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1. Прочитайте та перекладіть українською мовою, перепишіть та письмово перекладіть весь текст.

The term "alloy steel" refers to steels which contain the modest amount of alloying elements and depend on heat-treatment. Alloy steels may be classified into several groups some of which can be further divided and subdivided. Each grade is specified to serve in definite application. Chromium-containing steels, for example, known as stainless, are typically used in automotive, chemical and military industries as well as in medicine, farm and mining machinery. High-speed steels, on the other hand, are selected for steady high-load conditions, such as pumps, turbi­nes, cutting tools, etc.

Cast irons are classified according to the amount and form of carbon or graphite or iron carbide. Gray irons, which provide excellent machinability with maximum compression strength, serve well as machine bases, engine blocks, water pipes, car wheels, etc. However, gray iron castings have low strength and shock resistan­ce. In many cases they are substituted by alloy gray irons. Alloy gray castings almost double the strength values and serve well to withstand high stresses. When extreme hardness or abrasion re­sistance are required high-alloy irons are specified.

Although ferrous metals are specified for more engineering needs than non-ferrous metals, non-ferrous materials provide a wider variety of properties and valuable characteristics. There is no branch of industry which does not make use of non-ferrous components. Availability, abundance and the cost of converting the metal into a useful form all play important past in selecting a non-ferrous metal. But they are very expensive. It is reasonable, therefore, to use them only when some characteristics not possessed by ferrous metals are required.

It is interesting to note that in spite of the fact that nearly 80% of all elements are called metals, only about two dozens of them are used as structural materials. Of the balance, however, many are used as coatings, in electronic devices, as nuclear materials, and as alloying elements. Most precious elements are available as sheets, wire, tubings, disks, cathodes, electrodes, catalysts or as solutions for coating.

Among other materials that serve an enormous number of engineering needs in fields dealing with noise, corrosion protection, electrical or thermal insulation mention should be made of plastics, rubbers, glass, ceramics, composites, carbides, etc.

2. Дайте відповідь на запитання:

1. What doubles the strength values?

2. What industries are сhromium-containing steels used in?

3. What are high-alloy irons specified?

4. What high-speed steels are selected for?

3. Визначте вірне речення чи невірне згідно змісту тексту.

1. Carbon-containing steels, for example, known as stainless, are typically used in automotive, chemical and military industries as well as in medicine, farm and mining machinery.

2. High-speed steels, on the other hand, are selected for steady high-load-conditions, such as pumps, turbines, cutting tools, etc.

3. The term “alloy steel” refers to steels which contain the modest amount of alloying elements and depend on heat-treatment.

4. Cast irons, which provide excellent machinability with maximum compression strength, serve well as machine bases, engine blocks, water pipes, car wheels, etc.

5. Alloy gray castings almost double the strength values and serve well to withstand high stresses.