Методическая разработка по английскому языку "Types of welding "
методическая разработка по английскому языку

Types of welding

Цель: изучить новые лексические единицы, научиться выделять основную информацию из текста

Ход работы:

Задание 1. Прочитайте и переведите текст.

Types of welding.

1. As a non-consumable electrodes tungsten or carbon electrodes can be used. In gas-tungsten arc welding a tungsten electrode is used in place of the metal electrode used in shielded metal-arc welding. A chemically inert gas, such as argon, helium, or carbon dioxide is used to shield the metal from oxidation. The heat from the arc formed between the electrode and the metal melts the edges of the metal. Metal for the weld may be added by placing a bare wire in the arc or the point of the weld. This process can be used with nearly all metals and produces a high-quality weld. However, the rate of welding is considerably slower than in other processes.

2. In shielded metal-arc welding, a metallic electrode, which conducts electricity, is coated with flux and connected to a source of electric current. The metal to be welded is connected to the other end of the same source of current. An electric arc is formed by touching the tip of the electrode to the metal and then drawing it away. The intense heat of the arc melts both parts to be welded and the point of the metal electrode, which supplies filler metal for the weld. This process is used mainly for welding steels.

3. In gas-metal welding, a bare electrode is shielded from the air by surrounding it with argon or carbon dioxide gas and sometimes by coating the electrode with flux. The electrode is fed into the electric arc, and melts off in droplets that enter the liquid metal of the weld seam. Most metals can be joined by this process.

4. Submerged-arc welding is similar to gas-metal arc welding, but in this process no gas is used to shield the weld. Instead of that, the arc and tip of the wire are submerged beneath a layer of granular, fusible material that covers the weld seam. This process is also called electro slag welding. It is very efficient but can be used only with steels.

5. Resistance Welding. In resistance welding, heat is obtained from the resistance of metal to the flow of an electric current. Electrodes are clamped on each side of the parts to be welded, the parts are subjected to great pressure, and a heavy current is applied for a short period of time. The point where the two metals touch creates resistance to the flow of current. This resistance causes heat, which melts the metals and creates the weld. Resistance welding is widely employed in many fields of sheet metal or wire manufacturing and is often used for welds made by automatic or semi-automatic machines especially in automobile industry.

Vocabulary

non-consumable electrodes неплавящийся электрод, нерасходуемый

tungsten electrodes  вольфрамовые электроды

carbon - углеродный

laver  слой

weld seam  сварной шов

liquid metal жидкий метал

gas-tungsten — сварка оплавлением вольфрамовым электродом в среде инертного газа

inert — инертный

edge — край

bare — голый

rate — зд. скорость

gas-metal arc — аргонодуговая сварка

considerably — значительно, гораздо

surrounding — окружающий

carbon dioxide— углекислый газ

droplet — капелька

liquid — жидкость, жидкий

beneath — под, ниже, внизу

layer — слой

weld seam — сварной шов

resistance — сопротивление

clamp — зажим, зажимать

sheet— лист

fusible — плавкий

granular — плавкий

semi-automatic — полуавтоматическая

to create — создавать

to submerge— погружать

Задание 2. Перевести на английский язык

1. вольфрамовый электрод 2. инертный газ 3. окисление 4. высококачественный сварочный шов 5. скорость сварки 6. аргон, гелий, углекислый газ 7. жидкий металл 8. слой плавкого материала в виде гранул 9. листовой металл 10. полуавтоматические сварочные станки

Задание 3. Ответьте на вопросы

1. What is the difference between the arc-welding and non-consumable electrode arc welding?

2. What are the disadvantages of the non-consumable electrode arc welding?

3..How is electrode protected from the air in gas-metal arc welding?

4. What is submerged arc welding?

5. What is the principle of resistance welding?

6. Where is semi-automatic welding employed?

Задание 4. Перевести на русский язык

1. In resistance welding, heat is obtained from the resistance of metal to the flow of an electric current.
2. The heat from the arc melts the edges of the metal.

3.    A bare electrode is shielded from the air by surrounding it with argon or carbon dioxide gas.

4. Submerged-arc welding is similar to gas-metal arc welding.
5. Electrodes are clamped on each side of the parts to be welded.
6. Resistance causes heat which melts the metals and creates the weld.