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

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.

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.

alloy - сплав

rusty - ржавый

stainless( rust-proof ) - нержавеющий

spring - пружина

КОНТРОЛЬНОЕ ЗАДАНИЕ №2 (Вариант3) (“АВ”, “ИМ”)

а) 1. The problem of the structure of matter is constantly occupying the minds of many scientists.

2. The production of this sophisticated device has required some new means of steel treatment.

б) 1. The intensity of this process is influenced by many factors.

2. Nation-wide programs are being worked out and implemented in production.

1. While working with any dangerous substances specialists put on special suits.

2. Molecular crystals are solids constructed of molecules held together by relatively weak forces.

3. Unless properly treated the metal must not be applied for this purpose.

4. Plastic parts are often too difficult to repair if broken.

1. You must be careful working with these dangerous substances.

2. The type of treatment may be more efficient than another one, but it may be too expensive.

3. The repair of that device can be done only by this specialist.

4. This part should be treated with special lubricant.

КОНТРОЛЬНОЕ ЗАДАНИЕ №2 (Вариант 4) (“АВ”, “ИМ”)

а) 1. . Thousands of researchers and scientists have taken part in the conference.

2. They are still looking for the suitable material for this purpose.

б) 1. Synthetic rubber products were developed between 1914 and the 1930s.

2. Many compounds can be decomposed when they are acted upon by different forms of energy.

1. Natural rubber is a thermoplastic material that becomes soft when heated and hard when cooled.

2. Matter composed of any chemical combination of elements is called a compound.

3. The machine-tool having some suitable for them characteristics required special lubricant.

4. To achieve a device with desired service life the engineers spent 2 years.

1. These metal parts had to be subjected to X-ray examination.

2. You may use this device to analyze its exact composition.

3. These new materials should to withstand much higher temperatures than the metals.

4. Ethylene gas can be obtained by cracking petroleum.

METALS

Metals are materials most widely used in industry because of their properties. The separation between the atoms in metals is small so most metals are dense. The atoms are arranged regularly and can slide over each other. That's why metals are malleable and ductile. Metals vary greatly in their properties. For example, lead is soft and can be bent by hand, while iron can only be worked by hammering at red heat.

The regular arrangement of atoms in metals gives them a crystalline structure. Irregular crystals are called grains. The properties of the metals depend on the size, shape, orientation, and composition of these grains. In general, a metal with small grains will be harder and stronger than one with coarse grains.

Heat treatment such as quenching, tempering, or annealing controls the nature of the grains and their size in the metal. Small amounts of other metals (less than 1 per cent) are often added to a pure metal. This is called alloying and it changes the grain structure and properties of metals.

All metals can be formed by different metalworking processes, but some require hot-working. Both metal fatigue (усталость металла) and creep (ползучесть) are taken into account by engineers when designing, for example, airplanes, gas-turbines, and pressure vessels for high-temperature chemical processes. The ways of working a metal depend on its properties.

dense - плотный

grains - зерна

coarse- грубый, крупный

alloying - легирование

quenching - закалка

tempering - отпуск после закалки

annealing - отжиг, отпуск

КОНТРОЛЬНОЕ ЗАДАНИЕ №2 (Вариант 5) (“АВ”, “ИМ”)

а) 1. The engineers have developed several types of metal treatment to harden it.

2. The problem of achieving low-cost material with the longest service life is still occupying the minds of many scientists.

б) 1. As a rule one great discovery is generally followed by numerous others.

2. The material properties are determined by many factors.

1. The smallest particle having all the characteristics of an element is called a compound.

2. Matter consists of one or more basic elements occurring in nature.

3. When heated to a certain temperature this alloy increases in volume.

4. Adding of some amount of carbon made it possible to obtain steel with desired properties.

1. New types of plastics had to be obtained for this purpose.

2. To measure the clearance between these two parts you can use this device.

3. This material should find its applications in the industry.

4. That part may withstand much lower temperatures than this one.

IV. Прочтите, перепишите и переведите.

METALWORKING PROCESSES

Extrusion is pushing the billet to flow through the orifice of a die. Products may have either a simple or a complex cross section. Aluminium window frames are the examples of complex extrusion.

Tubes or other hollow parts can be also extruded. The initial piece is a thick-walled tube and the extruded part is shaped between a die on the outside of the tube and a mandrel held on the inside.

