Это методичка для спецалистов обучающихся по специальности сварочные технологии

1. Прочтите в слух данные слова и словосочетания и примеры с ними. Постарайтесь запомнить значения данных слов и словосочетаний.
Join – соединять
Joint – соединение, стык
Joining – соединение, процесс
We join metals and plastics by melting. Welding is one of methods of join metals and other material. After welding had been completed, the joint was leaned and inspected.
Melt – плавить, плавиться
Melting - плавление
Molten – расплавленный
Steel has a high melting point. The are energy is used for melting the base metal and electrode metal. Metals melted by the are joined together.
Fuse – сплавлять, соединять
Fusion – сплавление, соединение
Fusion welding. To weld metals it is necessary to melt and fuse them together. Metals are melted and fused together by the heat of the welding arc.
Edge – кромка
The edges of the joint should be cleaned and inspected before welding.
Surface – поверхность
The edges and the surface were heated, melted and fused together. Before welding it is necessary to clan and inspect edges and surfaces of the work piece.
Create – создавать
The are is created between the electrode and the work to be welded.
There are some methods of creating an are.
Source – источник
The electric are is a source of heat. There are many source of heat energy. “The Welding Journal” is a good source of practical and scientific information.
Refractory – тугоплавкий
Tungsten is a refractory metal. Some welding electrodes are produced of refractory metals.
Provide – снабжать, обеспечивать, предусматривать
The welding are provide heat necessary for melting metal edges and surfaces. When welding you must provide a number of important factors. A welding operator should be provided with all the necessary materials, tools and equipment. To make a good weld it is necessary to provide its protection from the atmosphere.
Establish – устанавливать, учреждать
The E.O. Paton Institute of Arc Welding in Kiev was established in 1932. The are may be established between the work and the electrode or between two electrodes.
Current – переменный
Direct – постоянный
Polarity – полярность
Straight – прямая
Reserve – обратная
There are two kinds of welding current: direct and alternating current (d.c. and a.c.).
Welding current is produced by welding machines. The welding machines are source of welding current. Direct current is produced in generators. Alternating current is produced in transformers. The d.c. has two polities: straight polarity (SP) and reserve polarity (RP). The alternating current changes its direction 50 times per second. Direct current are welding gives better results.
Penetrate – проникать, проваривать
Penetration – провар, проникновение
If the electrode is moved too fast (quickly) along the groove, there ewill be very little metal deposited and practically no fusion or penetration will be obtained. The depth (deep) of the crater indicates the amount of penetration or the depth of fusion. The application of bare electrodes usually results in poor penetration. Straight polarity electrodes can be used, but for better penetration, a reserve polarity will give best results.
Reduce – уменьшать, снижать
Increase – увеличивать
To produce a strong weld joint it is necessary to increase the length of the are. Metal to be welded must be heated to reduce the rate of cooling during welding.
Hold (held) – держать, удерживать
Holder – держатель
We use the electrode holder for holding an electrode. The electrode holder should be strong and light. There are many kinds of electrode holders.
Cable – кабель
Ground – земля, заземлять, заземление
There are two types of cable – electrode cables and ground cable.
The welding cables are usually produced of copper and aluminum.
Connect – соединять, присоединять
The electrode holder is connected with the electrode cable. The work is connected with the griund cable. The connection should be strong and positive.
Technique – технология, метод, техника
Technique of metal arc welding. In recent years new techniques, equipment and processes have been developed.
Strike – зажигать
There are some methods of striking an electric arc. To begin welding it is necessary to strike an arc. Where the arc strikes the base metal, metal is melted. After you are able to strike an arc, try to hold a short arc.
Maintain – поддерживать
After striking an arc it is necessary to maintain it. Strike an arc and try to maintain it. In order to be a good welder it is necessary to know the technique of striking and maintaining an arc.
Result – приводить к чему-либо
Too high current results in defects arc has resulted in the development of many welding processes.
Pool – лунка, ванночка, кратер дуги
After the arc is struck, it melts a small pool or crater on the surface of the base metal. Molten metal is carried over by the arc to the molten pool on the workpiec.
Deposit – наплав, наплавлять, насыпать
The electrode is melted and deposited in the crater. If we use a flux-coated electrode, the deposit will be better than with a bare metal electrode. A deposited metal is the metal that has been added by the welding process. In this process a special granulated flux was deposited an the joint to be welded. This welding technique provides a deep uniform fusion an good deposit.
