Method for quick deoxidization in smelting process of ladle furnace (LF)

Abstract

The invention discloses a method for quick deoxidization in the smelting process of a ladle furnace (LF). The method comprises the following steps: (1) adding aluminum iron containing 40% of aluminumat a time after molten steel enters the ladle furnace (LF), so that the aluminum content in the molten steel reaches 0.04%-0.05%, and adding 150 kg of low aluminum slag balls, and 2-2.5 kg of active lime per ton of steel; (2) powering on and slagging, powering on for 3-5 times, adding 0.2 kg of molten steel deoxidizing agents per ton of steel, powering on for 5 min, melting top slag, and then powering off; (3) adjusting argon gas flow such that the diameter of the slag face blown by argon gas is 450-500 mm, adding 1-1.5 kg of the low aluminum slag balls per ton of steel, and 0.4 kg of the molten steel deoxidizing agents per ton of steel, stirring the mixtures for 15-20s, and then adding 1-1.5 kg of the low aluminum slag balls per ton of steel and 0.4 kg of the molten steel deoxidizing agents per ton of steel if the deoxidization effect is poor; stirring the mixtures for 15-20s, till the section of the top slag is yellowish white, namely that the deoxidization is finished; and adjustingthe argon gas flow to 100-150 L / min in time, and performing subsequent operation. According to the method disclosed by the invention, not only the quick deoxidization of molten steel in the smeltingprocess is achieved, the output of inclusions in the smelting process is reduced, and the quality of steel billets is improved, but also the thermal efficiency in the power-on heating process is improved, and the power consumption and slag consumption are reduced.

Description

technical field [0001] The invention belongs to the technical field of steelmaking, in particular to a method for rapid deoxidation in the smelting process of an LF refining furnace. Background technique [0002] Deoxidation in the LF refining process includes two aspects: 1. Deoxidation of molten steel. The deoxidation of molten steel is mainly based on precipitation deoxidation. That is, adding deoxidized alloys, such as aluminum-iron alloys or aluminum particles, to the molten steel, and blowing argon gas at the bottom of the ladle to complete the process. Deoxidation of molten steel; 2. Deoxidation of the top slag, generally by adding a deoxidizer to the top slag, such as calcium carbide powder, carbon powder and ferrosilicon powder. The deoxidation of molten steel in LF furnace is one of the main tasks of molten steel refining. Within a certain period of time, the lag of deoxidation of molten steel and top slag will bring a series of adverse effects on the quality of mo...

AI Technical Summary

Problems solved by technology

The deoxidation of molten steel in LF furnace is one of the main tasks of molten steel refining. Within a certain period of time, the lag of deoxidation of molten steel and top slag will bring a series of adverse effects on the quality of molten steel and the smooth flow of production. For example, steel The deoxidation of the liquid is delayed, resulting in more inclusions, the deoxidation of the top slag is delayed, the adsorption capacity of the inclusions in the molten steel is weak, and a large number of inclusions remain in the molten steel, resulting in more and more inclusions bonded to the nozzle of the continuous casting tundish. The more the nozzle is blocked, the production will be interrupted, and a series of production costs will increase. The original deoxidation technology achieves the purpose of deoxidation by increasing the amount of aluminum, iron and deoxidizer. However, for converter tapping slag or overblown furnaces, the deoxidation effect is not obvious, and the amount of deoxidizer added is not dispersed in time, and local deoxidation is strong, resulting in slag turning or steel turning, which also brings hidden dangers to the safe use of equipment. The tundish nozzle is blocked due to the lag, the composition is excessively extracted, and the cost increases sharply. A new deoxidation method is needed to achieve rapid deoxidation, stabilize the chemical composition of molten steel, ensure the smooth operation of the continuous casting machine, and save costs.