Casting Terminology

The casting starts with the construction of a pattern, an approximate duplicate of the final casting. The moulding material is then packed around the pattern, and the pattern is removed to produce a mould cavity. The flask is the box that contains the moulding aggregate. In a two-part mould, the cope is the top half of the pattern, flask, mould or core. The drag is the bottom half of any of these features. A core is a sand shape that is inserted into the mould to produce internal features on a casting, such as holes or passages for water cooling. A core print is the region added to the pattern, core, or mould that is used to locate and support the core within the mould. The mould material and the core then combine to form the mould cavity, the void into which the molten metal will be poured and solidified to produce the desired casting. A riser is an extra void created in the mould that will be filled with molten metal. It provides a reservoir of molten metal that can flow into the mould cavity to compensate for any material shrinkage that occurs during solidification. Any shrinkage voids should then be in the riser and not in the final casting.

The gating system is the network of channels used to deliver the molten metal from outside the mould into the mould cavity. The pouring cup is the portion of the gating system that initially receives the molten metal from the pouring vessel and controls its delivery to the rest of the mould. From the pouring cup, the metal travels down the sprue (the vertical portion of the gating system), then along horizontal channels (called runners), and finally through controlled entrances, or gates, into the mould cavity.

The parting line or parting surface is the interface that separates the cope and drag halves of the mould, flask, or pattern, and the halves of a core during some core-making processes. The draft is the taper on a pattern or casting that permits it to be withdrawn from the mould. The mould or die used to produce casting cores is known as a core box. Finally, the term casting is used to describe both the process and the product when molten metal is poured and solidified in a mould.

Words to be memorized:

flask	опока
cope	верхня опока
core	ливарний стрижень
core print	стрижневий знак
die	металева форма, кокіль, кристалізатор
draft	формувальний нахил
drag	нижня частина опоки
gate	ливник
insert	вставляти
pouring cup	наливна лунка
riser	стояк, отвір у верхній частині виливниці
runners	ливники, ливникові ходи
sprue	вертикальний ливник
taper	конус

Task 6. Continue the following:

1. Solidification process, the solid physics …

2. To finish the casting process, the finish, to finish the work …

3. The pouring method, to pour …

4. The mould cavity, to fill the cavity …

Task 7. Open the brackets:

1. The molten material (to consider) to be poured into a cavity or mould for achieving the proper shape during solidification.

2. Casting (to know) to be the best of the most important of the manufacturing processes.

3. (To achieve) the best results and economy the designer must understand the various options and use the most appropriate process in the most efficient manner.

4. (to use) for repeated castings, a material can withstand each casting process.

5. The designers prefer the more economical expendable moulds (to use) for production of smaller quantities.

6. Provision must be (to make) in a proper way that the mould will not cause too much restraint to the shrinkage.

7. Six basic factors (to involve) in casting process.

8. A pouring technique must be devised (to introduce) the molten metal into the mould.

9. Extraneous material (to attach) where the metal entered the cavity, excesses at mould parting lines and mould material (to attach) to the casting surface must be removed.

Task 8.

Match the terms from column A with their definition from column B and translate the sentences:

A

B

1.The flask 2. The drag 3. A core 4. A core print 5. A riser 6. The gating system 7. The pouring cup 8. The runners 9. The sprue

a. is the bottom half of flask. b. is a sand shape that is inserted into the mould to produce internal features on a casting, such as holes or passages for water cooling. c. is the vertical portion of the gating system. d. is the network of channels used to deliver the molten metal from outside the mould into the mould cavity e. is the box that contains the moulding aggregate. f. is the region added to the pattern, core, or mould that is used to locate and support the core within the mould. g. are the horizontal channels of the gating system. h. is the portion of the gating system that initially receives the molten metal from the pouring vessel. i. is an extra void created in the mould that will be filled with molten metal.

Task 9. Answer the following questions:

1. How many factors are involved in casting process? What are they?

2. What are the demands for mould cavity?

3. What types of moulds do you know?

4. How does the casting start?

5. What is a flask?

6. What is used to produce internal features of a casting?

7. What is a riser?

8. What delivers the molten metal from outside the mould into the mould?

Task 10. Speak on the following:

1. Casting is one of the most important manufacturing processes. (Think about advantages of the casting.)

2. List the main factors of the casting process. (Note the main features.)

3. Give a detailed description of the gating system. (Use the terminology from the text: network of channels, to deliver, the mould cavity, the pouring cup, the pouring vessel, runners, gates, etc.)

UNIT 6

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
1. cored induction furnace 2. thin-walled 3. melting loss 4. eddy currents 5. resistivity 6. high-strength 7. coreless induction furnace 8. remelting 9. hard surfacing 10. immerse 11. ingot 12. mould 13. welding	a) злиток b) переплав c) питомий опір d) поверхневе загартування e) високоміцний f) зварювання g) вихрові струми h) ливарна форма i) занурюватись j) індукційна канальна піч k) тонкостінний l) індукційна тигельна піч m) 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.

a) foundry	e) wasteless	i) shaped
b) electrode	f) slag	j) process
c) pool	g) treatment	k) arc
d) billet	h) touch	l) 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.

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