Filler – присадочный (материал)
The metal electrode is a filler metal. The metal electrode conducts the current and provides a filler metal.
Groove – разделка, канавка
The groove was filler with the molten metal. There are many types of grooves. The groove is not necessary when welding sheet metals.
Circuit – цепь (сварочная, электрическая)
A welding circuit consist of a source of electric energy, two cable, a workpiec to be welded and other elements. One of the cables is used for the connection to the electrode holder and the other for the ground metal to complete the circuit. When current flows across the gap (distance, between the electrode and the joint) in an electric circuit, an arc is formed or created.
3. Подберите к английским глаголам соответствующие эквиваленты. Запишите полученные пары в тетрадь:
1. melt
2. join
3. fuse
4. create
5. strike
6. provide
7. flow
8. hold
9. connect
10. maintain
11. deposit
12. result (in)
13. increase
14. depend
15. penetrate
16. mean
17. ground
18. circuit
19. alternating
20. source 1. держать
2. поддерживать
3. переменный
4. подсоединять
5. заземлять
6. наплавлять
7. плавиться
8. источник
9. создавать
10. увеличивать
11. цепь
12. приводить к чему-либо
13. протекать, течь
14. зависеть
15. проворачивать
16. обеспечивать
17. зажигать
18. сплавлять, расплавлять
19. значит, означать
20. канавка, разделка
4. Прочтите и переведите группы слов, подобрав соответствующие эквиваленты к подчеркнутым словам:
1. welded joint
2. melting point
3. clean surface
4. edge of a work
5. source of current
6. refractory metal
7. straight polarity
8. alternating current
9. a.c. transformer
10. electrode holder
11. welding technique
12. molten pool
13. filler metal
14. consumable electrode
15. ground cable
16. welding circuit
17. good fusion 1. прямая (полярность)
2. трансформатор
3. технология
4. присадочный
5. соединение
6. сплавление
7. кромка
8. переменный
9. лунка, ванночка
10. заземление
11. поверхность
12. плавящийся
13. тугоплавкий
14. цепь
15. присадочный
16. источник
17. неплавящийся
5. Переведите слова правой колонки по образцу:
Образец:
Join – соединять
Connect - подсоединять
Hold - держать
Fill - наполнять
Ground - заземлять
Create - создавать
Melt - плавить
Fuse - сплавлять
Penetrate - проваривать
Consume - потреблять
Strike - зажигать
Deposit - наплавлять
Transform - преобразовывать
Generate - генерировать Joint – соединение
Connection
Holder
Filler
Grounding
Creating
Melting
Fusion
Penetration
Consumable
Striking
Deposit
Transformer
Generator
6. Прочтите группы слов. Переведите их устно, выбрав из правого ряда их русские значения:
1. workpiec metal
2. refractory
3. electrode metal
4. base metal
5. metal to be welded
6. molten metal
7. weld metal
8. wire metal
9. filler metal
10. consumable metal
11. deposited metal
12. protected metal
13. non-consumable metal 1. присадочный материал
2. металл шва
3. металл проволоки
4. неплавящийся металл
5. плавящийся металл
6. основной металл
7. тугоплавкий металл
8. наплавленный металл
9. расплавленный металл
10. металл, который надо сварить
11. металл электрода
12. свариваемый металл
13. защищенный металл
14. металл детали
7. Запишите в тетрадь данные слова и их русские значения:
1. metal-arc welding process
2. base metal to be welded
3. direct-current metal-arc welding
4. alternating-current welding machine
5. straight-polarity, direct-current metal-arc welding technique
6. transformer-type metal-arc welding current
7. low-voltage high amperage welding current
8. aluminium ground cable
9. high quality weld
10. combination welding machine
11. small molten metal pool
8. Прочтите предложения, укажите и запишите в тетрадь № предложений, где говорится о сварке. Обоснуйте свой выбор:
1. The circuit consists of two cables, a source of energy and other components.
2. the fabrication of iron and steel has greatly developed.
3. the increase of current results in the increase of penetration.
4. there are some methods of creating an arc.
5. the first problem was how to reconstruct and modernize the foundry shop.
6. the arc has a very high temperature and able to melt refractory metals.
7. there are two types of current: direct and alternating.
