Text 1 forging and forging operations

1. All machines are built up of parts made of different materials by various manufacturing processes. Some parts are cast from metals; some are forged, while others are produced by machining.

2. Forging is an extremely important process in the machine-building industry. No machine, whether simple or complicated, can be built without the use of forgings.

The enormous importance of forging is shown by the act that nearly every machine shop has a forge division, and every machine-building plant – a forge shop.

3. Forged products are particularly widespread in the tractor, automobile, agricultural machinery, ship-building, locomotive building and in many other industries. For instance, in the railway car building industry up to 70 per cent of all the parts which go to make up a car are forgings. Not only parts of machines, but also many tools are manufactured by forging.

4. Technological process “forging” is one of the most important in the plastic working of metals. Forging enhances the mechanical properties of metals and improves their structure and quality. After forging any metal becomes stronger. For this reason, machine parts which are subjected to heavy duty are generally made of forgings. Moreover, the time required for the manufacture of a part or a tool is very often reduced by forging, much less metal is consumed in its production and, consequently, the cost of any forged part is reduced.

5. Forging operations can be hand and machine ones. Hand forging is carried out on anvils with the help of hand forging tools. Machine forging is done under forge hammer blows or on presses. Forgings which have to undergo subsequent machining are called blanks. Those which do not require any further machining are known as finished forgings.

6. One and the same part can be forged by different methods and on different forging machines. However, it is always necessary to select the most suitable method for forging which will: a) ensure a high-quality forging; b) ensure high productivity; c) entail the minimum consumption of physical energy and metal; d) ensure complete safety during forging.

7. The process of making a part by forging consists of several separate operations, the chief of which are: selecting and preparing the stock for forging; heating the metal; forging the stock to the requisite shape and dimensions.

8. The hammer forging method entails many forging operations: cutting, upsetting, bending, drawing, and others. The production of any kind of forging necessitates the employment of some or all of operations in different sequence. Sometimes one, two or three operations have to be repeated several times.

9. Forgings are superior or equal to parts produced by other metal working methods in their adaptability to various other manufacturing processes such as heat treatment, welding, machining, mechanical joining, etc.

Comprehension assignments

1. Find in the text English equivalents to the following Ukrainian words and word combinations:

• вироблений механічною обробкою;

• машинобудівна промисловість;

• простий чи складний механізм;

• побудований без використання кування;

• майстерня-кузня;

• особливо поширений;

• багато інструментів виготовляється куванням;

• збільшувати механічні властивості металів;

• покращувати структуру та якість;

• вартість деталі, що викували, зменшується;

• здійснюється на ковадлах;

• підлягати подальшій механічній обробці;

• вимагати;

• обирати найбільш вдалий спосіб кування;

• гарантувати висококваліфіковане кування.