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Alexandr Polyak

Physical and Metallurgical Faculty

Department of Electrometallurgy

Speciality Ferrous Metals

Research-and-development technology of making of the cored bottom anode of arc steel-smelting stove of direct-current by the method of electro-slag melting

Scientific adviser: , professor Alexander Troyansky

Resume Abstract

Abstract

Content

• Introduction
• 1. Consisting of question
• 2. Making of bottom anode the method of electro-slag melting
• Conclusion
• References

Introduction

Lately in Ukraine and abroad all greater distribution get the arc stoves of direct-current, especially in a machine-building complex.

Steel-smelting stoves which work on a direct current have tokoprovodyaschuyu podinu, or bottom anode, and one (in rare case 2) roof electrode, located in a center a stove. Arc steel-smelting stove of direct-current have high parameters on tekhniko-ekonomicheskim and ecological indexes.

A bottom anode is intended for introduction of electric power to the arc electric stove of direct-current and is an anode. The most widespread bottom anode of the cored type the structural features of which is is examined in this work: use of bimetallic bar which includes steel (overhead) and copper (bottom) parts, more frequent than all electro-slag remelt got a method.

1. Consisting of question

Of world practice exists a few technologies of making of the bimetallic cored, bottom anode are for the arc steel-smelting stoves of direct-current. To such technologies belong method of making of bimetallic bottom anode a way alyumotermicheskoy welding of two parts, also there is a method of making by mechanical connection and technology of making bottom anode by an electro-slag remelt. But these methods possess such failings as costliness and non-standardness of equipment on which is conducted processes.

2. Making of bottom anode the method of electro-slag melting

Taking into account these failings was developed less expense by comparison to a traditional electro-slag remelt, technology of electro-slag melting of copper on a steel purveyance under the layer of slag in heat-insulated graphite crucible with the use of the unexpended graphitized electrode.

The process of melting is carried out in graphite crucible, set on a tricking into a current pallet, with the use of liquid start and subsequent heating of slag bath by an alternating current in a chain a pallet is a bar - overhead graphitized electrode. The serve of copper as a wire is produced with certain speed a trayb-vehicle.

Melting is produced in two stages with the receipt of transitional and basic layers of copper under different slags with the purpose of providing of the high-quality unoxidized surface of contact steel-copper and minimizations of dissolution of iron in a copper, as terms of capacity of bottom anode.

Technology of electro-slag melting, unlike a traditional electro-slag remelt, levels connection a considerable measure between the electric power and speed of melting of bar entered in slag bath, and the same accordingly to decrease the depth of liquid-metal bath. It allowed to support the temperature of slag bath at level, sufficient for melting of given copper charge with the overheat of fusion of copper no more than 20 °C. Technology provides for, with the purpose of minimization of diffusion of iron in coppers, management consolidation by means of the periodic «freezing» of melting layers of metal with the receipt of high-quality narrow transitional area.

At melting the use of gumboil of composition is expedient:

1th. Na₂B₄O₇- basis

2th. Na₃AlF₆– basis

The chosen gumboil is provided by the reliable removing of oxides from a steel purveyance and, as a result, high adgeziyu of copper to steel. In 30 mm from a joint maintenance of iron is well-to-do in a copper at the level of chemical composition of copper of M2-M1.

The table of contents of iron in copper part of bottom anode does not exceed 0,1%, while at traditional technology of receipt of the bimetallic cored bottom anode the method of electro-slag remelt this size arrives at 4% and this be very important because maintenance of iron in copper part considerably worsens conductivity and heat conductivity.

Conclusion

During the leadthrough of this advanced study was developed more perfect and less expense technology of making bottom anode. This technology allows to make high-quality bottom anode with a minimum transitional area and maintenance of iron in copper part of bottom anode no more than 0,1%, that allows to save the high indexes of conductivity and heat conductivity.

References

1. Калмыков В.А., Карасев В.П. Электрометаллургия стали: Учеб. Пособие. СПб: Изд-во СПбГТУ, 1999. 292 с.
2. Применение ЭШП по двухконтурной схеме для получения сталемедных заготовок анодов дуговых печей постоянного тока / В. А. Зайцев [и др. ] // Современная электрометаллургия. - 2011. - N 2. - С. 3-7
3. Зайцев, В. А. Подовые электроды дуговых печей постоянного тока / В. А. Зайцев, Л. Б. Медовар // Современная электрометаллургия. - 2009. - N 2. - С. 3-8
4. Разработка подового электрода дуговой печи постоянного тока и технологии его изготовления П.И. Тищенко, Н.Б. Дунь, А.П.Тищенко (фирма «РОУД»), А.Д. Рябцев, С.Н. Тимошенко (ДонНТУ)
5. Электрошлаковая наплавка меди и ее спла¬вов на сталь, Лычко И. И., УкрНИИНТИ, К., 1969.
6. http://masters.donntu.ru/2008/fizmet/polyak/index.htm