Method for inhibiting low-sulfur steel from being subjected to refinement and resulfurization in LF furnace

A technology for low-sulfur steel and refining slag, which is applied in the refining of low-sulfur steel, restrains the sulfur-returning of low-sulfur steel in the field of LF furnace refining, and can solve the problems of analysis and solution of sulfur-returning of residues in molten steel tanks.

Active Publication Date: 2021-11-05
武汉钢铁有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This method makes reducing slag desulfurization by adding aluminum (0.026wt%), so that the amount of desulfurization ≈ the amount of sulfur increase, so as to achieve the effect of no resulfurization, but the requirements for steel types have certain limitations, such as adding This method cannot be used for aluminu

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] current technology:

[0027] The steel type smelted is 82B, silicon deoxidized steel, the sulfur content in the molten steel for tapping is 0.021wt%, and the basicity of the refining slag in the LF furnace is 2.68; it takes 13 minutes from the end of pouring the molten steel to turning over the ladle; After the repair, it was put into the production of cord steel LX72A. After testing, the sulfur in the steel water was 0.0083wt%; after the acid slag was produced by the LF furnace, the sulfur was returned to 0.0114wt%, and the sulfur was increased to 0.0031wt%.

[0028] this invention:

[0029] 1) The HPB300 steel type that requires the S content to be no more than 0.03wt%; through desulfurization of molten iron, the sulfur content in the molten iron after desulfurization is controlled to be 0.018wt%;

[0030] 2) Carry out converter smelting, and the sulfur content of molten steel at the end of smelting is 0.023wt%;

[0031] 3) Refining in LF furnace:

[0032] First ad...

Embodiment 2

[0037] current technology:

[0038] The steel type is GM10Mn, the sulfur content in the molten steel is 0.018wt%, the basicity of the refining slag in the LF furnace is 0.89, and the sulfur content in the refining slag is 0.043wt%. 25min; put into production of ultra-low carbon steel DL05 after hot repair, after testing: the sulfur in the tapping steel is 0.0042wt%; after heating and refining in the LF furnace, the sulfur is returned to 0.077wt%, and the sulfur is increased to 0.0035wt%.

[0039] this invention:

[0040] 1) The GM10Mn steel type that requires the S content to be no more than 0.025wt%; through desulfurization of molten iron, the sulfur content in the molten iron after desulfurization is controlled to 0.014wt%;

[0041] 2) Carry out converter smelting, the sulfur content of molten steel at the end of smelting is 0.019wt%;

[0042] 3) Refining in LF furnace:

[0043]First add lime according to 6.7Kg / ton of steel, and then add quartz sand according to 4.9Kg / ton...

Embodiment 3

[0048] current technology:

[0049] Also in steelmaking, the steel type is Q235: the sulfur content in the molten iron after desulfurization is 0.035wt%, the sulfur content in the tapped molten steel is 0.039wt%, and the basicity of the refining slag in the LF furnace is 0.96, which is from the end of molten steel pouring to It takes 9 minutes to turn over the steel tank; after hot repair, it is put into the production of cord steel LX72A. After testing, the sulfur in the tapping steel water is 0.0087wt%; 0.0043 wt%.

[0050] this invention:

[0051] 1) The HPB300 steel type that requires the S content to be no more than 0.030wt%; through desulfurization of molten iron, the sulfur content in the molten iron after desulfurization is controlled to be 0.019wt%;

[0052] 2) Carry out converter smelting, the sulfur content of molten steel at the end of smelting is 0.022wt%;

[0053] 3) Refining in LF furnace:

[0054] First add lime according to 5.2Kg / ton of steel, and then add...

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PUM

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Abstract

The invention discloses a method for inhibiting low-sulfur steel from being subjected to refinement and resulfurization in an LF furnace. The method comprises the following steps of, desulfurizing molten iron of a steel grade with S content not more than 0.03 wt%; smelting in a converter; refining in an LF furnace; carrying out pouring and subsequent procedures, wherein the time from the end of molten steel pouring to the beginning of pouring refining slag out of a molten steel tank is controlled to be not more than 13 min; and Then loading the smelted low-sulfur molten steel into the molten steel tank, and carrying out conventional refining and subsequent procedures on the sulfur molten steel in the LF furnace. According to the method, by smelting steel with S content not more than 0.03 wt% in one furnace and controlling the alkalinity of the refining slag in the LF furnace to be less than or equal to 1.2 and the sulfur content in the refining slag to be not more than 0.2 wt%, so that the content of sulfur attached in the molten steel tank is reduced; and after the low-sulfur molten steel to be refined is filled into the molten steel tank, the resulfurization of the low-sulfur steel subjected to LF refining is stabilized to be less than or equal to 0.001 wt%, the judgment-changing rate of the low-sulfur steel is reduced to 1.25% from the original 15.78%, and steel material consumption (molten iron slagging-off) is reduced by 2-3 kg/t.

Description

technical field [0001] The invention relates to a method for smelting low-sulfur steel, in particular to a method for suppressing sulfur return of low-sulfur steel during refining in an LF furnace. The invention is suitable for refining low-sulfur steel which does not have desulfurization ability in LF furnace. Background technique [0002] The molten steel tank is used for receiving molten steel and performing pouring operations during the steelmaking process. The molten steel tank is a large tool in the steelmaking process, and it is unlikely to be replaced at any time. During the process of switching steel types, the components between the upper and lower furnaces will interfere. When steel grades with desulfurization conditions (cord steel, spring steel, industrial pure iron) are used, the phenomenon of "resulfurization" will obviously occur when using the molten steel tank, and the sulfur content will increase by 0.0015-0.005wt%, which may lead to unqualified component...

Claims

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Application Information

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IPC IPC(8): C21C7/064C21C5/28C21C7/00
CPCC21C7/064C21C5/28C21C7/0087C21C7/0037C21C2007/0093
Inventor 廖扬标王光进潘艳华孟磊王彦林吴义强段光豪刘东清韩元庭
Owner 武汉钢铁有限公司
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