8. penetration is a major factor in making high quality welds.
9. the technique of machining the workpiec was developed by the shop specialists.
10. a holder is connected to the electrode cable.
11. cables connect the work and the electrode with the source of welding current.
12. the consumable electrode is hot only a conductor of electric current but is also a filler metal.
13. the arc bridge across the Irtysh river was built in 1978.
14. the knowledge of properties of the material enabled the operator to machine the work very quickly and exactly.
15. if you want to weld you should know the technique of striking and maintaining the arc.
16. too high current results in a deep fusion or penetration.
17. the current two-year plan of reconstruction of the foundry has been discussed and adopted at the meeting.
18. the metal electrode is a filler metal and during the process of welding is deposited in a molten pool.
19. direct current may be used under two conditions of polarity-straight and reverse.
20. to produce an alloy it is necessary to melt two or more metals and fuse them together.
9. Переведите устно выбранные Вами предложения;
10. Закончите предложения, используя слова, данные справа:
1. the intense heat is … by the arc.
2. the electric arc is the best … of
the heat energy.
3. the arc is able to melt … metals.
4. sometimes the arc is … between the two non-consumable electrodes.
5. there are two types of current … and …
6. the depth of fusion is named … .
7. the electrode … is used for holding an electrode.
8. when the electrode is in contact with the work, the … is completed.
9. the electric current and polarity, both … and … are an important factor in producing high quality welds.
10. the ... cables connect the … metal with a … of energy.
11. the … electrode is a conductor and at the same time a … metal.
12. intense heating … in melting the base metal and the electrode. Penetration
Circuit
Ground
To be created
Filler
To result (in)
Alternating
Source
To be produced
Reverse
Holder
Straight
Direct
Base
Refractory
Consumable
Quality
Property

11. Прочтите интернациональные слова, дайте их русские названия:
Metal, mechanical, pressure, process, intense, electric, energy, transform, temperature, concentration, industrial, zone, base, electrode, stability, factor, type, polarity, generator, special, transformer, voltage, amperage, reduce, crater, inspect, regular, cable, form, compensate, portion, contact, distance, absorb, ultraviolet, component, gas, ionize, discuss, proportion.
13. Закончите предложения, используя группы слов в правом ряду:
1. the arc is created …
2. the electric arc is …
3. the direct current is …
4. metal-arc welding is …
5. the electric arc produces …
6. flux coating is …
7. there are two …
8. the quality of weld …
9. a great amount of electric energy is … … produced by generators.
… transformed into heat energy.
… depends upon many factors.
… between the electrode and the work to be welded.
… a source of heat energy.
… a method of joining metals.
… used for proportion of the welding zone.
… methods of creating an arc.
… a great amount of heat energy.
13Переведите устно составленные вами предложения.
14. Информация: В тексте встречаются слова и словосочетания, образованные от глагола “mean”
а) to mean – означать, значить ‘DC’ means direct current.
a means – способ, средство The inert gas is a good means for protection the arc from the atmosphere.
c) by means of – посредством чего-либо The carbon electrode was held by means of a special holder.
15. Переведите устно предложения
1. this means that the current coming to the transformer is 220 V.
2. by means of electric arc, the great amount of electrical energy is transformed into heat energy.
3. an increase of current means deeper penetration and even burn though.
4. the other means such as heating, melting and fusing may be used.
5, metals to be welded were heated and melted by means of the electric arc.
6. this, of source, means higher welding current.
7. in many cases, this does not mean application of special technique.
8. modern means of welding inspection include ultrasonic, X-rays, and other techniques.
9. the heating of the surface is provided by means of the electric arc and by other means.
10. there are various means that can be applied to inspect the weld.
16. Информация: the PARTICIPLE 1 может входить в состав Независимого причастного оборота. Действие в обороте выражено не подлежащим, а существительным, входящим в оборот. НПО переводиться придаточным предложением с союзами: т.к., если, и, а, причём, прежде:
1. there are many methods of joining metals, welding being one of the best methods.
Имеется много способов соединения металлов, причём сварка один из лучших способов.
2. welding having been completed, the weld was cleaned and inspected.
После того, как сварка была завершена, шов был очищен и проверен.
17. Найдите предложения с независимым причастным оборотом и переведите их письменно:
1. sometimes, ferrous metals are joined by copper electrodes, no flux being applied.
