Refining method for preventing carbureting of molten steel in LF (ladle furnace) through utilizing argon plasmas

Abstract

The invention relates to a refining method for preventing carbureting of molten steel in an LF through utilizing argon plasmas, and belongs to the field of refining technologies in steelmaking in the metallurgical industry. A technical scheme is characterized in that a solid graphite electrode of the LF is replaced by a hollow graphite electrode, the center hole of the hollow graphite electrode is used to access argon to form an argon plasma arc, so direct contact of the electrode with air and the molten steel is avoided; and the generated plasma arc is used to heat, so the heating time is shortened, the hollow graphite electrode consumption is reduced, the carbureting of the molten steel in the refining process is mitigated, and the carbureting amount of the molten steel is controlled at below 0.005%. The method has the following positive effects: the argon plasma LF can combine all refining functions of present LF technologies, so it is easy to realize an argon plasma furnace from the LF; the generated argon plasmas have the advantages of high heating efficiency, slugging benefiting and the like; the heating period and the smelting period can be shortened; and electric energy is saved. By controlling the carbureting amount in the LF refining process, a decarburization function of RH or VD can be partially replaced, so the steelmaking operation is reduced, and the production cost is saved.

Description

technical field [0001] The invention relates to a refining method for preventing molten steel from increasing carbon in an LF furnace by using argon plasma, and belongs to the technical field of steelmaking and refining in the metallurgical industry. Background technique [0002] Conventional LF powered by solid graphite electrodes is one of the important out-of-furnace refining methods in the iron and steel metallurgy process. Due to its powerful refining function and flexible smelting cycle, it is an effective buffer link for steelmaking and continuous casting. However, when smelting low carbon steel and ultra-low carbon steel, carburization generally occurs in the LF refining process. According to literature, when smelting low-carbon steel (C: 0.04%-0.07%), the average carbon increase in the LF refining process can reach up to 0.033%. Therefore, when smelting low-carbon steel and ultra-low carbon steel, it is usually necessary to use Vacuum decarburization equipment such...

AI Technical Summary

Problems solved by technology

None of the above three methods can fundamentally solve the problem of carburization caused by the contact between molten steel and graphite electrodes, but can only alleviate the problem of carburization

Chinese patent application No. 200810118717.0 provides a method for preventing LF carburization. This method uses large argon gas stirring at the refining position to melt the slag. After the slag is completely melted, the lower electrode is used for heating, which can reduce the carburization of the LF refining process. amount to 0.023%; however, this method only reduces the contact time between the electrode and molten steel, and cannot fundamentally solve the problem of carburization

This process can lead to hydrogenation of molten steel and increase electrode consumption. At the same time, considering that H will cause hydrogen embrittlement and other adverse effects on steel quality and mechanical properties, it is a harmful gas element. This method is limited to laboratory research and is difficult in actual production. get applied in