A high-efficiency production process for high-standard bearing steel

A standard bearing and production process technology, applied in the direction of manufacturing converters, etc., can solve the problems of easy transformation of inclusions, large amount of ferrochrome added, and reduced production efficiency of bearing steel, achieving significant economic effects, improving production efficiency, and avoiding coiling. The effect of the slag problem

Active Publication Date: 2021-04-30
ZENITH STEEL GROUP CORP +1
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

②Although aluminum deoxidation is used in the tapping process, the inclusions after tapping are solid Al with high removal efficiency. 2 o 3 , but during the LF treatment of molten steel, due to operations such as slag making and submerged arc heating, the slag steel reacts, making Al 2 o 3 Inclusions are easily transformed into calcium-aluminate, which is not conducive to subsequent control. Even if vacuum treatment is performed, it cannot be removed well, thus increasing the probability of B-type or Ds-type calcium-aluminate inclusions exceeding the standard in steel.
[0005] Although the use of LF refining will bring many problems, for bearing steel with high alloy content, due to the limited control of the tapping temperature of the converter, and the large amount of ferrochrome added during the tapping process, the temperature of the molten steel after tapping is low, and the molten steel can only reach LF furnace is used for heating and alloying treatment. At present, iron and steel enterprises including Xingcheng Special Steel adopt this production process. This method not only reduces the production efficiency of bearing steel, but also does not improve the quality of steel.

Method used

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  • A high-efficiency production process for high-standard bearing steel
  • A high-efficiency production process for high-standard bearing steel
  • A high-efficiency production process for high-standard bearing steel

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Experimental program
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Effect test

Embodiment 1

[0022] Finished steel composition C: 0.96%, Si: 0.22%, Mn: 0.35%, P: 0.011%, S: 0.007%, Al: 0.015%, Cr: 1.47%.

[0023]The converter adopts double slag process, the raw materials are molten iron and scrap steel, and the ratio of scrap steel is 15%. Converter blowing 5min to carry out slagging operation, converter final slag basicity is 3.2, FeO content is 16%, converter end point C content is 0.05%, end point P content is 0.011%, end point S is controlled at 0.007%, converter tapping temperature is 1668°C. Add 140kg of aluminum cake during the tapping process, then add 250kg of preheated low-titanium and low-aluminum ferrosilicon, 400kg of high-carbon ferromanganese, 2800kg of low-titanium and high-carbon ferrochrome, then add 1000kg of low-nitrogen carburizer, and add 600kg of lime and 100kg fluorite for slag making. The temperature of the molten steel after tapping from the converter is 1574°C.

[0024] The composition of the slag entering the RH station is shown in Table...

Embodiment 2

[0033] Finished steel composition C: 0.97%, Si: 0.25%, Mn: 0.32%, P: 0.013%, S: 0.008%, Al: 0.018%, Cr: 1.42%.

[0034] The converter adopts double slag process, the raw materials are molten iron and scrap steel, and the ratio of scrap steel is 15%. Converter blowing 5min to carry out slagging operation, converter final slag basicity is 3.5, FeO content is 14%, converter end point C content is 0.07%, end point P content is 0.013%, end point S is controlled at 0.008%, converter tapping temperature is 1689°C. Add 140kg of aluminum cake during the tapping process, then add 250kg of preheated low-titanium and low-aluminum ferrosilicon, 400kg of high-carbon ferromanganese, 2800kg of low-titanium and high-carbon ferrochrome, then add 1000kg of low-nitrogen carburizer, and add 600kg of lime and 100kg fluorite for slag making. The temperature of the molten steel after tapping from the converter is 1583°C.

[0035] The composition of the slag entering the RH station is shown in Tabl...

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Abstract

The invention belongs to the technical field of steelmaking technology, and relates to a high-efficiency production technology of high-standard bearing steel, which adopts the "BOF-RH-CC" process route. The alloy is melted by the alloy melting furnace, which cleverly solves the problem of large temperature drop of the molten steel due to the addition of a large amount of alloys such as ferrochrome during the tapping process. After tapping, the molten steel can be directly vacuumed at the RH station. By canceling the LF refining furnace, the improvement of production efficiency, avoiding the problem of slag entrainment in refining slag, and at the same time avoiding the reaction of slag steel caused by the submerged arc heating process of LF slag making, making Al 2 o 3 The inclusions are transformed into calcium aluminates that are not conducive to subsequent control, and the inclusions can be controlled throughout the process to be solid Al with high removal efficiency 2 o 3 , after RH vacuum, Al 2 o 3 The inclusions are efficiently removed, and the total oxygen in the molten steel is controlled to 3.0-4.5ppm. At the same time, because the Al in the steel 2 o 3 Inclusion control, the excessive ratio of B-type and Ds-type calcium-aluminate inclusions in steel is greatly reduced.

Description

technical field [0001] The invention belongs to the technical field of steelmaking technology, and in particular relates to a high-efficiency production technology of high-standard bearing steel. Background technique [0002] Bearings are required to have high resistance to contact fatigue due to high alternating loads during service. The research results show that the lower the total oxygen in the steel and the fewer the number of large-size inclusions in the steel, the higher the fatigue life of the steel. Therefore, bearing steel should not only pursue low total oxygen, but also strictly control the large-size inclusions in the steel. [0003] At present, domestic bearing steel production processes are roughly divided into two categories, one is produced by die casting, such as Chinese patent application number CN201611079071.0 "Smelting method of high-purity bearing steel" and Chinese patent application number CN201710622627.4" A method for manufacturing carburized bear...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C22C38/02C22C38/04C22C38/06C22C38/18C22C33/06C21C5/36C21C7/06C21C7/10C21C7/00
CPCC21C5/36C21C7/0006C21C7/0025C21C7/06C21C7/10C22C33/06C22C38/02C22C38/04C22C38/06C22C38/18
Inventor 徐建飞王郢王昆鹏沈艳管挺
Owner ZENITH STEEL GROUP CORP
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