2. aftor having been welded, the welds were inspected, the results being studied by the welding operators and inspectors.
3. the welding current is produced by special welding generators increasing or reducing the current.
4. tungsten being a refractory metal, we use it in tungsten-arc welding.
5. the electrodes developed for this technique are called contact electrodes, there being two types: Contact 15 and Contact 18 electrodes.
6. the Contact 18 electrodes give better results because the coating material produces a gas shield around the arc, the welding process being done in this shielding gas atmosphere.
7. when using electrode a very short arc must be maintained to fuse the edges of the joint.
8. the wire used in producing this type of electrodes varies from the other types, the difference being in the electrode coating.
18. Найдите предложения с инфинитивом в функции определения и переведите их письменно:
1. the weld to be inspected was cleaned.
2. the arc is created between the metal to be welded and the electrode.
3. in order to get better fusion you must increase the current.
4. it is necessary that the weld be made in horizontal position.
5. aluminium is a very good to weld metals.
6. welding is to be performed in all the position.
7. high-quality welds depend upon such factors as the metals to be joined, the machine to be used, the type of the current to be applied, the welding operator to perform these welds.
8. to make high-quality welds it is necessary to know the “Know-how and Know-why of welding technique”.
9. it is necessary that the electrodes to be used in this process be coated with special mineral coating designed for AC welding.
19. Информация: Инфинитив в предложении может выполнять функцию обстоятельства цели:
(in order) to produce an alloy it is necessary to heat and melt two or more metals and mix them.
Для того, чтобы получить сплав, необходимо …
You should apply direct current to weld these two metals.
Вы должны применить постоянный ток, для того, чтобы сварить эти два металла.
20. Переведите письменно предложения
1. in order to get good penetration to use proper current and polarity.
2. the electrode is held so as to maintain the arc.
3. it is required that proper current and polarity be applied to get deep and uniform penetration.
4. the electrode holder should be strong to hold an electrode in position you should to hold an electrode in position when welding.
5. to weld in vertical position you should know technique of vertical welding.
6. in order to make a weld it is necessary to strike the electric arc, maintain it and also to perform a number of other operations.
7. the electrode coating is used in order to protect the arc from the atmosphere.
8. to be a good welder you must know the “know-how” of welding.
21. Информация: Слово “number” может означать:
1. количество, ряд, номер
To must a weld it is necessary to perform a number of operations.
Чтобы выполнить шов, необходимо повести ряд операций.
You must know the number and type electrodes, for example, the number 2 VW-type electrodes.
Вы должны знать номер и топ электрода, например, “электроды №2 типа VW”.
22. Переведите предложения письменно:
1. there are a number of factories producing welding equipment for welding industry.
2. a great number of alloys have been developed for commercial application.
3. the welding operator experimented with the two numbers of electrodes: Contact 15 and Contact 18 electrodes.
4. the number of operations given in the instruction are: 1,2,5,11. it is necessary not only to follow this order but to consider a number of other factors.
23. Прочтите отрывки. В каких из них рассказывается о сварке:
a. The next problem is the electrode holder. This should be mechanically strong, light in weight and hold the electrode firmly in position during welding, but allow easy removal and replacement of an electrode. It must not be too not. The connection from the electrode holder to machine is made by cable.
b. This is one of the most important lessons in the course and you must repeat all the operations until the student who is operating is able to tell the student who works as an inspector what he is doing. After this has been done, and it will take some time to do it, then the students are to change place and repeat their operations.
c. Increased use of the hydraulic press in stamping plants has been seen during the past five years. Its flexibility as to length of stroke as well as controlled speed of stroke, make it particularly valuable to the job stamping shop. Today, hydraulic presses designed for both short and long strokes are of capacities up to 5.000 tons and more.
d. Be careful that you do not move the electrode too fast so that the deposited metal. Continue this operation until you are able to create the arc every time and stop it, and create again and maintain it in any position.
24. Прочтите отрывок А кадра 23 и скажите, о чем в нем рассказывается.
25. Прочтите отрывок А, и скажите, каким требованиям должен удовлетворять электрододержатель.
26. Информация: Повелительное предложение обычно начинается с глагола :
Например: Be careful. – Будьте внимательны!
Будьте осторожны!
Maintain. – Поддерживайте дугу
Do not look at the arc. – Не смотрите на дугу!
27. Переведите предложения устно:
1. do not play with the arc.
