I. Read and translate the text.

Steel

The most important metal in industry is iron and its alloy-steel. Steel is an alloy of iron and carbon. It is strong but corrodes easily through rusting, although stainless and other special steels resist corrosion. The amount of carbon in steel influences its properties considerably. Steels of low carbon content (mild steels) are quite ductile and are used in the manufacture of sheet iron, wire and pipes. Medium-carbon steels containing from 0.2 to 0.4 per cent carbon are tougher and stronger and are used as structural steels. Both mild and medium-carbon steels are suitable for forging and welding. The inclusion of other elements affects me properties of the steel. Manganese gives extra strength and toughness. The addition of chromium gives extra strength and corrosion resistance, so we can get rust-roof steels.

П. Answer the questions to the text.

1) What is steel?

2) What are the main properties of steel?

3) What does influence its properties considerably?

4) What kinds of steel are suitable for forging and welding?

5) What does the inclusion of manganese give?

a) низкое содержание углерода b) противостоять коррозии c) пригодный для ковки и сварки d) нержавеющая сталь е) сплав железа и углерода

III. Match the sides.

1) Alloy of iron and carbon

2) Rust-roof steels

3) Low carbon content

4) Resist corrosion

5) Suitable for forging and welding

IV. Make up the sentences.

1) Strength, extra, gives, manganese.

2) Is, an, alloy, steel, of, and, iron, carbon.

3) Resistance, corrosion, the addition, of, gives, chromium.

4) The study, the production, of, metals, is, metallurgy.

5) Can, many, be, melted, metals.

V. Choose the right variant.

1) He was tired because he_______ hard all day

A worked B had worked C workes

2) Tomorrow_____ Friday

A will be Bis C was

3) The problem was______ we expected

A seriouser than B more serious man C serious than

4) My friend is interested_______ English

A on B about Cin

5) The day before yesterday we________ to this exhibition

A are invited B were invited C invite

МИНИСТЕРСТВО ОБРАЗОВАНИЯ И НАУКИ

ДОНЕЦКОЙ НАРОДНОЙ РЕСПУБЛИКИ ГОСУДАРСТВЕННОЕ

ПРОФЕССИОНАЛЬНОЕ ОБРАЗОВАТЕЛЬНОЕ УЧРЕЖДЕНИЕ

«ХАРЦЫЗСКИЙ ТЕХНОЛОГИЧЕСКИЙ ТЕХНИКУМ»

ГОСУДАРСТВЕННОГО ОБРАЗОВАТЕЛЬНОГО УЧРЕЖДЕНИЯ

ВЫСШЕГО ПРОФЕССИОНАЛЬНОГО ОБРАЗОВАНИЯ

«ДОНЕЦКИЙ НАЦИОНАЛЬНЫЙ ТЕХНИЧЕСКИЙ УНИВЕРСИТЕТ»

Variant №4

I. Read and translate the text.

Methods of Steel Heat Treatment

Quenching is a heat treatment when metal at a high temperature is rapidly cooled by immersion in water or oil. Quenching makes steel harder and more brittle, with small grains structure.

Tempering is a heat treatment applied to steel and certain alloys. Hardened steel after quenching from a high temperature is too hard and brittle for many applications and is also brittle. Tempering, that is re-heating to an intermediate temperature and cooling slowly, reduces this hardness and brittleness. Tempering temperatures depend on the composition of the steel but are frequently between 100 and 650°C. Higher temperatures usually give a softer, tougher product

Annealing is a heat treatment in which a material at high temperature is cooled slowly. After cooling the metal again becomes malleable are used to obtain steel with certain mechanical properties for certain needs.

П. Answer the questions to the text.

1) What is quenching?

2) What does this process make?

3) What do tempering temperatures depend on?

4) What do higher temperatures give?

5) What is annealing?

III. Match the sides.

1) quenching а) охлаждение метала

2) small grains structure b) состав стали

3) composition of steel c) температура нормализации

4) cooling the metal d) мелкозернистая структура

5) tempering temperatures e) закалка охлаждение