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HEAT TREATMENT OF IRON AND STEEL





The heat treatment of steel after its formation is rather important. The treatment of steel is now an elaborate science of its own, and it is, of course, closely connected with the contents of the steel. The heating and the quenching are designed to bring about the arrangement of the crystalline structure in the desired way, to give the required properties. For example, steels containing a high percentage of carbon may be quenched after being heated to a high temperature to make them hard, and then moderately tempered to restore toughness.

No steel is used today that has not been tested. The simplest examinations are those made with magnifying glass or a microscope.

Spectroscopic or chemical analysis, X-ray examination, and magnetic or electrical tests may be applied. Specimens are also subjected to physical tests for toughness, strength, and hardness.

 

II.Переведите на русский язык следующие английские словосочетания:

1) for chipping off layers of metal 6) for measuring dimensions
2) for cutting blanks in parts 7) for removing bolts and nuts
3) with a series of small teeth 8) linear dimensions
4) from the surface of jobs 9) the combination bevel protractor
5) for sharpening and dressing 10) straight-edge cutting tools

 

III.Найдите в тексте английские эквиваленты следующих словосочетаний:

1) с поверхности обрабатываемых изделий 6) для измерения размеров
2) для нарезки заготовок деталей 7) для заточки и заправки режущих инструментов с прямоугольной кромкой
3) для снятия слоев металла 8) для нарезки шпоночных канавок
4) с множеством небольших зубьев 9)с помощью гаечных ключей
5) для отвинчивания болтов и гаек 10)отвертки используют

IV.Найдите в тексте слова, имеющие общий корень с данными словами. Определите, к какой части речи они относятся, и переведите их на русский язык:

driver, key, cut, screw, tight, practice, edge, out, great, side.

V.Задайте к выделенному в тексте предложению все типы вопросов: общий, альтернативный, разделительный, два специальных: а) к подлежащему, б) к любому члену предложения.

 

VI.Выполните анализ данных предложений, обратив внимание на следующие грамматические явления: формы и функции причастия, независимый причастный оборот, формы и функции герундия, герундиальный оборот. инфинитивные конструкции (сложное дополнение, сложное подлежащее), существительное в роли определения, функции слов one (ones), that (those), условные предложения (сослагательное наклонение 1 и 2 типов):



 

1. The combination bevel protractor (angle) is used for measuring.

2. Oilstones are necessary for sharpening and dressing.

3. These cutting tools are used for precise finish of flat and curved surfaces in cases when it is necessary to obtain perfect mating surfaces on contacting parts.

4. Chisels are widely used for chipping off layers of metal from the surface of jobs, for cutting blanks in parts, as well as for cutting grooves, slots and keyways.

5. They wanted files to be cutting tools.

 

VII.Ответьте на вопросы по тексту:

 

1. What mechanic’s tools do you know?

2. What processes are chisels used for?

3. What are the size of files?

4. What are scrapers?

5. What tool is performed for most ordinary work such as screwing in and out screws used?

6. What is the vernier caliper?

7. What is the steel rule used for?

 

VIII.Составьте аннотацию на текст (2-3 предложения).

IX.Составьте реферат на текст (10-15 предложений).

X. Составьте план текста и перескажите текст.

ВАРИАНТ № 5

I. Прочитайте и переведите текст:

MACHINE PART FASTENING

Some forms of fastening, such as welding, riveting, direct threaded joints, bolting or keying, must be used in assembling the individual members to form a complete machine or structure.

Riveting makes a permanent joint that cannot be disassembled without destruction of the rivets. In making up this joint, the rivet is inserted in a punched or drilled hole and the second head is formed by a rivet set, air hammers, and air- or hydraulic-pressure machines. Welding, soldering, brazing and fight fits belong to permanent joints. Welding is the method of joining metals by pressure, after heating them to a plastic or semimolten state, or of joining metals by fusion alone.

Threaded bolts and screws are used to hold together machine parts that must be readily disassembled, and parts of large machines that must be built in small units for ease in manufacturing, assembling or shipping. The forms of common screw threads are shown in the figure.

The following data of every screw are very important: the pitch, the lead, major diameter (nominal diameter), and minor diameter (root diameter). A thread may be a left-hand or a right-hand one. Bolt sizes are designated by the outside diameter of the thread and by the length under the head. Through bolts are used where both the head and nut can be made accessible by the use of flange connections. Cap screws have no nuts; the screw passes through a clearance hole in one member and threads into the mating member. To prevent nuts from working loose, special washers, pins, and nuts are used as locking devices.

Knuckle joints are used to connect two rods or bars when a small amount of flexibility or movement is necessary.

HOT WORKING

When the mechanical working of metal or alloy takes place above the recrystallization temperature, the process is known as hot working.

In a hot-worked metal or alloy the grains are being continually formed as hot working continues, and the size of grains depends on the temperature. The smallest grains are formed when the temperature is just above the recrystallization temperature, and this is usually the best finishing temperature for hot working operations.

Hot rolling and forging are very widely used in the fabrication of metal shapes, and, even when the finishing operation to be cold working, the preliminary shaping is done by hot working.

The temperature of the metal for hot working depends on the metal or alloy, and there is a best temperature range and a best finishing temperature in each case.

II.Переведите на русский язык следующие английские словосочетания:

 

1) in assembling the individual members 6) use of flange connections
2) without destruction of the rivets 7) data of every screw
3) is inserted in a drilled hole 8) a clearance hole
4) joining metals by pressure 9) knuckle joints
5) are designated by the outside diameter of the thread 10) a small amount of flexibility

 

 

III.Найдите в тексте английские эквиваленты следующих словосочетаний:

1) без разрушения заклепок 6) соединение металлов под давлением
2) использование гребневых соединений 7) форм прикрепления
3) характеризуются внешним диаметром резьбы 8) сварка соединяет металлы
4) в сборке отдельных деталей 9) как блокирующее устройство
5) вставляется в просверленное отверстие 10) соединить два прута

IV.Найдите в тексте слова, имеющие общий корень с данными словами. Определите, к какой части речи они относятся, и переведите их на русский язык:

fast, with, assemble, hand, access, connect, clear, flexible, move.





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