Unlock instant, AI-driven research and patent intelligence for your innovation.

A kind of method for restraining low-sulfur steel in LF furnace refining and returning to sulfur

A low-sulfur steel and refining slag technology, applied in the field of suppressing low-sulfur steel refining in LF furnace, low-sulfur steel refining, can solve the problems such as analysis and solution of residue sulfur return in molten steel tank

Active Publication Date: 2022-07-19
武汉钢铁有限公司
View PDF1 Cites 0 Cited by
  • 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 aluminum or steel types that cannot produce high alkalinity reducing slag
The rest of the articles are to reduce the impact of sulfur return by improving the desulfurization efficiency of the LF furnace and rinsing the RH vacuum chamber, without analyzing and solving the sulfur return of the residue in the molten steel tank

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] current technology:

[0027] The smelted steel grade is 82B, silicon deoxidized steel, the sulfur content in the tapped molten steel is 0.021wt%, and the basicity of the slag refined in the LF furnace is 2.68; the time from the end of the molten steel pouring to the turning of the molten steel tank is 13min; After repair, it was put into production of cord steel LX72A. After testing, the sulfur content in tapping molten steel was 0.0083wt%; after acid slag was made by LF furnace, the sulfur was returned to 0.0114wt%, and the sulfur increase was 0.0031wt%.

[0028] this invention:

[0029] 1) The HPB300 steel grade that requires S content not to exceed 0.03wt%; after desulfurization of molten iron, the sulfur content in 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 smelting end point is 0.023wt%;

[0031] 3) Refining in LF furnace:

[0032] First add lime accordin...

Embodiment 2

[0037] current technology:

[0038] The steel grade is GM10Mn, the sulfur content in the tapped molten steel is 0.018wt%, the basicity of the refining slag in the LF furnace is 0.89, the sulfur content in the refining slag is 0.043wt%, and the time from the end of the molten steel pouring to the turning of the molten steel tank is 25min; after hot repair, it was put into production of ultra-low carbon steel DL05. After testing, the sulfur in the tapping molten steel was 0.0042wt%; after heating and refining in the LF furnace, the sulfur was returned to 0.077wt%, and the sulfur increase was 0.0035wt%.

[0039] this invention:

[0040] 1) The GM10Mn steel grade that requires S content not to exceed 0.025wt%; after desulfurization of molten iron, the sulfur content in molten iron after desulfurization is controlled to be 0.014wt%;

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

[0042] 3) Refining in LF fu...

Embodiment 3

[0048] current technology:

[0049] Also in steelmaking, the steel grade is Q235: the sulfur content in the molten iron after desulfurization is 0.035wt%, the sulfur content in the tapping molten steel is 0.039wt%, and the basicity of the refining slag in the LF furnace is 0.96. The time for turning the molten steel tank is 9min; after hot repair, it is put into the production of cord steel LX72A. After testing, the sulfur in the tapping molten steel is 0.0087wt%; after the acid slag is made by the LF furnace, the sulfur is returned to 0.0124wt%, and the sulfur increase is 0.0087wt%. 0.0043 wt%.

[0050] this invention:

[0051] 1) The HPB300 steel grade that requires S content not to exceed 0.030wt%; after desulfurization of molten iron, the sulfur content in molten iron after desulfurization is controlled to be 0.019wt%;

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

[0053] 3) Refining in LF furnac...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

A method for suppressing the sulfur return of low-sulfur steel in LF furnace refining: desulfurizing molten iron requiring S content not exceeding 0.03wt%; converter smelting; LF furnace refining; The time between the beginning of pouring out the refining slag in the tank is not more than 13 minutes; then the smelted low-sulfur molten steel is loaded into the above-mentioned molten steel tank, and the sulfur molten steel is conventionally refined and post-processed in the LF furnace. In the present invention, the steel grades with S content not exceeding 0.03wt% are first smelted in one furnace, and the basicity of the refining slag in the LF furnace is controlled to be less than or equal to 1.2 and the sulfur content in the refining slag is not more than 0.2wt%, so that the sulfur adhering to the molten steel tank is reduced. The content is reduced; after the low-sulfur molten steel to be refined is loaded into the molten steel tank, the sulfur return of the low-sulfur steel refined by LF is stabilized at no more than 0.001wt%, and the rate of correction of the low-sulfur steel is reduced from the original 15.78% to 1.25% , the steel material consumption (hot metal slag removal) is reduced by 2‑3kg / t.

Description

technical field [0001] The invention relates to a smelting method for low-sulfur steel, in particular to a method for inhibiting the return of sulfur from refining of low-sulfur steel in an LF furnace. The invention is suitable for the refining of low-sulfur steel without desulfurization capability in LF furnace. Background technique [0002] The molten steel tank is used to undertake the molten steel and pour the molten steel 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. In the process of changing steel types, the composition between the upper and lower heats will interfere. When the steel grades with desulfurization conditions (cord steel, spring steel, industrial pure iron) are used, an obvious "sulfur return" phenomenon will occur when the molten steel tank is used. [0003] The reason for "sulfur return" in the molten steel tank of the LF furnace: During the refining and...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
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