THE FUTURE OF THE ELECTROMETALLURGY

Electro-metallurgy deals with the use of electricity for metal smelting or refining, for alloy manufacturing and for some casting processes. An important branch of electro-metallurgy is the foundry practice. Of great interest are here the melting processes in electric arc furnaces, coreless induction furnaces and cored induction furnace.

Arc furnaces are used for melting high-grade irons intended for special-purpose parts, particularly thin-walled and intricately shaped castings. Electric furnaces offer a number of advantages. They ensure a low melting loss of elements, produce iron with a lower content of impurities, and provide for better working conditions.

Coreless induction furnaces are used for melting iron from a solid metal charge, for preheating the iron and refining it to the analysis. Induction furnaces work on the principle of a transformer: an alternating electromagnetic field induces eddy currents in the metal, so that electric energy converts to heat, whose quantity depends on the resistivity of the charge.

Cored induction furnaces, find effective uses in the making of castings from gray and high-strength irons, and also in the duplex process where a core induction furnace operates in combination with a cupola.

The technology of electroslag casting /ESC/ has great advantages as compared with conventional casting. This technology covers remelting, casting, welding of large-section billets and hard surfacing. The technological process of ESC opens up wide prospects in improving billet production and represents an example of wasteless technology. More about it you will find in the next text.

PRINCIPLES OF ELECTRO-SLAG CASTING

The electroslag casting is a method of producing ingots to a water-cooled metal mould. It is based on the electro-slag process of melting the consumable electrode. A consumable steel electrode is melted by the heat generated in the current-conductive slag when electric current passes through it.

Specific power consumption depends on the slag electric resistance. The higher the resistance, the lower this power consumption is. A high slag resistance contributes to the increase of the melting rate of consumable electrodes and, hence, to a higher efficiency of the ESC process. The molten metal from the fused electrode, permanently immersed into the slag pool, is conveyed into the casting mould without getting in touch with air. The mould executes two functions, i.e. preparing of liquid metal and shaping of ingot.

The ESC as a technology of billet production has great advantages over conventional casting. It provides the possibility of producing the highest-quality metal and ingots of a required shape. Any reaction of molten metal with the material of mould is here completely eliminated. The slag pool serves also as a reliable protection of molten metal against oxidation when being conveyed into the mould. The surface of the casting, solidified in this mould, does not require any subsequent mechanical treatment.

Nowadays the electroslag casting is considered to be one of the most important technological processes determining a progress in machine-building for a durable period of time. New methods of ESC are constantly developed at the B.O.Paton Electric Welding Institute of the Ukrainian Academy of Sciences in collaboration with many industrial enterprises of other countries.

Task 1.	Match the words from column A with their meanings from column B:
A		B
cored induction furnace thin-walled melting loss eddy currents resistivity high-strength coreless induction furnace remelting hard surfacing immerse ingot mould welding		злиток переплав питомий опір наплавлення (поверхневе загартування) високоміцний зварювання вихрові струми ливарна форма занурюватись індукційна канальна піч тонкостінний індукційна тигельна піч угар

Task 2.

Give Ukrainian equivalents to the following words and word combinations:

to deal with, metal smelting, alloy manufacturing, to be of great interest, melting process, particularly, to offer an advantage, to provide conditions, an alternating current, to depend on, the resistivity of the charge, in combination with, as compared, to represent an example of, to open wide prospects, consumption, ESC, water-cooled, power consumption, melting rate, permanently, molten metal, billet production, conventional casting, mechanical treatment, durable period, industrial enterprises, solidify, highest-quality, surface.

Task 3.

Find in the texts English equivalents to the following words and word combinations:

плавлення, рафінування (очищення), процес лиття, галузь металургії, високоякісний, деталі особливого призначення, домішки, заготівка з крупним поперечним розрізом, умови праці, шихта, підігрів, електромагнітне поле, якість, покращувати, електрошлакове лиття, зварка, безвідходна технологія, знаходити застосування, виробництво злитків, залежати від, опір, витратний електрод, окислення, розплавлений метал, виливок складної конфігурації, надійний захист, розробити метод, підприємство, у співробітництві з.

Task 4.	Fill in the correct word from the list below and translate the word combinations. Use the words only once.
		foundry	wasteless	shaped
		electrode	slag	process
		pool	treatment	arc
		billet	touch	power

1. … consumption		5. … practice	9. mechanical …
2. duplex …		6. fused …	10. large-section …
3. current-conductive …		7. intricately… casting	11. … technology
4. to get in …		8. electric … furnace	12. slag …
Task 5.	Give antonyms to the following words:

important, better, low, hard, increase, consumable, heating, melting, many.

Task 6.

Pay attention to the translation of the sentence:

The higher the resistance, the lower this power consumption is.

Think of your own sentences according to this pattern.

Task 7.

Fill in the gaps with the words given bellow. Translate the sentences.

advantages, electricity, processes, melting,

wasteless technology, electroslag casting

1. _____ covers remelting, casting, welding of large-section billets and hard surfacing.

2. Melting _____ in electric arc furnaces, coreless induction furnaces and cored induction furnaces are of great interest.

3. The technological process of ESC represents an example of _____.

4. Electric furnaces offer a number of _____.

5. Electro-metallurgy deals with the use of _____ for metal smelting or refining, for alloy manufacturing and for some casting processes.

6. Arc furnaces are used for _____ high-grade irons.

Task 8.		Make the word combinations matching the words from column A with the words from column B and translate them.
	A		B
	foundry electro-slag effective melting duplex conventional technological		process loss casting practice field use rate

Task 9.	Fill in the table with the missing information.
Furnace or process		Use
Electric arc furnace
		is used for: 1) melting iron from a solid metal charge; 2) preheating the iron and refining it to the analysis
Electroslag casting

Task 10.

Answer the following questions:

1. What does electrometallurgy deal with?

2. What melting processes of electro-metallurgy are of great interest?

3. Do electric arc furnaces have any advantages? What are they?

4. Can you say a few words about coreless induction furnaces?

5. Where do cored induction furnaces find effective uses?

Task 11.	Write about the advantages of electroslag casting as compared with conventional casting.
Task 12.	Translate the following questions into English and answer them:

1. Що включає процес електрошлакового лиття?

2. На чому базується електрошлакове лиття?

3. Чим плавиться споживаний стальний електрод?

4. Від чого залежить споживана потужність у процесі ЕШЛ?

5. Які переваги електрошлакового лиття ви знаєте?

6. Де постійно розробляються нові методи ЕШЛ?