Welding History - A Story of Harnessing Heat

Тема урока: Welding History - A Story of Harnessing Heat

Цель урока:

• Образовательная ориентация на развитие неподготовленной монологической речи на основе прочитанного текста, понимание высказываний преподавателя и собеседника в различных ситуациях общения, в том числе при наличии незнакомых языковых средств; понимание учебных текстов

• Развивающая введение новой лексики – терминологии сварочного дела; развитие монологической и диалогической речи; формирование умения выделять главное / частное

• Воспитательная повысить мотивацию к изучению английского языка

Ход урока:

Part I

1.1. Приветствие

1.2 Озвучивание целей урока

Part II

2.1 Think of the answers for the following questions:

1. Why did welding become necessary?

2. Is welding a new profession?

3 Who were the first welders?

4. Who invented modern welding?

2.2. Введение новой лексики

New words

2.3 Reading the text.

Welding History - A Story of Harnessing Heat

Joining metal and welding history go back several illennia starting in the Bronze Age then Iron Age

in Europe then the Middle East. Welding was used in the Iron pillar in Delhi, India, about 310 AD, weighing 5.4 metric tons (picture at left). The Middle Ages brought forge welding, blacksmiths pounded hot metal until it bonded. In 1540,

Vannoccio Biringuccio released De la pirotechnia, which includes descriptions of the forging operation.

Renaissance craftsmen gained skilled in the process, and the welding continued to grow during the following centuries.

Welding was transformed during the 19th century. In 1800, Sir Humphrey Davy invented the electric arc, and advances in welding continued with the metal electrode by a Russian, Nikolai Slavyanov, and an American, C.L. Coffin late in the 1800s.

Acetylene was discovered in 1836 by Edmund Davy, but was not practical in welding until about 1900, when a suitable blowtorch was developed. At first, oxyfuel welding was the more popular welding method due to its portability and relatively low cost. As the 20th century progressed, it fell out of favor for industrial applications. It was largely replaced with arc welding, as metal coverings (known as flux) for the electrode that stabilize the arc and shield the base material from impurities continued to be developed.

In 1881 a Russian inventor, Benardos demonstrated the carbon electrode welding process. An arc was formed between a moderately consumable carbon electrode and the work. A rod was added to provide needed extra metal.

Thermite welding was invented in 1893, another process, oxyfuel welding, became well established. Around 1900, A. P. Strohmenger brought a coated metal electrode in Britain, which had a more stable arc, and in 1919, alternating current welding was invented by C.J. Holslag, but did not become popular for another decade.

Resistance welding was developed during the end of the 19th century, with the first patents going to Elihu Thompson in 1885, and he produced advances over the next 15 years.

In 1904 Oscar Kjellberg in Sweden, who started ESAB, invented and patented the covered electrode. This electric welding process made strong welds of excellent quality.

During the 1920s, major advances were made in welding technology, including the introduction of automatic welding in 1920, in which electrode wire was fed continuously.

Shielding gas became a subject receiving much attention, as scientists attempted to protect welds from the effects of oxygen and nitrogen in the atmosphere. Porosity and brittleness were the primary problems, and the solutions that developed included the use of hydrogen, argon, and helium as welding atmospheres.

2.4 Working with the text.

Find equivalents for the following words combinations in the text:

Угольный электрод, электрод с покрытием, защитный газ, торговое

судоходство, открытая печь, военный самолет, источник тепла, признавать преимущества электродуговой сварки.

True or false?

1.Arc welding was used to build the Iron pillar in Delhi, India.

2. The discovery of acetylene made it possible to achieve higher heatingtemperatures.

3. The first electrode used in welding was a covered one.

4. The British Prime Minister Winston Churchill was a famous welder.

Part III. The end of the lesson

3.1 Summing up of the lesson/подведение итогов урока

3.2 Marks of the lesson/оценивание

3.3 Home task – выучить новые слова (терминология сварочного дела, см 2.2.)