2. strike an arc and maintain it for some minutes.
3. inspect the penetration and the appearance of the weld.
4. hold the electrode in a vertical position.
5. feed the electrode into the zone of welding.
6. practice starting the arc and holding it.
7. never look at the arc without using a special shield.
8. do not stop training until you are able to start, maintain and stop the arc at any time and place you wish.
28. Прочтите отрывок Д кадра 23 и скажите по-русски, о чём говориться в повелительных предложениях-инструкциях:
Be careful …
Continue …
29. Прочтите текст А и скажите по-русски, о чём этот текст:
Text A.
1. metal arc welding is a method of joining metals by heating, melting and fusing the edges or surfaces together, no mechanical pressure being applied. Metal-arc welding is a fusion welding process.
2. in metal-arc welding, the intense heat, required to melt and fuse metal of the work to be welded, is created by an electric arc. The arc is most widely used source of electrical energy, and, therefore, heat energy for fusion welding. By means of the arc the great amount of electrical energy is transformed into heat energy in a small space (zone).
3. the electric arc is a highly desirable source of welding heat for a number of reasons. It has a very high temperature – 6.000 – 10.0000FF. (according to Fahrenheit) and is able to melt refractory metals and alloys having a very high melting point. The electric arc is the highest concentration of electrical energy used in any industrial process. This property permits (allows) it to produce a large amount of heat in the welding zone.
4. there are two simple ways of using the electric arc to provide welding heat. It can be established (created) between two electrodes or it can be created between the electrode and base metal to be welded. Of course, there are other ways of creating the arc.
5. the stability and other properties of the welding arc depend upon such factors as the current and polarity, the temperature and length of the arc, the type of electrode to be used and its flux coating, the metal to be welded and the type of the joint. Welding equipment is also of great importance.
30. Какой из заголовков вы выберете для текста А, прочитав текст ещё раз:
1. history of arc welding.
2. generators and transformers.
3. welding materials.
4. the arc and its characteristics features.
5. welding shop and its operation.
31. В тексте А – 5 абзацев. Какие из них приведенных заголовков соответствуют каждому из абзацев:
a. факторы, влияющие на качество дуги.
b. способы образования дуги.
d. характеристика дуги.
c. свойства дуги.
e. дуга – источник энергии.
32. Прочтите ещё раз текст А и расскажите по-русски о свойствах дуги (2 и 3).
33. Найдите информацию о том, какие операции выполняет дуга.
34. Скажите, от каких факторов зависит качество дуги.
35. Найдите в тексте А и переведите предложения со словами:
“by means of”, “a number of”.
36. Найдите и переведите предложения с герундием-определением.
37. Найдите и переведите предложения с инфинитивом - определением.
38. Найдите и переведите предложения с глаголом “can” и его эквивалентом.
39. Найдите и переведите предложения с Participle 2 – определением.
40. Прочтите отрывок и определите, является ли его содержание продолжением темы текста А.
Meta-arc welding requires a steady supply of electric power to develop the concentration heat at the arc. What is the arc? The electric arc represents the highest concentration of electric energy. Arc voltage varies in operation from 15 about 45 volts. Welding current may vary from 25 amperes when welding thin material to a maximum of about 1500 amperes and over.
Amperage is often referred to as “heat” in arc welding, but without voltage an arc cannot be made. Voltage is the force that delivers the current or heat to the electrode and across the gap (distance between the electrode and the work) to the surface of the work to be welded when the arc is struck.
The arc consists of a series of metallic participles and ionized gases crossing the gap from the electrode to the base metal. The arc has a very high temperature (up to 10.0000F) and is able to melt refractory metals and alloys used in construction of space rockets and sputniks.
Where the arc strikes the base metal, metal is melted and there is formed a pool of molten metal, or a crater.
41. Прочтите отрывок кадра 40 ещё раз и найдите предложения, отвечающие на данные вопросы. Прочтите выбранные предложения.
1. what is the electric arc?
2. what is amperage?
3. what is voltage?
4. what is the temperature of the arc?
5. in what large does the current vary?
6. what components does the arc consist of?
7. what metals and alloys is the arc able to melt?
