SU1298250A1 - Method for deoxidation of low-carbon steel - Google Patents

Abstract

FIELD OF THE INVENTION The invention relates to ferrous metallurgy, namely to the production of low carbon steels. The purpose of the invention is to reduce the nitrogen content in steel, reduce the recovery of silicon from the lining of the ladle, increase the absorption of aluminum and reduce the consumption of manganese-containing components. Steel deoxidation is carried out in batches of aluminum and manganese-containing components when the steel is poured into the ladle. Mapaniferous components are introduced in the form of carbonate manganese ore in the ratio of aluminum (6-8): 1, with the weight of each subsequent portion of the metering unit being 50-752 from the previous one. The deoxidation method allows to provide a higher quality of steel in terms of the content of non-metallic inclusions, to reduce the nitrogen content by 60%, to increase the degree of aluminum absorption by 2 times and to reduce the consumption of manganese for deoxidation. 1 tab. i (L

Description

The invention relates to ferrous metallurgy, in particular to the production of low carbon steels stabilized by aluminum, and can be used in the melting shops of metallurgical plants,

The purpose of the invention is to reduce the nitrogen content in steel, reduce the recovery of silicon from the lining of the ladle, increase the absorption of aluminum and reduce the consumption of manganese-containing components.

The essence of the invention is to create optimal thermodynamic and kinetic conditions for the reactions of interaction between aluminum and oxygen dissolved in the metal, preventing its side interaction with the lining of the ladle, slag and atmospheric air and the formation, removal and removal of oxygen from the melt. When aluminum is introduced into a non-dilute or weakly deoxidized metal at real temperatures of steelmaking, there is a thermodynamic possibility of its oxidation with oxygen dissolved in the metal, oxygen of atmospheric air, as well as due to the reduction of oxides from the lining of the ladle and oxidized furnace slag that fell during the discharge. At low concentrations of aluminum, first of all, the reaction of its interaction with oxygen dissolved in the metal develops, and non-therapeutic reactions do not proceed. Distributed input of aluminum in the process of filling the ladle with a decrease in the weight of each subsequent batch as the oxidation of the metal in the ladle decreases, ensures its maximum use for deoxidation.

In addition, an additional additive, together with aluminum carbonate manganese ore, improves the kinetic conditions of the interaction of aluminum with metal oxygen, which is achieved with additional mixing of the melt with carbon monoxide resulting from the decomposition of carbonate and the elimination of contact of the melt surface and the stream of metal being drained with atmospheric air 5 which is completely prevented metal saturation with nitrogen.

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The necessity of additive, together with aluminum, namely carbonate manganese ore, is also due to the fact that manganese oxides are additionally introduced into the metal, which contribute to good cleaning of steel from small inclusions of corundum. The purification process is as follows. Manganese oxides, which are formed after the decomposition of carbonate manganese ore, have a low melting point and are in the metal in a liquid state, with intensive stirring of the melt due to hydrodynamic interaction of the carbon monoxide, the processes of combining these inclusions proceed quite intensively. - which leads to the formation of large liquid inclusions of small

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corundum inclusions as a result of metal deoxidation with aluminum at the metal – liquid interface, the inclusion of MpO occurs with less energy than in the bulk of the metal. As a result, large two-layer inclusions of low density are formed in the corundum shell.

The 30 interfacial tension values at the metal-inclusion interface, which are well removed and assimilated by slag.

Aluminum input mode for dilute

35 laziness steel and the additional use of carbonate manganese ore ensures the achievement of the goal. .

The greatest effect is observed, when the ratio of aluminum and carbonate manganese ore in each of the three portions I: (6-8). When this ratio decreases, the ratio is less than 1: 6, the lack of an exact protective effect of carbon monoxide

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 Due to the decrease in volume, the nitrogen content in the steel increases, the aluminum absorption rate decreases due to the interaction with atmospheric oxygen with oxygen, and an increased contamination of the steel with nonmetallic inclusions is also observed. Increasing this ratio to more than 1: 8 is not economically feasible, since it is necessary to release metal with a higher temperature from the furnace due to a strong cooling effect during the decomposition of carbonates, moreover.

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312982,) 0

metal splashes from the coke at the end of its filling are observed.

