Method for producing ultralow-sulfur steel by using LF and VD duplex technology

A dual process, ultra-low sulfur technology, applied in the field of steelmaking, can solve the problems of high smelting cost, complex process route, and great impact on continuous operation.

Active Publication Date: 2021-06-15
SHOUGANG CORPORATION
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The patented process route is relatively complicated, using two LF furnace refining + two VD vacuum treatment proces

Method used

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  • Method for producing ultralow-sulfur steel by using LF and VD duplex technology
  • Method for producing ultralow-sulfur steel by using LF and VD duplex technology
  • Method for producing ultralow-sulfur steel by using LF and VD duplex technology

Examples

Experimental program
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Example Embodiment

[0060] Example 1

[0061] Steel X60ms, the target finished sulfur content is less than 0.0010%, the process route adopted: Kr desulfurization pretreatment - converter-LF furnace refined - VD refining - continuous casting.

[0062] Step S1, the iron water is carried out in Kr desulfurization, and the stirring time is controlled at 10 min, and the slag pretreatment (95% of the slag, the splashing surface rate is 95%), and the pretreatment of S = 0.0015%;

[0063] Step S2, the converter smelting: The sulfur content of the waste steel is 0.0050% by low sulfur, and the amount of the sulfur content of the excipient is 0.0040%, and the stirring time is controlled in 12 min, and the S content is 0.0060% smelting steel liquid; The steel is used to use aluminum, and the addition is 2.5 kg / t steel; the end of the steel packet is deoxygenated to the steel packet surface, and the addition amount is 0.5 kg / t steel;

[0064] Step S3, LF furnace refining desulfurization: control slag oxidatio...

Example Embodiment

[0067] Example 2

[0068] The steel type Q345R-HIC, the target finished sulfur content is less than 0.0010%, the process route adopted is: Kr desulfurization pretreatment - converter - LF furnace refining - refinement - continuous casting.

[0069] Step S1, the iron water is carried out in Kr desulfurization, and the stirring time is controlled at 15 min, and the slag pretreatment (98% of the slag ", obtaining S = 0.001% pretreatment iron water;

[0070] Step S2, the converter smelting: The sulfur content of the waste steel is 0.0050%, and the amount of the sulfur content of the excipient is 0.0030%, and the smelting mixing time is controlled at 15 min, and the S content is 0.0050% smelting steel liquid; The steel is used to use aluminum deoxidation. The addition is 1.0 kg / t steel; the end of the steel bag is added to the steel puces, and the graft is deoxidized, and 0.3 kg / t steel;

[0071] Step S3, LF furnace refining desulfurization: control slag oxidation resistance, final...

Example Embodiment

[0074] Example 3

[0075] The steel species A516GR.60-HIC, the target finished sulfur content is less than 0.0010%, the process route adopted is: Kr desulfurization pretreatment - converter - LF furnace refining - VD refining - continuous casting.

[0076] The steel type Q345R-HIC, the target finished sulfur content is less than 0.0010%, and the process route adopted is: Kr desulfurization pretreatment - converter - LF furnace refined - VD refining - continuous casting.

[0077] Step S1, the iron water is carried out to Kr desulfurization pretreatment, and the stirring time is controlled at 12 min, and the slag pretreatment (96% of the slag shift surface rate) is obtained, and the pretreatment of S = 0.0015%;

[0078]Step S2, the converter smelting: The sulfur content of the waste steel is 0.0040% by low sulfur, and the sulfur content of the excipient is 0.0040%, and the stirring time in the smelter is controlled at 13 min, and the S content is 0.0045% smelting steel liquid; The s...

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Abstract

The invention discloses a method for producing ultralow-sulfur steel by using an LF and VD duplex technology. The method comprises the following steps: 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 to obtain smelted molten steel; carrying out tapping of the smelting molten steel to obtain the tapped molten steel; adding refining slag into the tapped molten steel for LF furnace refining to obtain refined molten steel and first refined final slag; controlling the first refining final slag, wherein W (FeO + MnO) is less than or equal to 1.5%, and the binary alkalinity R = CaO/SiO2 = 5.0-8.0; and subjecting he refined molten steel to VD vacuum refining to obtain ultralow-sulfur molten steel and second refined final slag, wherein the vacuum treatment time is 12-20 min, the bottom blowing flow of a steel ladle is 50-150 NL/min, and the vacuum degree is controlled to be less than or equal to 100 Pa; Stable control of ultralow sulfur less than or equal to 0.0010% is achieved by using the LF and VD duplex technology.

Description

technical field [0001] The invention relates to the technical field of steelmaking, in particular to a method for producing ultra-low sulfur steel by adopting LF+VD double process. Background technique [0002] With the increasing demand for high-grade steel grades, the quality requirements for steel are becoming more and more stringent, and sulfur is a harmful element in most steels, which can cause hot embrittlement of steel, and can also damage the steel by forming sulfide inclusions. The mechanical properties are adversely affected, and the sulfur content in the steel is required to be as low as possible, especially for steels that have special inspection requirements for HIC and SSCC, such as hydrogen-induced cracking-resistant pipeline steel and hydrogen-induced cracking-resistant container steel. Generally, the sulfur content is required to be less than 0.0010 %, therefore, whether the stable control of ultra-low sulfur content in steel has become the key to the produ...

Claims

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Application Information

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IPC IPC(8): C21C7/06C21C7/076C21C7/064C21C7/10C21C1/02
CPCC21C7/06C21C7/076C21C7/064C21C7/10C21C1/02Y02P10/20
Inventor 李战军刘金刚初仁生郝宁朱志远朱国森马长文季晨曦高宠光闫占辉谢翠红杨荣光
Owner SHOUGANG CORPORATION
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