42. Прочтите текст. Скажите, продолжает ли он тему текста А. как вы озаглавите текст,
1. if arc welding is performed by means of proper procedures it may be very efficient. Efficient arc welding can be defined as the joining of metals by fusion to give required strength and good weld appearance. Practically, this means that there must be accurate control of several variables. There are:
a. procedures or operations;
b. mechanical;
c. metallurgical.
2. under procedures are electrode size and type, current, position of electrode relative to the work, and, at last, arc speed and length. When the arc is moved slowly, there is wide pool of molten metal under the arc and force of the is expended in the molten pool instead of penetrating into (base) metal. It is clear that to get greater penetration, the arc should be moved more rapidly rather than slowly.
3. the proper arc length is very important. If the arc length is too short this results in porosity, slag inclusions and lack of fusion. On the other hand, when the arc length is too long, heat is lost (dissipated) in the air, much molten metal is lost in the form of spatter and the arc force is lost resulting in a winder pool and poor penetration.
4. as for the mechanical factors they are; edge preparation, gap or fit-up and position of joint, surface condition of metal and contour (geometry) of weld surface. Metallurgical variables are depth of penetration, analysis of base or parent metal.
43. Посмотрите текст кадра 42 ещё раз и укажите абзацы, где говориться об электрической дуге.
44. Прочтите выбранные вами абзацы и ответьте на вопрос, как влияет длина дуги и скорость сварки на качество шва.
45. просмотрите текст кадра 42 и перечислите все переменные, от которых зависит эффективная сварка.
46. Найдите в тексте кадра 42 и переведите устно предложения со словами: mean, result in, rather than, by means of.
47. Прочтите слова к тексту В и запомните их значения:
Frequency – частота
Determine – определять
Consume – тратить, расходовать
Consumable – плавящийся
The electrode is melted in the arc and is thus consumed.
Metal electrode is consumable since it is consumed during welding.
Tungsten and carbon electrodes are non-consumable.
Metal-arc welding is welding with a consumable electrode.
Tungsten electrode conducts the current but is not consumed.
48. Прочтите текст В и скажите, какие из данных заголовков соответствуют содержанию текста:
1. the arc and its features.
2. electrodes and their application.
3. welding machines.
4. penetration and weld appearance.
5. weld and its elements.
6. current and polarity.
Text B.
1. there are two kinds of current used for producing the electric arc. If the current flows in one direction, along the circuit, it is direct current (DC). If the current reverses (changes) its direction with regular frequency, it is alternating current (AC). Direct current may be used under two conditions of polarity: reverse polarity (RP) and straight polarity (SP). It means that the current may flow from the work to the electrode or from the electrode to the work. The polarity of direct current is important in determining the depth of fusion or penetration into two base metal and the rate (speed) at which the electrode is consumed.
2. the current for the welding arc is usually produced in special welding machines. There are several different types of welding machines used for producing welding current. Generally, direct current is produced in generators. Alternating current is produced by transformers type welding machines, i.e. transformers which take high-voltage low-amperage current and transform it into low-voltage welding current. This means that the current coming to the transformer, the voltage is reduced to 17-45 volts and the amperage increases to 150-1500 amperes and over.
49. Просмотрите текст В и скажите, каким абзацам соответствуют выбранные вами заголовки.
50. Прочтите первую часть текста и расскажите по-русски о различии между постоянным и переменным током.
51. Исходя из содержания текста В, скажите в чём заключается особенность постоянного тока и от чего зависит провар и скорость сварки.
52. Прочтите первую часть текста В, найдите и прочтите предложения, отвечающие на данные вопросы:
1. where is the welding current produced?
2. what machines produce DC?
3. what is the difference between the current coming to the transformer and the welding current?
53. Найдите в тексте В предложения, где говориться о значении полярности и переведите его.
54. Переведите предложения рассказывающие о получении переменного тока.
55. Прочтите отрывок и ответьте по-русски, какой части текста В он соответствует по содержанию:
D.C. welding machines or generators produce direct current. The direct current is know to be used under two conditions of polarity. Polarity is a problem of great importance. There are two kinds of polarity: straight polarity (SP) and reverse polarity (RP).
By straight polarity we mean that the electrode is connected to the negative terminal and the work is connected to the positive one. But if the current flows in the opposite direction, i.e. from the electrode to the work, we say that “reverse polarity” is used. By reverse polarity we mean that the work is negative and the electrode is positive.
56. Просмотрите отрывок кадра 55 ещё раз и скажите, какая новая информация о полярности содержится в отрывке.
