Text A
Welding
Welding is a way of heating pieces of metal using electricity or a flame so that they melt and stick together. There are many kinds of welding, includingarc welding, resistance welding and gas welding. The most common type is arc welding. Anyone who is near arc welding needs to wear a special helmet or goggles because the arc is so bright. Looking at the arc will hurt your eyes, maybe forever. It is also important to cover all your skin because it can give you something like a sunburn. Hot sparks from the weld can burn any skin that is showing. One kind of welding that does not use an arc is Oxy-fuel welding (OFW), sometimes called gas welding. OFW uses a flame. Any kind of welding that uses an electric arc is a kind of arc welding. There are different kinds of arc welding too— shielded metal arc welding (SMAW) is a common type. Sometimes SMAW is called stick welding. Another common one is gas metal arc welding (GMAW). Another type of arc welding that is less common isgas tungsten arc welding (also known as tungsten inert gas welding or TIG welding). Before there were many kinds of arc welding, SMAW was called just 'arc welding'. Sometimes it is still called that today, but it's better to call it by it's real name instead. Arc welding heats metals by making an electric arc between the piece of metal and something called an electrode. An electrode is the part of the welder that the arc touches.
All types of welding require that the hot metal have protection. If it didn't, things on the metal or things in the air could cause problems in the weld. Things on the metal that could cause problems might be rust, grease, or dirt. Oxygen in the air will cause big problems in a weld. There are two main ways to shield an arc welding, they are flux and shielding gas.
Flux can be made of many things, but it can be a solid or a paste. During welding, the flux will melt and some of it will evaporate. It makes a gas pocket. It is much easier for an electric arc to flow in this gas pocket than through normal air. This pocket of gas prevents air, especially oxygen, from getting into the weld. The liquid flux will cool down and turn into a solid again. It helps to protect the weld while it cools down. One type of welding that uses flux is shielded metal arc welding. Shielded metal arc welding is used to build things, like buildings or pipes. It is also used to repair things. It works best for welding steel.
Shielding gas protects the weld by being a pocket of gas around the weld. The purpose of this gas is to keep normal air out, especially oxygen. It is different from flux because there is no liquid on the weld. There is only a gas around the weld. Because there is no liquid, it will not clean up dirt and other things on the metal. This means that the metal has to be clean before it is welded. If it isn't, the dirt and other things could cause problems. The gases that are usually used are argon, helium, and a mixture that is 3 parts argon and one part carbon dioxide. Other mixtures of gases can have nitrogen, hydrogen, or even a little bit of oxygen in them. One kind of welding that uses shielding gas is gas metal arc welding. It is usually used in factories to make things.
ІІІ. Language.
Ex.5. Match words and word combinations in column A with those in column B:
| A 1 protect 2. welding 3. oxygen 4. arc welding 5. melt 6. helmet 7. repair 8. grease 9. rust 10. hot sparks 11. nitrogen 12. evaporate 13. welder 14. burn 15. resistance welding | B 1. шолом 2. контактне зварювання 3. плавитися 4. зварювач 5. зварювання 6. захищати 7. випаровуватися 8. горіти, обпікати 9. кисень 10. іржа 11. змащення 12. гарячі іскри 13. дугове зварювання 14. ремонтувати 15. азот |
Ex.6. Match words and their definitions:
2. a) welding 1. the person, who joins pieces of metal by heating them b) rust 2. to change smth from a solid to liquid by means of heat c) to burn 3. joining pieces of metal by heating them e) to evaporate 4. a reddish-brown substance that is formed on the surface of iron f) to melt 5. to change into steam or gas and disappear g) welder 6. to destroy, damage or injure smth with fire or heat
Ex. 7 Find the ending of the sentences in the text:
1. All types of welding require that the hot metal ….
2. One kind of welding that does not use an arc is…..
3. Shielding gas protects the weld by ….
4. Flux can be made of many things, but it can be ….
5. Oxygen in the air will cause big problems in ….
6. There are two main ways to shield an arc welding, they are ….
7. Welding is a way of heating pieces of metal using ….
Ex.8 Ask questions to get the following answers:
1. Welding is a way of heating pieces of metal using electricity or a flame so that they melt and stick together.
2. The most common type is arc welding.
3. There are different kinds of arc welding too— shielded metal arc welding (SMAW) is a common type.
4. During welding, the flux will melt and some of it will evaporate.
5. One kind of welding that does not use an arc is Oxy-fuel welding (OFW), sometimes called gas welding.
6. Shielding gas protects the weld by being a pocket of gas around the weld
7. IV. Comprehension
8. Ex. 9. Agree or disagree with the following statements.
9. Welding is a way of heating pieces of metal using electricity or a flame so that they melt and stick together.
10. There are two kinds of welding: arc welding, and resistance welding.
11.. Anyone who is near arc welding doesn’t need to wear a special helmet or goggles.
12. One kind of welding that does not use an arc is Oxy-fuel welding (OFW), sometimes called gas welding.
13. All types of welding require that the cold metal have protection.
14. Flux can be made of many things, but it can be a solid or a paste.
15. Shielding gas protects the metal.
16. One type of welding that uses flux is gas tungsten arc welding.
Ex. 10 Answer the questions:
1. What is welding?
2. What is welding used for?
3. What should the welder do before starting his work?
4. What kinds of welding do you know?
5. What can cause problems in welding?
6. What is flux and gas shielding used for?
7. What gases are used?
Ex. 11. Complete the table:
Welding
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V Oral practice
