Method for producing low-carbon low-silicon ultralow-sulfur steel by adopting LF single-link process

Abstract

The invention discloses a method for producing low-carbon low-silicon ultralow-sulfur steel by adopting an LF single-link process. The method comprises the following steps of carrying out desulfurization and slagging-off pretreatment on molten iron to obtain pretreated molten iron; smelting the pretreated molten iron, low-sulfur waste steel and auxiliary materials, and obtaining smelted molten steel, wherein in the smelting process, the oxygen blowing time is controlled to be 13-15 min, the oxygen blowing amount is controlled to be 46-52 Nm<3> / ton of steel, and the oxygen blowing lance position is controlled to be 1.5-1.7 m; tapping the smelted molten steel, and obtaining tapped molten steel; adding refining slag into the tapped molten steel for refining, and obtaining low-carbon low-silicon ultralow-sulfur refined molten steel and refining final slag, wherein bottom blowing with 600-800 NL / min of argon is carried out in the initial slagging stage of refining, and bottom blowing with 400-600 NL / min of argon is carried out in the later heating stage of refining, and the heating time is controlled to be shorter than or equal to 15 min; and enabling the content of carbon in the steel to be 0.030%-0.050%, the content of silicon to be less than or equal to 0.050% and the content of sulfur to be less than or equal to 0.0020%.

Description

technical field [0001] The invention relates to the technical field of steelmaking, in particular to a method for producing low-carbon, low-silicon and ultra-low-sulfur steel by adopting an LF single-pass process. Background technique [0002] The low-carbon steel produced by the continuous casting and rolling production line is mainly low-carbon and low-silicon steel. After hot-rolling and cold-rolling, the low-carbon and low-silicon steel has good tensile strength and ductility. It is used in many fields of industry and civil use. The composition of low-carbon and low-silicon steel grades requires a carbon content of 0.010%-0.040%, and a silicon content of ≤0.05%. Due to the continuous casting and rolling production process, in order to ensure the quality of the continuous casting slab and the smooth casting process, the sulfur content of the steel grade is required to be ≤0.0020 %, so the low-carbon steel grades of the continuous casting and rolling production line are l...

AI Technical Summary

Problems solved by technology

This patent is mainly to solve the problems of high rate of change of judgment due to surface quality defects, low component qualification rate and frequent pouring of steel when smelting low-carbon, low-silicon and aluminum-killed steel. The control range of sulfur content in steel is 0.0038%- 0.0060%, and the control range of silicon content is ≤0.04%. The sulfur content of the steel grade in this patent application belongs to the low-sulfur steel grade. Under the premise of low-sulfur steel grade, it is not difficult to control the silicon content, and the silicon content control can be ≤0.05%. ; and the patent application does not clearly propose the level of carbon content control, and only applies to the short-process production of CSP

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