Temperature and cleanliness controlling method for production of steel liquid of low-carbon steel and ultra-low carbon steel

Abstract

The invention discloses a temperature and cleanliness controlling method for production of steel liquid of low-carbon steel and ultra-low carbon steel, and belongs to the field of steel and iron metallurgy. The method disclosed by the invention comprises the following steps: adding aluminum products such as aluminum granules, aluminum ingots and aluminum alloys into the steel liquid in a steel ladle or in a tapping process before tapping of a converter so as to ensure that the aluminum products react with oxygen in the steel liquid and heat is released, and thus the temperature of molten steelis increased; simultaneously reducing oxidizability of furnace residues; controlling the added aluminum to ensure that the total aluminum products react with the oxygen in the tapping steel liquid and the aluminum content in the tapping steel liquid is less than 50*10<-6>; and basically floating and removing generated Al2O3 before entering into RH refining. When RH refining is performed and the vacuum degree of a vacuum tank is less than 20-50kPa, forced oxygen blowing and decarbonization can be carried out by adopting a top lance, so that the RH decarbonization efficiency is ensured; and meanwhile, after control of the decarbonization is finished, the oxygen content is less than 400x10<-6>, so that the phenomenon that the molten steel is higher in cleanliness after RH refining is performed is ensured. According to the method disclosed by the invention, the temperature of the steel liquid can be increased, the problem of insufficient temperature in RH decarbonization and refining processes in steel plants is solved, and meanwhile, the oxygen blowing amount for RH refining forced decarbonization can be controlled more accurately, the terminal oxygen content for RH decarbonization is controlled and reduced, and the cleanliness of the steel liquid is improved.

Description

technical field [0001] The invention relates to the field of iron and steel metallurgy, in particular to a method for controlling the temperature and cleanliness of molten steel in the production of low-carbon steel and ultra-low-carbon steel in a converter-RH refining process, through the exothermic reaction of aluminum and oxygen in the tapping process, the molten steel is Heating to make up for the low-carbon steel and ultra-low-carbon steel intermediate converter tapping temperature and the large temperature drop in the RH refining process, and to reduce the oxidation of slag. 2 o 3 The inclusions are basically removed by floating before RH refining, and will not have adverse effects on the cleanliness of molten steel at the end of RH refining; during the decarburization process of RH refining, the forced oxygen blowing decarburization process of the top lance is used to control the amount of oxygen blowing more accurately, and Reducing the oxygen content at the end point...

AI Technical Summary

Problems solved by technology

[0005] The invention provides a method for controlling the temperature and cleanliness of molten steel of low-carbon steel and ultra-low-carbon steel produced in the converter-RH refining process. Before tapping the converter, in the ladle or during the tapping process, according to the oxygen content in the molten steel, The demand for temperature rise and the control of nitrogen content require adding a certain amount of aluminum or aluminum alloy to molten steel, using the heat of aluminum-oxygen reaction to increase the temperature of molten steel, and solving the problems of insufficient tapping temperature in the converter and excessive temperature drop in the RH process to meet the temperature requirements of the molten steel in subsequent processes. Requirements, and reduce the oxidation of slag; at the same time, the Al 2 o 3 The inclusions are basically removed by floating before RH refining, which is beneficial to the control of the cleanliness of molten steel; during the decarburization process of RH refining, the forced decarburization of the top gun is used, which can more accurately control the amount of oxygen blown in, and more accurately control and reduce the oxygen content at the end of RH decarburization , the cleanliness of molten steel is significantly improved

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