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V. Ответьте на вопрос: How does the carbon content influence the properties of steel?

КОНТРОЛЬНОЕ ЗАДАНИЕ №2 (Вариант 1) (“АВ”, “ИМ”)

I. Перепишите следующие предложения; подчеркните в каждом из них глагол-сказуемое и определите его видо-временную форму и залог. Переведите предложения на русский язык. В разделе (б) обратите внимание на перевод пассивных конструкций.

а) 1. Science of material strength has given mankind efficient means for increasing production volume.

2. The Academy of Sciences is still coordinating the work of this research institute and its laboratories.

б) 1. This engineer's report was followed by an intensive research work of others.

2. Heat energy is transmitted in two different ways.

II. Перепишите следующие предложения; подчеркните Particle I и Particle II и установите функцию каждого из них, т.е. укажите, является ли оно определением, обстоятельством или частью глагола-сказуемого. Переведите предложения на русский язык.

1. Nylon was the first synthetic fibre used in clothing.

2. This kind of treatment when used makes the metal heat-treatment.

3. The atom is built of negative electrons, positive protons and ordinary neutrons.

4. When worked by special substance this material will become more durable.

III. Перепишите следующие предложения; подчеркните в каждом из них модальный глагол или его эквивалент. Переведите предложения на русский язык.

1. One object may be larger than another one, but it may weigh less.

2. Mass can also be defined as a measure of inertia.

3. Man-made satellites had to use solar cells as a source of power.

4. Plastics should be reinforced by different kinds of fibres.

IV. Прочтите, перепишите и переведите.

METALWORKING PROCESSES

Metals are important in industry because they can be easily deformed into useful shapes. A lot of metalworking processes have been developed for certain applications. They can be divided into five broad groups: rolling, extrusion, drawing, forging, sheet-metal forming.

During the first four processes metal is subjected to large amounts of strain (deformation). But if deformation goes at a high temperature, the metal will recrystallize - that is new strain-free grains will grow instead of deformed grains. For this reason metals are usually rolled, extruded, drawn, or forged above their recrystallization temperature. This is called hot working. Under these conditions there is no limit to the compressive plastic strain to which the metal can be subjected.

Other processes are performed below the recrystallization temperature. This is called cold working. Cold working hardens metal and makes the part stronger. However, there is a limit to the strain before a cold part cracks.

rolling - прокатка

extrusion -выдавливание, экструзия

drawing -волочение

forging - ковка

V. Ответьте на вопрос: How many metalworking processes do you know?

КОНТРОЛЬНОЕ ЗАДАНИЕ №2 (Вариант 2) (“АВ”, “ИМ”)

а) 1. Chemical science is successfully solving many complex problems.

2. Quantum mechanics has greatly influenced the nuclear theory.

б) 1. Today many polymeric materials are produced on a massive scale.

2. The results of experiments are greatly influenced by many factors.

1. The equipment having all the desired characteristics is too expensive.

2. By building up a great number of high-quality devices it became the leading plant.

3. While working properly this mechanism required constant control from the engineers.

4. According to the drawing the given machine-tool had some rotating parts.

1. It can be obtained by special treatment.

2. That speed of operation may be achieved under special conditions.

3. This method should be used to simplify an assembly process.

4. These parts had to be subjected to some finish machining.

IV. Прочтите, перепишите и переведите.

STEEL

The most important metal in industry is iron and its alloy - steel. Steel is an alloy of iron and carbon. It is strong and stiff, 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 steel) 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 are suitable for forging and welding. High-carbon steels contain from 0.4 to 1.5 per cent carbon are hard and brittle and are used in cutting tools, surgical instruments, razor blades and springs. Tool steel, also called silver steel, contains about 1 per cent carbon and is strengthened and toughened by quenching and tempering.

The inclusion of other elements affects the properties of the steel. Manganese gives extra strength and toughness. Steel containing 4 per cent silicon is used for transformer cores or electromagnets because it has large grains acting like small magnets. The addition of chromium gives extra strength and corrosion resistance, so we can get rust - proof steels. Heating in the presence of carbon or nitrogen-rich materials is used to form a hard surface on steel (case - hardening). High-speed steels, which are extremely important in machine-tools, contain chromium and tungsten plus smaller amounts of vanadium, molybdenum and other metals.