Buried oxygen blowing and decarburization process for electric-arc furnace steelmaking and control method

Abstract

The invention belongs to the technical field of ferrous metallurgy, and particularly relates to an oxygen blowing and decarburization process for electric-arc furnace steelmaking. An electric-arc furnace buried oxygen blowing direct decarburization way is adopted, i.e., an oxygen supply nozzle is arranged below a steel liquid level and oxidizing gas is sprayed from the lower side of a melting pool, so that rapid and controllable decarburization is realized. A control method for controlling oxidizing gas and protecting gas in a segmental way is adopted, a double-flow-channel spray pipe is taken as a nozzle, and the nozzle is made of a tungsten-copper alloy, stainless steel or a chromium or corundum tubular product. The gas (oxygen and carbon dioxide) flow of a central pipe of the nozzle is 100-3,500 Nm<3> / h, and the pressure is 0.2-0.8MPa; and the flow of ring slot gases (inertial gases such as carbon dioxide, natural gas, nitrogen gas or argon gas and the like) is 10-1,000 Nm<3> / h, and the pressure is 0.1-0.45MPa. Compared with a general oxygen blowing way, the oxygen blowing and decarburization process has the advantage that: oxygen is directly contacted with carbon element in molten steel, so that the speed and controllability of a decarburizing reaction are ensured.

Description

technical field [0001] The invention belongs to the technical field of iron and steel metallurgy, and in particular relates to an embedded oxygen-blowing decarburization process and a control method for electric arc furnace steelmaking. Background technique [0002] With the accelerated pace of steelmaking and smelting in electric arc furnaces, the consumption of smelting is reduced, and at the same time, the proportion of molten iron hot charging in electric furnaces increases, and the carbon content in molten pools increases. The existing steelmaking methods cannot meet the requirements of decarburization in molten pools. At present, the oxygen supply methods for electric arc furnace steelmaking mainly include furnace wall oxygen supply and furnace door oxygen supply. Their common features are: during the steelmaking process, the oxygen supply nozzle is located above the molten pool, and its vertical position from the molten steel surface is generally more than 200mm; the ...

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Problems solved by technology

[0011] The purpose of the invention is to overcome the low oxygen utilization rate, slow decarburization speed and poor control effect in the existing electric arc furnace steelmaking technology

The problem of low service life of electric arc furnace cover and flue gas system

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