Part II. oxide filmproduced on the surface of the heated metal often serves as the indicator of its temperature.

oxide film produced on the surface of the heated metal often serves as the indicator of its temperature.

Annealing is a heat treatment in which a material at high temperature is cooled slowly. After cooling the metal again becomes malleable and ductile (capable of being bent many times without cracking).

All these methods of steel heat treatment are used to obtain steels with certain mechanical properties for cer­tain needs.

Vocabulary:

to immerse [i'm3: s] — погружать to apply [a'plai] — применять intermediate [mta'mi.diat] — промежуточный oxide film ['oksaid] — оксидная пленка annealing [, as'nihn] — отжиг, отпуск cracking — растрескивание

General understanding:

1. What can be done to obtain harder steel?

2. What makes steel more soft and tough?

3. What makes steel more malleable and ductile?

4. What can serve as the indicator of metal tempera­ture while heating it?

5. What temperature range is used for tempering?

6. What are the methods of steel heat treatment used for?

Exercise 1.6. Translate into English the following words and word combinations:

1. температура нормализации

2. мелкозернистая структура

3. быстрое охлаждение

4. закаленная сталь

Unit 1

5. состав стали

6. окисная пленка

7. индикатор температуры

8. медленное охлаждение

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