Method for producing high-cleanliness hot-series variety steel at low cost

A high-cleanliness, low-cost technology, applied in the direction of manufacturing converters, etc., can solve the problem of high production cost of clean steel, shorten the production process, avoid uncontrollable inclusions, and improve efficiency.

CN113293253AActive Publication Date: 2021-08-24SHOUGANG JINGTANG IRON & STEEL CO LTD
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2021-08-24

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Abstract

The invention provides a method for producing high-cleanliness hot-series variety steel at low cost, and belongs to the technical field of steelmaking processes. The method comprises the steps that KR desulfurization is carried out on molten iron to acquire desulfurized molten iron, and the sulfur content of the desulfurized molten iron is controlled to be less than or equal to 10 ppm; the desulfurized molten iron is subjected to converter steelmaking, and the sulfur content at the converter steelmaking end point is controlled to be 25-45 ppm; converter tapping is carried out, a desulfurizing agent is added in the tapping process, and the sulfur content of tapping molten steel is controlled to be less than or equal to 20 ppm; the molten steel is subjected to RH refining to acquire refined molten steel, the calcium content in the refined molten steel is controlled to be 8-12 ppm, the oxygen content is controlled to be less than or equal to 12 ppm, and the sulfur content is controlled to be 14-20 ppm; and the refined molten steel is subjected to continuous casting to acquire the high-cleanliness hot-series variety steel produced at low cost. The method can reduce the production cost of the clean steel, and effectively control the content of sulfur and inclusions in the clean steel.
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Description

technical field

[0001] The invention belongs to the technical field of steelmaking technology, and in particular relates to a method for producing high-cleanliness hot grade steel at low cost. Background technique

[0002] In recent years, the domestic iron and steel industry is facing serious overcapacity, and the homogeneous competition of high-end products of advanced steel mills is also becoming more and more serious. For example, some advanced domestic steel mills can produce high-grade pipeline steel, automotive sheets and oriented silicon steel. Therefore, high-efficiency and low-cost production of high-quality steel has become a powerful way for iron and steel enterprises to seek development.

[0003] High-grade pipeline steel is a typical representative of clean steel. At present, the domestic production process is mainly molten iron pretreatment→converter steelmaking→LF refining→RH / VD refining→continuous casting. The existing clean steel production process mainly h...

Examples

Embodiment

[0092] A low-cost production of high-cleanliness thermal grade steel, which is produced by the following method:

[0093] (1) Desulfurization of molten iron: adding fluorine-free desulfurizer to molten iron for KR desulfurization, the amount of said fluorine-free desulfurizer is 8kg / t molten iron, and then carry out slag removal, the liquid surface exposure rate of molten iron reaches 99.5%, obtain desulfurized molten iron, control the The sulfur content of the desulfurized molten iron is ≤10ppm.

[0094] In terms of mass fraction, the chemical composition of the fluorine-free desulfurizer is:

[0095] CaO: 92%, Al 2 o 3 : 3%, SiO 2 : 1%, MgO: 1%, Al: 3%.

[0096] (2) Converter smelting: The desulfurized molten iron is subjected to converter steelmaking, and auxiliary materials are added during the converter smelting process. The amount of the auxiliary materials is 130-140kg / t molten steel. The content is controlled at 25-45ppm.

[0097] Optionally, in terms of mass fra...