The reduction in the weight of each subsequent aluminum alloying with carbonate manganese ore is due to the creation of optimal conditions for the deoxidation of the metal, since reducing the portion by less than 25% leads to the formation of zones oversaturated with aluminum (with the introduction of the second, especially the third Ju), the reaction develops. its interaction with atmospheric air, lining of the ladle and slag, which leads to an increased carbon loss of aluminum, an increase in the nitrogen content15 and silicon in steel, as well as increased its contamination with complex oxide inclusions E and aluminum nitride. Reducing the weight of the batch by more than 50% causes an increased oxygen content in the metal after deacidification and high contamination with non-metallic inclusions due to the deterioration of their removal conditions associated with a decrease in the intensity of mixing of the metal in the ladle during production.

Thus, the proposed method is characterized by the regulation of the mode of deoxidation of low-carbon steel 30 by aluminum by using additional material together with a deoxidizer, the ratio of squatted materials by specific consumption and time of entry. 35

For the evaluation, a series of experimental heats was carried out with a change in the proposed parameters both within the specified limits and beyond them.

PRI me R. Experimental melting of wires in the converter shop of the Cherepovets Steel Plant in the industrial production of steel 08yu. After pro-

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The data obtained when conducting research in industrial K conditions showed that the application of the proposed method for calculating low carbon steel with aluminum allows for a higher quality of metal products in terms of the content of nonmetallic inclusions, to reduce the nitrogen content by 60% and silicon in a cold rolled sheet by 4 times and to increase its plastic properties, as well as to increase the degree of aluminum absorption by 2 times and to reduce the consumption of manganese for deoxidation. Output of

metal jumpers in the converter receive

standard low carbon semi-45 or parameter for granite values

a product of practically constant chi-proposed limits leads to

composition,%: C 0.03-0.05; deterioration in quality indicators

MP 0.04-0.09; S 0.015-0.020; Р 0,007- - (table).

6,010.

Deoxidation and alloying of metal 50

Claims (1)

Invention Formula is carried out in a steel-teeming ladle with the following: im image. According to the proposed method, after the steel-bucket bucket is filled with metal, ruminate, respectively, while filling 1/3, 1/2 and 2/3 of the height, aluminum is planted together with carbonate mar five 0 35 ABOUT 0 five with a different ratio of components and the weight of portions and the total consumption of aluminum is 250 kg. Subsequent alloying with aluminum to the required chemical composition and manganese is carried out in the process of argon purging by forcibly introducing aluminum monoliths into the metal in an amount of 750 kg and an additive of manganese MP2 in the amount of 800-900 kg. After the entry of ferroalloys is completed, the metal is additionally flushed with argon through an immersion lance at a rate of 55-60 for 6-8 minutes. According to a known method, 250 kg of primary aluminum of aluminum, together with a slag-forming mixture of lime, fluorspar and magnesium in an amount of 0.5-1.5 tons, are seated at the bottom of the steel-casting ladle. Then, after filling the single-sided pouring ladle, alloying of aluminum; It is carried out using manganese deoxidation and argon treatment in the same way as during the melting process according to the proposed method. The results of the experimental heats for the proposed and known technology are presented in the table. The data obtained when conducting research in industrial K conditions showed that the application of the proposed method for the calculation of low carbon steel with aluminum provides for a higher quality of metal products on the content of nonmetallic inclusions, reduces the nitrogen content by 60% and silicon in the cold rolled sheet 4 times and increases its plastic properties, as well as to increase the degree of assimilation of aluminum by 2 times and reduce the consumption of manganese for deoxidation. Output of Invention Formula 55 The method of deoxidizing steel with a low-carbon diet, including portion feeding of aluminum and manganese-containing components when filling a ladle with steel, is different in that, in order to reduce the nitrogen content in the steel; 512982506 , increasing the degree of assimilation of Ganze ore in relation to alyukova alkmini and reducing the consumption of manganese-containing components, the latter are introduced in the form of carbonate mar- mini (6-8): 1, and the mass of each subsequent portion is 50-75% of the previous one. Compiled by A. Minaev Editor N. Rogulich Tehred A. Kravchuk Proofreader I. Erdeyi Order 861/26 Circulation 550 Subscription VNIIPI USSR State Committee for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5 Production and printing unit, Uzhgorod9 ul. Design, by iminiem (6-8): 1, and the mass of each subsequent portion is 50-75% of the previous one.