Text 2. From the History of Welding

 

Welding is a technique used for joining metallic parts usually through the application of heat. This technique was discovered during efforts to manipulate iron into useful shapes. Welded blades were developed in the first millennium AD, the most famous being those produced by Arab armour ers at Damascus, Syria. The process of carburization of iron to produce hard steel was known at this time, but the resultant steel was very brittle. The welding technique - which involved interlayering relatively soft and tough iron with high-carbon material, followed by hammer forging - produced a strong, tough blade.

In modern times the improvement in iron-making techniques, especially the introduction of cast iron, restricted welding to the blacksmith and the jeweler. Other joining techniques, such as fastening by bolts or rivets, were widely applied to new products, from bridges and railway engines to kitchen utensils.

Modern fusion welding processes are an outgrowth of the need to obtain a continuous joint on large steel plates. Rivetting had been shown to have disadvantages, especially for an enclosed container such as a boiler. Gas welding, arc welding, and resistance welding all appeared at the end of the 19th century. The first real attempt to adopt welding processes on a wide scale was made during World War I. By 1916 the oxyacetylene process was well developed, and the welding techniques employed then are still used. The main improvements since then have been in equipment and safety. Arc welding, using a consumable electrode, was also introduced in this period, but the bare wires initially used produced brittle welds. A solution was found by wrapping the bare wire with asbestos and an entwined aluminum wire. The modern electrode, introduced in 1907, consists of a bare wire with a complex coating of minerals and metals. Arc welding was not universally used until World War II, when the urgent need for rapid means of construction for shipping, power plants, transportation, and structures spurred the necessary development work.

Resistance welding, invented in 1877 by Elihu Thomson, was accepted long before arc welding for spo t and seam joining of shee t. Butt welding for chain making and joining bar s and rod s was developed during the 1920s. In the 1940s the tungsten-inert gas process, using a nonconsumable tungsten electrode to perform fusion welds, was introduced. In 1948 a new gasshielded process utilized a wire electrode that was consumed in the weld. More recently, electron- beam welding, laser welding, and several solidphase processes such as diffusion bonding, friction welding, and ultrasonic joining have been developed.

 

After-reading activity

 

Refer the following statements to each of the passages of the text:

 

1. Application of welding techniques is decreasing nowadays.

2. Welding originated from the attempts to shape metal into useful forms.

3. Resistance welding is one of the earliest types of joining metals.

4. Industrial development in the 1950-s expedited (ускорять) the advance of welding technologies.

 

Speaking

 

True or false?

 

1. Only heat is used for joining metallic parts in welding.

2. The process of carburization of iron is rather new.

3. The blacksmith and the jeweler continue to use welding techniques in their work.

4. Welding is the only technique of joining metallic parts.

5. The modern electrode consists of a bare wire with asbestos.

6. Arc welding was not used after World War II.

7. Diffusion bonding and friction welding are solid-phase processes.

8. Rivetting is now widely used for producing an enclosed container such as a boiler.

 

Answer the following questions:

 

1. What is welding?

2. How was welding discovered?

3. Who were the first welders?

4. What did the first welding technique for making blades involve?

5. Did the improvement in iron-making techniques conduce to the development of welding?

6. Is it efficient to apply riveting for making boilers?

7. When did gas, arc and resistance welding appear?

8. What was the quality of the welds produced by the arc welding using bare wires like?

9. What does the coating of the modern electrode consist of?

10. What are the years 1877, 1916, and 1948 remarkable for in terms of welding?

 

 

Translate from Russian into English:

 

1. Арабских оружейников, изготавливавших кованые клинки, можно считать первыми сварщиками.

2. Появление      методов сварки   плавлением    было     обусловлено необходимостью производства изделий из крупнолистовой стали.

3. Впервые сварка стала использоваться в массовом производстве во время первой мировой войны.

4. Вторая мировая война ускорила внедрение электродуговой сварки. 5. Современный сварочный электрод имеет сложное покрытие, состоящее из композитных материалов.

6. Помимо сварки, клепка и болтовые соединения являются основными методами соединения металлов.

 

Writing

 

Write a short report on the history of welding mentioning:

 

Dates: first millennium AD,1540, 1800, 1836, 1881,, 1877, 1881, 1892, 1900, 1904, 1907, 1924, 1935, 1948.

Names: Alexander, Jones, Kennedy and Rothermund, Morehead and Wilson, Oscar Kjellberg, Benardos, Russell Meredith, Edmund Davy, Nikolai Slavyanov, C.L. Coffin, Vannoccio Biringuccio, Sir Humphrey Davy.

Places: Syria, Russia, Sweden, the US, Britain;

Inventions: modern electrode, resistance welding, oxyacetylene process, MIG, TIG, atomic hydrogen welding process, submerged arc welding, carbon electrode.

 

Lead-in

 

Think of the answers for the following questions:

 

1. How can welding influence the history of a country? 

2. In what fields of industry, in your opinion, is welding especially important?

3. What modern machines and structures cannot be produced without welding processes?

4. What welding process, arc or gas ones, has played a more important part in developing new technologies? What     particular aspect(s) of this process/processes is/are of significance for industry development?

 

Vocabulary

 

war effort	военная экономика
rivetting	клепка
brittle fracture	хрупкий излом
notch	зубец; вырез, паз, пропил, прорез
crack propagation	развитие трещин
fusion welding	сварка плавлением
field welding	сварка в полевых условиях, сварка при монтаже
toughness	твердость
planeload	полная загрузка самолета
X-ray inspection	рентгенодефектоскопия
induction heating	индукционный нагрев
structural steel	конструкционная сталь
rolled steel	стальной прокат
fillet weld	угловой сварной шов
contact face	поверхность контакта
electroslag welding	электрошлаковая сварка

 

Pre-reading activity

 

Find the following figures in the text and say what they relate to:

 

140, 20, 5171, 2200, 1945, 525, 531, 2710, 250,000, 58, 117, 1915, 1931, 1977, 120, 176,000, 500,000, 586,000, 17,000, 80, 373,500, 52.

 

Model: 2200 - 2200 passengers were killed on the Mississippi River when the steamboat Sultana blew up.