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A kind of production method of high-purity rare earth steel

A production method and rare earth technology, which is applied in the field of rare earth addition in the smelting process of CSP process, can solve the problems of unstable rare earth yield and water inlet distillation, and achieve the effects of ensuring the effect of rare earth addition, preventing vortex phenomenon, and ensuring stability

Active Publication Date: 2021-03-16
INNER MONGOLIA UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] The purpose of the present invention is to overcome the shortcomings of the existing rare earth steel production process, which is easy to cause the instability of rare earth yield and the problem of nozzle condensation, and to provide a production method of high-purity rare earth steel

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0040] A 200-ton converter is used to smelt non-oriented silicon steel. The incoming molten iron is pre-desulfurized. The sulfur content is controlled below 0.002%. The slag removal treatment is carried out. The exposed area is 98%, and the temperature of the molten iron is 1320°C. In order to prepare for the addition of rare earth, 6 tons of steel scrap is added to the converter, and the steel scrap is self-produced, and its composition is controlled as follows: C≤0.003%, S≤0.003%, O≤0.003%, [S+O]≤0.005%, Si : 0.15%, Al: 0.30%, Ti≤0.002%, add slag when 1 / 3 of the steel is tapped, and complete the addition at 2 / 3 of the time. A small flow rate of 200NL / min is adopted; after the converter smelting is completed, the tapping time is controlled to be 5 minutes.

[0041] The RH circulation flow rate is 3000NL / min. After 4 minutes of pure degassing time, the circulation flow rate is adjusted to 1200NL / min. At this time, 40kg of pure rare earth neodymium is added, pure degassed for 7...

Embodiment 2

[0047] A 200-ton converter is used to smelt non-oriented silicon steel, and the incoming molten iron is pre-desulfurized, the sulfur content is controlled below 0.002%, and the slag removal treatment is carried out. The exposed area is 99%, and the temperature of the molten iron is 1330°C. In order to prepare for the addition of rare earth, 6 tons of steel scrap is added to the converter, and the steel scrap is self-produced, and its composition is controlled as follows: C≤0.003%, S≤0.003%, O≤0.003%, [S+O]≤0.005%, Si : 0.20%, Al: 0.20%, Ti≤0.002%, add slag when 1 / 3 of the steel is tapped, and complete the addition at 2 / 3 of the time. Use a small flow rate control of 150NL / min; control the tapping time to 7 minutes after the converter smelting is completed.

[0048] The RH circulation flow rate is 3200NL / min. After 5 minutes of pure degassing time, the circulation flow rate is adjusted to 1400NL / min. At this time, a total of 40kg of rare earth cerium and lanthanum is added, 8 m...

Embodiment 3

[0050] A 200-ton converter is used to smelt non-oriented silicon steel. The incoming molten iron is pre-desulfurized. The sulfur content is controlled below 0.002%. Slagging treatment is carried out. The exposed area is 96%, and the temperature of the molten iron is 1325°C. In order to prepare for the addition of rare earth, 6 tons of steel scrap is added to the converter, and the steel scrap is self-produced, and its composition is controlled as follows: C≤0.003%, S≤0.003%, O≤0.003%, [S+O]≤0.005%, Si : 0.18%, Al: 0.26%, Ti≤0.002%, slag is added when tapping 1 / 3 of the steel, and the addition is completed at 2 / 3, and the amount of argon gas is controlled at 1670NL / min when tapping 2 / 3, and the remaining 1 / 3 A small flow rate of 250NL / min is adopted; the tapping time is controlled to be 6 minutes after the converter smelting is completed.

[0051] The RH circulation flow rate is 2800NL / min. After 4 minutes of pure degassing time, the circulation flow rate is adjusted to 1000NL / ...

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Abstract

The invention discloses a high-purity rare-earth steel production method and belongs to the technical field of rare-earth steel production. The high-purity rare-earth steel production method comprisesthe steps of molten iron pretreatment, converter smelting, RH refining and continuous casting, wherein rare earth elements are added in the RH refining process, the initial circulation flow of RH refining is controlled to be 2800-3200 NL / min, and after pure degassing is carried out for 4-5 minutes, the circulation flow is adjusted to be 1000-1400 NL / min, rare earth elements are added at the moment, re-pressing is performed after pure degassing is performed for 7-8 minutes, tranquilizing is performed for 11-12 minutes after re-pressing, and casting is performed. By adopting the method, the rare-earth is added, the rare-earth yield is stabilized to be 20%-25%, a water gap is free of nodulation, and continuous casting of 10 furnaces or above can be realized.

Description

technical field [0001] The invention belongs to the technical field of rare earth steel production, and more specifically relates to a method for adding rare earth to a CSP process smelting process. Background technique [0002] The purity control of molten steel is the most critical step in the preparation of high-quality steel, and the content and size of inclusions are the most important indicators of purity in steel. However, due to the long smelting and production process of iron and steel products and many control links, there are problems of high inclusion content and large inclusion size in steel. It often occurs that the total oxygen content in steel exceeds 15ppm, and the inclusion level is also low. relatively high. Since rare earths in steel have the advantages of purifying molten steel, improving inclusions, and improving performance by alloying, the research on rare earth steels has attracted more and more attention. [0003] However, due to the limitation of...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C22C33/04C21C7/10C21C1/02C21C5/28
CPCC21C1/02C21C5/28C21C7/0006C21C7/10C22C33/04Y02P10/20
Inventor 樊立峰秦美美张志朋何建中华国龙张文博陆斌杨维宇卢晓宇白亮黄娇
Owner INNER MONGOLIA UNIV OF TECH