Translate this text in written form.

1. Mankindhas used metals for centuries in gradually increasing quantities but only now they are employed in really great quantities.

2. Today we know more than seventy metals, the majorityof which are used in industry.

3. Of all the metals iron is the most important one.Absolutely pure iron is never prepared except for laboratory purposes. The irons and steels in use today are really alloys of iron, carbon and other substances. They can be made elastic, tough, hard, or comparatively soft.

4. Mechanical properties of metals are the result of their atomic structure. They include hardness, ductility and malleability which are of special importance in engineering.

5. Ductility is the capacityof a metal to be permanently deformed in tension without breaking.

Malleability is the capacity of a metal to be permanently deformed by compression without rupture.

6. These properties are similar to each other but not the same. Most metals increase these properties at higher temperatures.

7. The strengthof a metal is the property of resistance to external loads and stresses.

8. These mechanical properties are of great importance in industrial purposes because all parts and units made of iron and steel must meet up-to-date demands.

Exercises

Translate the words given in bold type into Russian.

Match English and Russian equivalents.

1. quantity 2. alloy 3. carbon 4. substance 5. tough(ness) 6. hard(ness) 7. ductility 8. malleability 9. tension 10. compression 11. rupture 12. strength 13. braking

а. жесткий (жесткость) b. углерод с. растяжение d. поломка е. количество f. ковкость g. разрыв h. прочность i. вязкость j. сплав k. твердый (твердость) 1. сжатие m. вещество

Translate these international words without dictionary.

Metal, industry, industrial, absolutely, laboratory, steel, elastic, mechanical, result, atom, atomic, structure, special, temperature.

Match questions and corresponding answers.

Questions

1. What is the most important metal?

2. What mechanical properties of metals do you know?

3. What is strength?

4. What is ductility?

5. What is malleability?

Answers

a. The capacity of a metal to be permanently deformed in tension without breaking.

b. Iron.

с.The capacity of a metal to be deformed by compression without rupture.

d. The property of a metal to resist to external loads.

e. Hardness, ductility and malleability.

Finish sentences, having chosen the corresponding word or word-combination.

1. The most important metal in use today is ....	a) carbon; b) iron; c) some other metal.
2. Ductility is the capacity of a metal....	a) to be permanently deformed in tension without breaking;
3. Malleability is the capacity of a metal....	b) to be permanently deformed by compression without rupture;
4. The strength of a metal is the property....	c) to resist to external loads and stresses.

Unit 8.2

Ferrous Metals and Steels

1. Ferrous metals consist ofiron combined with carbon, silicon and other elements. But carbon is the most important element in ferrous alloys.

2. Ferrous metals are used in industry in two forms: steel and cast iron, which differ in the quantity of carbon content.

3. Alloys consist of a simple metal combined with some other element. Steel is a ferrous material having some carbon content. There are two kinds of steel: carbon steel and alloy steels.

4. Carbon steel should contain only iron and carbon without any other alloying element.

5. Alloy steels are those in which in addition to carbon an alloying element is present. These alloying elements have an effect on the properties of steel. They increase its strength and hardness, for example, high percentageof chromium makes steel rust-resistant, and we call it "stainless steel".

6. Strength, ductilityand machinability are the most important industrial and commercial properties of steel. Such properties as resistance to wear, electrical conductivity, magnetic properties are important in special uses of metals.

7. According to their chemical and mechanical properties steels may be used in different branches of industry, for example, in machinebuilding, rocket engineering, automobile industry, etc.

Exercises