9.1. Прочитайте hoe крипционными знаками,
to subject [sab'dsekt] подвергать
condition [kan'difan] состояние, условие
initial [i'niJTJ начальный, первоначальный
to determine [di't*min] устанавливать, определять
reduction [n'dAkfan] сокращение
to achieve [a'tfkv] достигать
beyond [bi'JDnd] вше, свыше
to retain [n'tein] сохранять, удерживать
to join [с&эт] соединять
source [so:s] источник
available [a'veilabl] имеющийся в наличии, доступный
ые слова, пользуясь транс-i переведите предложения:
Metals can be subjected to large stresses without failure. Mercury is a liquid metal under normal conditions. The initial process of steel heat treatment is heating to desired temperature. The content of carbon in steel determines its properties.
The reduction of carbon content in steel makes it mild.
Only hard work allows to achieve success The metal is stretched just beyond its yield point. When stress is removed the part retains new shape. Parts can be joined by bolts.
Geysers [gaiza] are natural sources of heat. The information is available to anyone.
advantage [sd'varntidj] All types of welding преимущество have their own advantages and drawbacks.
considerably [kan'sidsrabh] Welded joints are значительно, гораздо considerably stronger
than other ones.
to harden ['ha:dn] Cold working hardens упрочнять(ся) metal.
application [,3epli'keiJnJ Plastics have found применение, использование, wide application in употребление car industry.
G^i 9.2. Match the following prefixes with their corresponding definitions:
1 inter— 2 post— 3 bi— 4 pre— 5 multi— 6 ex-
more than one; many
later than; after
before; in preparation
former and still living
between; among a group f> two; twice; double
9.3. Make up new words with these prefixes: 1 inter— 2 post— 3 bi— 4 pre- 5 multi— 6 ex-
...lingual
...date
...arranged
...national
...director
...graduate
...personal
h) ...husband
i) ...annual j) ...date
METALWORKING
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 recrystalli-zation temperature. These are 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
Rolling is the most common metalworking process. More than 90 percent of the aluminum, steel and copper produced are rolled at least once in the course of production. The most common rolled product 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
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 extrusions.
Tubes or other hollow parts can also be 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 back-extrusion (штамповка выдавливанием) 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 this process is the manufacturing of aluminium beer cans.
Дополнительный словарь:
metalworking металлообработка
shape fjeip] форма, формировать rolling f'roulin] прокатка extrusion [eks'tnr-зэпЭ экструзия, выдавливание drawing ['dro:m] волочение forging [fodjiri] ковка sheet [Ti:t] лист at least по крайней мере common ['komsn] общий billet ['bilit] заготовка, болванка
orifice ['onfis] отверстие cross section поперечное сечение
die [dai] штамп, пуансон, матрица, фильера, волочильная доска window frame [freim] рама
окна tube [tju:b] труба initial piece заготовка hollow ['hobu] полый thick-walled толстостенный mandrel ['maendnl] оправка,
сердечник loosely ['lu:sli] свободно, с
зазором fitting зд. посадка ram [rasm] пуансон, плунжер
0-§l 9.5. Answer the questions:
Why are metals so important in industry?
What are the main metalworking processes?
Why are metals worked mostly hot?
What properties does cold working give to metals?
What is rolling? Where is it used?
What is extrusion? What shapes can be obtained after extrusion?
What are the types of extrusion?
(Г^. 9.6. Find the following in the text: 1 .могут легко деформироваться 2.нужные формы
3.подвергать большим деформациям 4.зерна свободные от деформации б.температура перекристаллизации б.пластическая деформация сжатия 7. самый обычный процесс обработки металла
самое обычное изделие проката
отверстие фильеры
первоначальный
сложное сечение
пустотелые детали
свободно входящий плунжер
зазор между плунжером (пуансоном) и штампом
толщина стенки
(Й^ 9.7. Translate into English:
Способность металла перекристаллизовываться при высокой температуре используется при горячей обработке.
Перекристаллизация - это рост новых, свободных от деформации зерен.
Во время горячей обработки металл может подвергаться очень большой пластической деформации сжатия.
Холодная обработка делает металл тверже и прочнее, но некоторые металлы имеют предел деформации.
Листовой прокат может производиться горячим или холодным.
Поверхность холоднокатаного листа более гладкая и он прочнее.
Поперечное сечение фильеры для экструзии может быть простым или сложным.
Алюминиевые и медные сплавы являются наилучшими для экструзии из-за их пластичности при деформации.
Алюминиевые банки, тюбики для зубной пасты являются примерами использования штамповки выдавливанием.
10. Толщина стенки алюминиевой банки определяется зазором между пунсоном и штампом.
^TEXT 2