In impact extrusion (also called back-extrusion) the workpiece is placed in the bottom of a hole and a loosely fitting ram is pushed against it. The ram forces the metal to flow back around it with the gap between the ram and the die determining the wall thickness. The example of the process is the manufacturing of aluminium beer cans.

Drawing consists of pulling metal through a die. One type is wire drawing. The diameter reduction that can be achieved in one die is limited but several dies in series can be used to get the desired reduction.

Forging is the shaping of a piece of metal by pushing with open or closed die.

Sheet metal forming is widely used when parts of certain shape and size are needed.

rolling - прокатка

extrusion -выдавливание, экструзия

drawing -волочение

forging - ковка

sheet-metal forming - штамповка листового металла

back-extrusion - штамповка выдавливанием

METALWORKING PROCESSES

Rolling is the most common metalworking process. More than 90% of aluminium, steel and copper produced is rolled at least once in the course of production. The most common rolled produced is sheet. Rolling can be done either hot or cold. If the rolling is finished cold, the surface will be smoother and the product stronger.

Extrusion is pushing the billet to flow through the orifice of a die. Products may have either a simple or a complex cross section. Aluminium window frames are the examples of complex extrusion.

Tubes or other hollow parts can be also extruded. The initial piece is a thick-walled tube and the extruded part is shaped between a die on the outside of the tube and a mandrel held on the inside.

Sheet metal forming is widely used when parts of certain shape and size are needed. It includes forging, bending and shearing. One characteristic of sheet metal forming is that the thickness of the sheet changes little in processing. The metal is stretched just beyond its yield point (2 to 4 percent strain) in order to retain the new shape. Bending can be done by pressing between two dies. Shearing is a cutting operation similar to that used for cloth.

Each of these processes may be used alone but often all three are used on one part. For example, to make the roof of an automobile from a flat sheet, the edges are gripped and the piece pulled in tension over a lower die. Next an upper die is pressed over the top finishing the forming operation and finally the edges are sheared off to give the final dimensions.

Forging is the shaping of a piece of metal by pushing with open or closed dies. It is usually done hot in order to reduce the required force and increase the metal's plasticity.

Open-die forging is usually done by hammering a part between two flat faces. It is used to make parts that are too big to be formed in a closed die or in cases when only a few parts are to be made. The earliest forging machines lifted a large hammer that was then dropped on the workpiece but now hot air or steam hammers are used, since they allow greater control over the force and the rate of forming. The part is shaped by moving or turning it between blows.

Closed-die forging is the shaping of hot metal within the walls of two dies that come together to enclose the workpiece on all sides. The process starts with a rod or bar cut to the length needed to fill the die. Since large complex shapes and large strains are involved several dies may be used to go from the initial bar to the final shape. With closed dies, parts can be made to close tolerances so that little finish machining is required.

Two closed-die forging operations are given special names. They are upsetting and coining. Coining takes its name from the final stage of forming metal coins, where the desired imprint is formed on a metal disk that is pressed in a closed die. Coining involves small strains and is done cold. Upsetting involves a flow of the metal back upon itself. An example of this process is the pushing of a short length of a rod trough a hole, clamping the rod, and then hitting the exposed length with a die to form the head of a nail or bolt.

STEEL

METALS

Metals are materials most widely used in industry because of their properties. The study of the production and properties of metals is known as metallurgy.

The separation between the atoms in metals is small, so most metals are dense. The atoms are arranged regularly and can slide over each other. That's why metals are malleable and ductile. Metals vary greatly in their properties. For example, lead is soft and can be bent by hand, while iron can only be worked by hammering at red heat.

All metals can be formed by drawing, rolling, hammering and extrusion, but some require hot-working. Metals are subject to metal fatigue and to creep (the slow increase in length under stress) causing deformation and failure. Both effects are taken into account by engineers when designing, for example, airplanes, gas-turbines, and pressure vessels for high-temperature chemical processes. Metals can be worked using machine-tools such as lathe, milling machine, shaper and grinder.

The ways of working a metal depend on its properties. Many metals can be melted and cast in moulds, but special conditions are required for metals that react with air.

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

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.

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.

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.

Наши рекомендации

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

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

Ш. Перепишите следующие предложения, подчеркните в каждом из них модальный глагол и его эквивалент Переведите предложения на русский язык.

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

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

← Предыдущая страница | Следующая страница →