1) What technology and welding processes do the nuclear power plants and spaceships require?

2) What welding process was the basic method just a few years ago?

3) What methods of welding do our scientific pay great attention to?

4) Where are the scientific and technical aspects of welding studied?

5)What welding methods are used for joining refractory metals? 

VOCABULARY:

1) welding - сварка

arc - дуговая сварка

forge - кузнечная сварка

resistance - контактная сварка

2) add - добавлять

3) flame – пламя

Exercise 1. Answer the following questions. Use the background knowledge.

1. Have you got any information about welding?

2. Can you name types of welding?

3. How was welding being devoloped historically?

4. What type of welding was the first?

5. What type of welding did appear then?

Exercise 2.Give Russian equivalents to the following words without dictionary:

Text 2. Welding

Welding is a fabrication or sculptural process that joins materials, usually metals or thermoplastics, by causing coalescence. This is often done by melting the workpieces and adding a filler material to form a pool of molten material (the weld pool) that cools to become a strong joint, with pressure sometimes used in conjunction with heat, or by itself, to produce the weld. This is in contrast with and brazing, which involve melting a lower-melting-point material between the workpieces to form a bond between them, without melting the workpieces.

Many different energy sources can be used for welding, including a gas , an electric arc, a laser, an electron beam, friction, and ultrasound. While often an industrial process, welding can be done in many different environments, including open air, under water and in outer space. Regardless of location, however, welding remains dangerous, and precautions are taken to avoid burns, electric shock, eye damage, poisonous fumes, and overexposure to ultraviolet light.

Until the end of the 19th century, the only welding process was forge welding, which blacksmiths had used for centuries to join iron and steel by heating and hammering them. Arc welding and oxyfuel welding were among the first processes to develop late in the century, and resistance welding followed soon after. Welding technology advanced quickly during the early 20th century as World War I and World War II drove the demand for reliable and inexpensive joining methods. Following the wars, several modern welding techniques were developed, including manual methods like shielded metal arc welding, now one of the most popular welding methods, as well as semi-automatic and automatic processes such as gas metal arc welding, submerged arc welding, flux-cored arc welding and electroslag welding. Developments continued with the invention of laser beam welding and electron beam welding in the latter half of the century. Today, the science continues to advance. Robot welding is becoming more commonplace in industrial settings, and researchers continue to develop new welding methods and gain greater understanding of weld quality and properties.

Vocabulary: