Shielded Metal Arc

Arc Welding

Arc-welding is the most important welding process for joining steels. It requires a continuous supply of either direct or alternating electrical current. This current is used to create an electric arc, which generates enough heat to melt metal and create a weld.

Arc welding has several advantages over other weld­ing methods. Arc welding is faster because the concen­tration of heat is high. Also, fluxes are not necessary in certain methods of arc welding. The most widely used arc-welding processes are shielded metal arc, gas-tung­sten arc, gas-metal arc, and submerged arc.

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.

Vocabulary:

to join — соединять

pressure welding — сварка давлением

heat welding — сварка нагреванием

instead — вместо, взамен

bolting — скрепление болтами

riveting — клепка

basic — основной

to manufacture — изготовлять

to depend — зависеть от

purpose — цель

available — имеющийся в наличии

equipment — оборудование

source — источник

gas welding — газосварка

arc welding — электродуговая сварка

resistance welding — контактная сварка

laser welding — лазерная сварка

electron-beam welding — электронно-лучевая сварка

flame — пламя

edge — край

simultaneously — одновременно

filler — наполнитель

wire — проволока

rod — прут, стержень

to melt — плавить(ся)

joint — соединение, стык

advantage — преимущество

to require — требовать нуждаться

surface — поверхность

coated — покрытый

flux — флюс

fusible — плавкий

to shield — заслонять, защищать

touching — касание

tip — кончик

General understanding:

1. How can a process of welding be defined?

2. What are the two main groups of processes of welding?

3. How can we join metal parts together?

4. What is welding used for nowadays?

5. Where is welding necessary?

6. What do the welding processes of today include?

7. What are the principles of gas welding?

8. What kinds of welding can be used for joining steels?

9. What does arc welding require? 10. What is the difference between the arc welding and shielded-metal welding?

Exercise 6.1. Find the following words and word combinations in the text:

1. сварка давлением

2. тепловая сварка

3. болтовое (клепаное) соединение

4. процесс сварки

5. зависеть от свойств металлов

6. имеющееся оборудование

7. сварочный электрод

8. плавкий материал

9. дефектный сварной шов

10. непрерывная подача электрического тока

11. электрическая дуга

12. источник электрического тока

Text В: «OTHER TYPES OF WELDING»

Дата добавления: 2014-12-08