57. Запишите в тетрадь и переведите письменно второе предложение отрывка кадра 55.
58. Переведите устно предложение со словом “one”.
59. Прочтите текст С, скажите по-русски о чём этот текст.
Text C.
Let us speak about the welding circuit and its components. The electrode used in metal-arc welding is held in a holder which is connected to one terminal (pole) of the welding machine. The base metal being welded is connected to the other.
The electrical connection is provided by two copper or aluminium cables. One is applied for the ground and called an electrode cable. The other applied for the ground plate or the base metal is called a ground cable. The ground cable is attached (connected) to the work and, when the electrode is brought in contact with the work, a circuit is completed and the arc is crated between the electrode and the metal to be welded.
60. Какой из заголовков соответствует содержанию текста С?
1. types of electrodes.
2. elements of the weld.
3. circuit and its components.
4. materials and welding equipment.
61. Закончите предложения, используя лексику текста С. Прочтите и переведите полученные предложения.
1. the electric circuit consist of …
2. there are two cables: …
3. the electrode cable is applied for …
4. the circuit is completed when …
5. the ground cable connects …
6. the arc is created …
62. Прочтите слова к тексту Д, запомните их русские значения.
Technique – техника, методика
Bring (brought) – подводить, подносить
Withdraw – отводить
Depth (deep) – глубина
Serve – служить
From aside – со стороны
Feed – подавать, подача
Uniform – равномерный
Advance – продвигаться
Clean – чистый, очищать
Groove – канавка, разделка
Maintain – поддерживать
63. Простите и расскажите по-русски о технологи сварки.
Text D.
If you want to join two metals by arc welding you should know the welding technique, i.e. the technological process of welding.
To begin welding it is necessary to strike an arc. The electrode held in a holder is brought in contact with the metal surface, withdrawn (separated) and held as so to create and maintain an arc. Since the space between the electrode and the base metal has highest resistance in the circuit, a tremendous amount of heat is developed by the electric arc at this point.
Intense heating results in melting the workpiec metal and forming a small molten metal pool or crater. The depth of the crater indicates the amount of penetration or depth of fusion.
Since the electrode is also melted by the heat of the electric arc, the electrode metal is deposited in a molten pool on the base metal. In this case the electrode metal served both electrical pole and the filler metal. As we see, the metal electrode supplies additional metal to the base metal, but in the case of carbon or tungsten arc, filler metal rod may be used, it being usually fed from aside.
After an electric arc has struck, it is maintained by a uniform continuous movement of the electrode toward the work to compensate for that portion of the electrode which has been melted and deposited in the weld. At the same time, the arc should be advanced at a uniform speed along the line of welding, i.e. the weld groove.
As for the metal in the crater, it is agitated and mixes the molten electrode metal with the base metal, forming a strong weld joint. After the weld is completed it is necessary to clean and inspect it.
64. Прочтите три отрывка. Скажите, какой отрывок не соответствует по содержанию тексту Д.
A.
Practice starting the arc and maintaining it, moving the electrode slowly over the work until you are able to start the arc once more. Move the electrode straight along the groove without zigzag motion of the electrode holder.
After you are able to strike an arc, hold a short arc and long arc to get better penetration and weld appearance.
Clean the welds, inspect them, criticize your work, ask criticism from others. Remember, because are melting a lot of metals, does not mean that you are welding.
If you have mastered welding in horizontal position, learn to weld in vertical and overhead position.
B.
Here are some instructions given by the instructor to the welding student.
Do not play with the arc. Make a definite plan and follow it in your practice.
Learn the fundamental principles of welding and reduce your problems to these principles.
Never look at the arc without using a shield to protect your eyes.
Hold the electrode in a vertical position, bring it to the work where the weld is to be done and then hold it there without striking an arc.
C.
The automatic atomic-hydrogen arc welding head developed at the Institute is a quite different modification of the same basic equipment for regulating welding arc length. Here two tungsten electrodes positioned at an angle toward each other are driven up and down, in order to regulate the distance between their tips, thus regulating the length and heat output of the atomic-hydrogen arc which is created between the two tungsten electrodes. The important difference in this equipment is that it drives two tungsten electrodes instead of one and at very speed (except when striking the arc) to compensate the gradual of the tungsten electrodes.
