Production method of high-cleanliness sulfur-containing and aluminum-containing steel

A technology with high cleanliness and production method, applied in the field of alloy steel, can solve the problems of difficulty in ensuring the secondary oxidation of molten steel with low oxygen content, low level of quality control of molten steel smelting, and inability to meet the requirements of product use, so as to avoid polluting molten steel. The effect of reducing the unevenness of the composition, reducing the labor intensity, and reducing the cost of the production process

Active Publication Date: 2020-06-05
JIANGSU LIHUAI IRON AND STEEL CO LTD +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The cleanliness of this kind of sulfur-containing and aluminum-containing steel also has very high requirements, but most of the sulfur-containing and aluminum-containing steel products produced in China are still in the research of only satisfying the composition requirements and good castability of continuous casting , the quality control level of molten steel smelting is low, especially the cleanliness control of steel, which cannot meet the requirements of product use
[0003] For example, a method for controlling sulfur content in steel published by patent CN201510358287 and a method for smelting sulfur-containing steel published by patent CN201510158044, only about the production method of sulfur retention in molten steel of the electric furnace / converter-LF-(VD) process route, by adding silica Low-alkalinity slag is used to maintain the sulfur content of molten steel, and LF refining feeds sulfur lines and calcium lines, and LF leaves the station and removes slag. It is difficult to ensure low oxygen content in molten steel and avoid secondary oxidation of molten steel, and it is very easy to cause The generation of CaS in the steel blocks the nozzle during continuous casting, so that large-sized, large-particle oxide inclusions and slender sulfides appear in the final steel, making it difficult to ensure the cleanliness of molten steel

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0029] 20CrMnTi, in steel w ([Al]) =0.020%~0.040%, w ([S])=0.020%~0.037%, w ([Si]) =0.20%~0.30%,. It specifically includes the following steps:

[0030] 1) Use high-sulfur molten iron, slag steel and sulfur-containing scrap steel as raw materials, and use top-bottom blowing and double-blowing converters for blowing, and the end point of molten steel is w ([S])=0.035%~0.045%, when the converter is tapping 0t~10t, add 2.0kg / t~3.0kg / t ordinary ferrosilicon alloy for preliminary deoxidation. When the tapping progress is 60%~80%, add 1.3kg / t~1.7kg / t aluminum block for deep deoxidation. 6.0kg / t~7.0kg / t lime and 2.5kg / t~3.0kg / t pre-melted refining slag are added near the end of tapping. Refined to the station w ([Al]) = 0.015% to 0.020%.

[0031] 2) The LF refining process does not add lime, refining slag and other slag materials, and uses aluminum particles and high-purity silicon carbide for diffusion deoxidation on the slag surface and precipitation deoxidation of aluminum ...

Embodiment 2

[0037] F45MnVS, in steel w ([Al]) =0.010%~0.040%, w ([S])=0.035%~0.075%, w ([Si]) =0.30%~0.60%,. It specifically includes the following steps:

[0038] 1) Use high-sulfur molten iron, slag steel and sulfur-containing scrap steel as raw materials, and use top-bottom blowing and double-blowing converters for blowing, and the end point of molten steel is w ([S])=0.035%~0.050%, when the converter is tapping 0t~10t, add 3.5kg / t~5.0kg / t ordinary ferrosilicon alloy for preliminary deoxidation. When the tapping progress is 60%~80%, add 0.9kg / t~1.5kg / t aluminum block for deep deoxidation. 6.0kg / t~7.0kg / t lime and 2.8kg / t~3.5kg / t pre-melted refining slag are added at the end of tapping. Refined to the station w ([Al])=0.010%~0.020%.

[0039] 2) The LF refining process does not add lime, refining slag and other slag materials, and uses aluminum particles and high-purity silicon carbide for diffusion deoxidation on the slag surface and precipitation deoxidation of aluminum particle...

Embodiment 3

[0045] 42CrMo-S, in steel w ([Al]) =0.020%~0.045%, w ([S])=0.015%~0.030%, w ([Si]) =0.17%~0.37%,. It specifically includes the following steps:

[0046] 1) Use high-sulfur molten iron, slag steel and sulfur-containing scrap steel as raw materials, and use top-bottom blowing and double-blowing converters for blowing, and the end point of molten steel is w ([S])=0.030%~0.045%, when the converter is tapping 0t~10t, add 2.5kg / t~3.5kg / t ordinary ferrosilicon alloy for preliminary deoxidation. When the tapping progress is 60%~80%, add 1.1kg / t~1.6kg / t aluminum block for deep deoxidation. 6.0kg / t~7.0kg / t lime and 3.0kg / t~4.0kg / t pre-melted refining slag are added at the end of tapping. Refined to the station w ([Al])=0.020%~0.030%.

[0047] 2) The LF refining process does not add lime, refining slag and other slag materials, and uses aluminum particles and high-purity silicon carbide for diffusion deoxidation on the slag surface and precipitation deoxidation of aluminum particl...

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Abstract

The invention discloses a production method of high-cleanliness sulfur-containing and aluminum-containing steel. The production method comprises the following steps: a top-bottom blowing combined converter is used for blowing, and molten steel is subjected to composite deoxidation, alloying and slagging in the tapping process; heating in the LF refining process, diffusing and deoxidizing of a slagsurface, and precipitating and deoxidizing of molten steel are performed, desulfurizing is not deliberate, the flow of ladle bottom blowing and stirring argon in the whole refining process is controlled, and calcium treatment and soft blowing are performed on the molten steel before the refining is finished; the molten steel is transferred to an RH station, a sulfur line is fed according to the residual sulfur content of the molten steel to a resulfurization target value of the molten steel, vacuum treatment is performed, and micro-calcium treatment denaturation is performed again after the molten steel is broken; and standing and soft blowing are performed on the molten steel; and an arc continuous casting machine performs protective casting. According to the method, the original sulfurcontent of the molten steel is improved, the refining process is not supplemented with slag materials for deliberate desulfurization, only molten steel diffusion and precipitation deoxidation are adopted, weak bottom blowing stirring and calcium treatment are adopted to promote inclusion removal, the sulfur line is fed before the molten steel enters the RH station, so that no component adjustmentis needed after the molten steel RH circulation, secondary pollution of the molten steel is avoided, and high cleanliness control of the molten steel is realized.

Description

technical field [0001] The invention belongs to the technical field of alloy steel and relates to the production of sulfur-containing and aluminum-containing steel, in particular to a production method of high-cleanness sulfur-containing and aluminum-containing steel. Background technique [0002] With the rapid development of my country's vehicle machinery industry, because the MnS inclusions in steel act as a source of stress concentration, cutting off the continuity of the matrix makes cutting easy to break, and has a lubricating effect to reduce tool wear, thereby improving the cutting performance of steel processing , More and more construction machinery steels choose to add a certain amount of sulfur to the steel. The cleanliness of this kind of sulfur-containing and aluminum-containing steel also has very high requirements, but most of the sulfur-containing and aluminum-containing steel products produced in China are still in the research of only satisfying the composi...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C21C5/35C21C7/06C21C7/072C21C7/10
CPCC21C5/35C21C7/0056C21C7/06C21C7/072C21C7/10Y02P10/20
Inventor 印传磊郑力宁翟万里张洪才石可伟林鹏左辉肖波田春阳许正周
Owner JIANGSU LIHUAI IRON AND STEEL CO LTD
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