2). According to the fluoride-free molten steel purifying agent, raw materials are easy to obtain, the preparation method is simple and easy to operate, the cost is low, inclusions in molten steel can be quickly removed, the functions of slagging, deoxidation, desulfurization and dephosphorization are achieved, and the purification degree of the molten steel is greatly improved; and the diatomite is effectively utilized to purify the molten steel, the production cost is greatly reduced, and the purposes of energy conservation and environmental protection are achieved.

Description

technical field [0001] The invention belongs to the technical field of steelmaking, and in particular relates to a fluorine-free molten steel purifying agent and a preparation method thereof. Background technique [0002] With the rapid development of economic construction, the development of industries such as national defense, transportation, petroleum and automobiles, and the advancement of technology, the requirements for steel performance are becoming increasingly stringent. In order to meet the needs of high strength, long life, corrosion resistance and adapt to work in harsh environments, the purity, uniformity and fine grain size of petroleum casing, deep-drawing sheet, high-quality pipeline steel and welding rod steel The requirements for globalization are getting higher and higher, and the market has higher and higher requirements for steel quality, especially for purity. Ensuring the purity of steel mainly refers to reducing the content of impurity elements in st...

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Problems solved by technology

[0004] Chinese invention patent CN201410715201.X discloses a molten steel purifying agent in the form of a composite sphere and its production method. The composite sphere is composed of a pellet core and a shell. The pellet core is made of metal, and the shell is carbonate. It enters the molten steel and bursts. It can produce tiny particles in liquid phase and gas phase at the same time, which can promote the accumulation and removal of inclusions and be removed by bubble collision, so that the cleanliness of molten steel is greatly improved, but the raw materials of the purifier are metal, metal alumina and carbonate, these The cost of raw material preparation is high, the pollution is serious, the cost of molten steel treatment is increased, and the environmental pollution is further increased, which does not conform to the concept of modern social development

Chinese invention patent CN201710696763.8 discloses a preparation method of a fluorine-free low-titanium molten steel purifier (refined material). The method adopts at least one of natural wollastonite, quartz and calcium carbonate as a raw material for melting. The method The raw materials are easy to obtain, and have the ability to effectively deoxidize and desulfurize. However, the purification agent needs to be prepared at a melting temperature of 1300-1650°C during the preparation process, which requires high energy consumption, and natural wollastonite and quartz contain more impurities. , will affect the quality of fluorine-free low-titanium steel