SU916552A1 - Method for melting steel - Google Patents

Description

The invention relates to metallurgy 1 and can be used in ferrous metallurgy in the smelting of steel.

There is a known method of smelting bearing steel, in which refinos are induced after the oxidation period. it is intensively deoxidized with powdered coke, ferro-oxide and aluminum. During the production period, the metal is intensively mixed with a putty in a ladle and good sulfur removal from steel is ensured. After being released into the ladle, they are deoxidized with lump aluminum in the amount of 0.8 kg / t and poured into SI ingots.

The steel obtained by this method is contaminated with oxide and globular nonmetallic inclusions and cannot surrender by 100% for orders of the highest quality category.

In order to increase the purity of the steppe for globular and oxide inclusions, a method is known in which steel is processed.

four

slag reduced basicity and rinsed with argon in the bucket C2].

Steel produced by this method is contaminated with sulphide non-metallic inclusions, since the slag of reduced basicity does not provide a noticeable removal of sulfur from the metal.

The closest in technical essence and the achieved result to the expected one is the method including charging charge, melting, oxidation, deoxidation of coke and aluminum powders, vacuuming the melt in a ladle with an inert gas purge, alloying the metal with silicon and deoxidizing aluminum ≤ 31.

The disadvantage of this method is the complexity of its implementation, the instability of the results on the contamination of steel with non-metallic inclusions and the poor quality of the metal. Sulfur is poorly removed by treating an unsprayed metal with a spack; the release and evacuation of an undissolved metal increases oxide 916552

Slag potential is low, due to which during evacuation and especially

‘Final aluminum deoxidation is contaminated with oxide nonmetallic inclusions, its quality decreases.

The purpose of the invention is to increase the complexity of the process and improve the quality of the station.

The chain is achieved by the fact that, in a well-known way, including filling the charge, melting, oxidation, deoxidation of coke and aluminum powders, evacuating the melt in a ladle with an inert gas purge, and deoxidizing aluminum in pieces, deoxidizing the steel produce apu-. in an amount of 1.5–3.0 kg / t at the beginning of the recovery period, and doping with silicon is carried out in a furnace before the release of smelting into the ladle.

Deoxidation of steel with aluminum at the end of the oxidation period contributes to its rapid refining from acido-yes. A large amount of aluminum contributes to the good removal of deoxidation products. Amount of aluminum less

1.5 kg / t is ineffective, and more than 3.0 kg / t leads to micro-alloying of steel with apuminium. The sulfur-free deacidification of the slag — hell retains its high basicity and further provides for the removal of sulfur. Alloying with silicon at the end of the recovery period contributes at issue (due to secondary oxidation metal singing ₃₅₎ receivable silicate

inclusions that are good when mixing metal with slag in a ladle are assimilated with a putty. Spac, entangled in the metal during the process of melting, is removed from it when evacuating with purging the melt with argon.

The method reduces the complexity of the process, improves the quality of the steel, since at the same time the steel is cleaned from oxide, globular, sulfide non-metallic inclusions.

For example, Steel ShKh15 is smelted using the method of remelting waste using oxygen in an electric furnace with a capacity of 25 tons. At the end of the oxidation period, the oxidizing shpak is removed, the metal is subsequently deoxidized with lump aluminum in the amount of 1.5-3.0 kg / t and ferromanganese and lime calcining reflux is induced. During the recovery period, slag is deoxidized with coke and aluminum powders. 3-5 minutes before the release of melting, the metal is alloyed with silicon and then released into the ladle. In the ladle, the metal is evacuated at a pressure of 1-10 mm Hg. for 5-10 minutes with stirring of the melt by blowing argon through a porous "insert in the bottom of the ladle.

Steel is poured into bars M & Ss

3.5 tons, rolled on a quality billet with a diameter of 60-100 mm, in which the quality of steel is assessed according to GOST 801-60.

The evaluation results are shown in the table.

Smelting method Amount of aluminum for deoxidation, kg / t Bal according to GOST 801-60 (average score) I melting number “Group in acceptance control,% oxides sulfides globules Famous "M 1.9 1.95 1.66 22.2 Known (lime slag) 1.88 1.93 1.99 69.9 Known (slag reduced basicity) 2.28 1.53 1.55 - Proposed 1.0 1.68 2.15 1.50 71.0 Also 1.5 1.15 1.27 1.14 100.0 3.0 1.49 1.20 1.37 100.0 4.0 1.71 1.18 1.41 85.0

5 916552 6

The proposed method allows single *

temporarily have low values

oxides, sulphides and globules, all steel products meet the requirements

the highest category. five

The economic effect from the introduction of the proposed method of steelmaking is 10,000 rubles.

ten

Claims (3)

Claim A method of steel smelting, including charging of the charge, melting, oxidation, deoxidation of coke and aluminum powders, $ 1 vacuuming the melt in a ladle with inert gas purging, metal doping with silicon and deoxidation with lump aluminum, characterized in that the chain reduces the complexity of the process and increases its qualities; The steel deoxidation is produced in aluminum in the amount of 1.5-3.0 kg / t at the beginning of the recovery period, and the alloying with silicon is carried out in a furnace 1 - with the release of smelting into the ladle. _ Sources of information taken into account in the examination 1. “Metallurg”, 1980, № 4, p. 27. 2. USSR author's certificate No. 461128, cl. C 21 S 7/00, 1975. 3. Bulletin Chermetinformapiya, 1975, No. 15, p. 32-34.