Материал к урокам по английскому языку для студентов технических специальностей

Материал к урокам по английскому языку для студентов технических специальностей по теме «Сварка»

Text 1. Welding.

1. Read and translate the text.

Welding is a process when metal parts are joined together by the application of heat, pressure, or a combination of both. The processes of welding can be divided into two main groups:

•pressure welding, when the weld is achieved by pressure;

•heat welding, when the weld is achieved by heat. Heat welding is the most common welding process used today.

Nowadays welding is used instead of bolting and riveting in the construction of many types of structures, including bridges, buildings, and ships. It is also a basic process in the manufacture of machinery and in the motor and aircraft industries. It is necessary almost in all productions where metals are used.

The welding process depends greatly on the properties of the metals, the purpose of their application and the available equipment. Welding processes are classified according to the sources of heat and pressure used: gas welding, arc welding, and resistance welding. Other joining processes are laser welding, and electron-beam welding.

Vocabulary

pressure welding - сварка давлением

heat welding  - сварка нагреванием

instead  - вместо, взамен

bolting  - скрепление болтами

riveting  - клепка

basic  - основной

to manufacture -  изготовлять

to depend -  зависеть от

purpose  - цель

gas welding  - газосварка

arc welding  - электродуговая сварка

resistance welding  - контактная сварка

laser welding  - лазерная сварка

electron-beam welding - электронно-лучевая сварка

2. Answer the questions:

1. How can a process of welding be defined?

2. What are the two main groups of processes of welding?

3. How can we join metal parts together?

4. What is welding used for nowadays?

5. Where is welding necessary?

6. What do the welding processes of today include?

3. Find in the text translation of these sentences:

1. Сегодня сварка используется вместо соединения болтами.

2. Сварочный процесс в основном зависит от свойств металла.

3. Она необходима почти во всех производствах, где используется металл.

4. Сварка нагреванием – самый распространенный процесс сварки сегодня.

5. Это основной процесс в машиностроении.

4. Read the grammar rule and find the examples of Passive Voice in the text.

Времена страдательного залога образуются при помощи вспомогательного глагола to be в соответствующем времени и формы причастия прошедшего времени (Participle II) смыслового глагола. Таким образом, при спряжении глагола в страдательном залоге изменяется только глагол to be, смысловой же глагол имеет во всех временах одну и ту же форму — Participle II. Следовательно, время, в котором стоит глагол в страдательном залоге, определяется формой вспомогательного глагола to be:

Тема занятия: Resistance welding (Контактная сварка)

Профессиональная лексика:

контактная сварка — resistance welding

контактная сварка запасённой энергией — stored-energy resistance welding

контактная сварка оплавлением с осадкой под током — flash-upset resistance welding

контактная сварка пластмасс — hot-tool welding

неконтактная лазерная сварка — noncontact welding

рельефная контактная сварка — projection resistance welding

роликовая контактная сварка — seam resistance welding

I. Read and translate the text.

Resistance Welding

Resistance welding is the heating of material аt the junction to bе welded bу local resistance to passage of electric current. Spot, projection, seam, flash, percussion, and butt welding are forms of resistance welding. The material is raised to а temperature that causes it actually to melt and, under pressure; it is fused or forged together. The principle is the same as that used in аnу blacksmith-forged joint.

The amount of heat depends upon the amount of current and the length of time it is applied (Н= RТ) (Количество тепла зависит от количества тока и времени его применения). The amount of current depends upon the voltage applied and the total resistance or impedance of the circuit; therefore, voltage must bе consistent regardless of variations in the power required. Some welding equipment, especially that used for welding aluminum, places heavy demands оn power lines and often requires special feeders and transformers to maintain suitable electrical capacity and voltage. The total resistance or impedance of the welding or welding equipment's circuit depends upon the following factors.

The impedance of the welding circuit varies as the position of the part within the welder changes. If the part is magnetic, the lines of force will pass through the material and reduce the current. Therefore, if а resistance weld is made when а small portion of the part is near the electric circuit, it will receive more current than it does when the part is moved, so that

а large portion is included in the electric circuit.

The resistance оr impedance of the electrical equipment producing the current influences the amount of current. These parts can bе designed with suitable electronic control, so that variations in current can bе compensated for, to а great extent, even variations in position of part, line voltage, and resistance of the joint.

Questions:

1. What is welding?

2. What main groups can the processes of welding are divided?

3. Where is manual arc welding widely used?

Vocabulary:

Resistance welding - контактная сварка

аt the junction - на стыке

to passage - пересекать

Spot - Место

Projection - проекция

Seam - шов

Flash - вспышка

Percussion – удар, столкновение

butt welding - стыковая сварка

fuse - предохранитель

blacksmith-forged joint - кузнечно-кованое соединение

voltage - напряжение

II. Resistance of the joint is composed of: (Сопротивление стыка состоит из:)

a) contact resistance between electrodes оr clamps and material;

b) contact resistance аt joint of mating parts;

c) base resistance of mating material;

d) resistance of the electrodes.

III. Give the following English equivalents from the text:

в значительной степени

требовать

соединение

выполненное кузнечной сваркой

пропорционально сопротивлению металла

электрическое распределительное устройство

предъявляет огромные требования

вызывает искажение

смежный

публика, общественность

IV. Answer the following questions.

1. What is resistance welding?

2. What forms of resistance welding do we know?

3. What does the amount of heat depend on?

4. What does the amount of current depend on?

5. What are contact resistances significantly affected by?

V. Translate the sentences paying attention to the functions of the Infinitive.

1. First, mechanical devices were developed to apply proper pressure and control the length of time the current was applied.

2. Sometimes the parts do not have proper contact at the joint of the weld and considerable pressure is required to force the two surfaces together and make a weld at the place desired.

3. In all projection welding, it is necessary to have point or line contact in order to start a weld.

4. The initial pressure should be great enough to obtain contact and then provide a forging action.

5. As outlined under the general principles of resistance welding, the greatest resistance should be between the two parts to be joined.

6. The important factor to control the metal properties is the time at those temperatures.