Method for increasing RH refining decarburization rate of ultra-low carbon steel and side blowing device

Abstract

The invention discloses a method for increasing the RH refining decarburization rate of ultra-low carbon steel and a side blowing device. The method comprises the steps that (1) the temperature of molten steel entering an RH station ranges from 1610 DEG C to 1630 DEG C, the carbon content ranges from 0.03 wt% to 0.05 wt%, and the oxygen content ranges from 0.025 wt% to 0.45 wt%; (2) after a steelladle is subjected to RH refining, the steel ladle is lifted for vacuumizing operation, and after the vacuum degree is reduced to 200 mbar or below, oxygen blowing decarburization operation of a descending top lance is carried out; the oxygen blowing flow is determined according to the oxygen content in the steel, and the oxygen blowing amount is determined according to the converter tapping amount, the oxygen content in the steel and the carbon content; and (3) when oxygen blowing of the RH top lance is finished, inert gas is blown to the side face of a vacuum tank till decarburization is finished. According to the method, oxygen blowing decarburization operation is also carried out when the carbon content is low, so that the decarburization rate of an RH refining furnace is greatly improved; by the adoption of the method, the carbon content in the steel can be reduced to 0.0012% or below within 12 min; the method has the characteristics of good decarburization rate, good decarburization effect, good molten steel cleanliness and the like.

Description

technical field [0001] The invention belongs to the technical field of ultra-low carbon steel smelting, in particular to a method and a side blowing device for increasing the decarburization rate of ultra-low carbon steel RH refining. Background technique [0002] At present, ultra-low carbon steel at home and abroad is generally produced by top-bottom combined blowing converter-RH vacuum refining-slab continuous casting process. There is a lot of carbon in the water to achieve the purpose of smelting ultra-low carbon or extremely low carbon steel. However, the common problems in the decarburization process of RH refining are that the decarburization time of RH refining is long, which leads to a series of problems such as long refining cycle, large process temperature drop, and difficulty in floating inclusions. In order to make up for the temperature drop in the RH refining process, some enterprises make up for it by increasing the end point temperature of the converter, b...

AI Technical Summary

Problems solved by technology

However, the common problem in the decarburization process of RH refining is that the decarburization time of RH refining is long, which leads to a series of problems such as long refining cycle, large temperature drop in the process, and difficulty in floating inclusions.

This study analyzed the main factors affecting the decarburization rate, but did not propose measures to effectively increase the decarburization rate of RH

[0008] It can be seen that among the existing measures to increase the decarburization rate of RH, the ability to increase the decarburization rate is limited, and some measures are also at the cost of polluting molten steel, so the feasibility of the measures is not great

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