65. Просмотрите выбранный вами отрывок, ответьте на следующие вопросы по-английски.
1. what welding is described in the text?
2. what electrode do we use in the process?
3. how many electrodes are applied in this method?
4. when is the arc created?
5. is any gas used in this welding?
66. Прочтите слова к тексту Е и их русские значения.
Insulate – изолировать
Flexible – гибкий
Wear resistant – износостойкий
Consume – тратить, расходовать
Consumable – плавящийся
Composition – смесь, состав
Impurity – примесь
Float – плавить на поверхности
Eliminate – устранять, предотвращать
Handle – рукоятка
Shield – щиток (сварочный)
Helmet – шлем
Coloured – цветной
67. Прочтите текст Е и подберите к каждому абзацу заголовок
1. electrode flux coating.
2. electrode and their types.
3. cables and their features.
4. other welding equipment.
5. protection of welder’s face and eyes.
6. electrode holders.
Text E.
This is a story about welding materials and equipment.
1. welding current is conducted from the source of power to the arc by an insulated copper or aluminum cable. A very flexible cable is used between the electrode holder and the welding machine. This cable is designed for welding service.
For grounding the welding circuit, a less flexible, but equally wear resistant cable is used. The size of the cables used in welding depends upon the type of the material to be welded and the distance of the source of power.
2. the electrode is an important component of the electric circuit. We know electrodes to be divided into consumable and non-consumable electrodes. Tungsten and carbon electrodes are non-consumable. In the case of carbon and tungsten arc welding a filler metal may be fed from aside to supply an additional metal to the molten pool. As for the consumable electrodes, they are produced in the form of metal rod or wire, and for this reason provide a filler metal.
3. all the consumable electrodes are divided into bare and coated electrodes. An important advantage of arc welding is in the protection that a special mineral flux composition provides for the molten deposit. It is know that metal electrodes for the covered with flux coatings produce stronger welded joints as compared with those made with bare electrodes.
4. as it was mentioned, the electrodes are held in a special device-an electrode holder. The electrode holder is a clamping device for holding the electrode and is provided with an insulated handle for the operation’s hand. It should be mechanically strong, light in weight and hold the electrode firmly in position during welding.
5. we know that the arc is very hot and therefore it throws off both light and heat. To protect the operator’s face and eyes from the direct rays of the arc it is necessary to use a face shield or helmet. These shield or helmets are produced of pressed insulating material black in colour. The shield should be light in weight and comfortable to the welder. Shields are provided with special welding coloured lens absorbing the infrared rays, special goggles are used by welder’s assistants, foremen, inspectors and others working near the welder.
6. in addition to the equipment and materials described above, there should be available steel brushes for cleaning welds, tools for removing scale and slag from the surface of the weld and other shop equipment. Of course, in any welding shop you may find the equipment for welding inspection.
68. Прочтите текст Е ещё раз и ответьте на вопросы по-английски
1. what of electrodes are applied in welding?
2. how is a filler metal provided?
3. what is the difference between the two of cables?
4. what will you say about the electrode holder?
5. how are the welder’s face and eyes protected from welding rays?
6. say a few words about welding helmet.
69. Прочтите отрывок, скажите, какому абзацу текста Е он соответствует по содержанию
There are some functions performed by coating.
1. the coating gives off a protective gas, when heated by the arc, which shields the arc and molten metal from the atmosphere.
2. it stabilizes the arc by providing certain chemicals in the welding zone.
3. since the electrode coating is consumed at a rate slower than that of the metal of an electrode, it helps to direct the arc and the molten metal being deposited in the pool.
4. it also concentrates the arc stream and increases the rate of metal deposition and amount of penetration.
5. coating provides a flux, which helps to remove oxides and other impurities from the molten weld metal. It also provides slag which floats on top of the molten metal, providing additional protection from the atmosphere.
6. since the coating is an insulator of electricity, it eliminates short circuiting.
7. the coating may contain metal additions and therefore introduce the alloying elements into the weld.
70. Переведите отрывок кадра 69 письменно, используя слова, данные ниже:
Give off – выделять
Certain – определенный
Rate (speed) – скорость
Direct – направлять, прямой, постоянный
Stream – дополнительный
Eliminate – устранять
Short-circuiting – короткое замыкание, замкнутая цепь
71. Прочтите отрывок и скажите по-русски, продолжает ли он тему текста Е. В чём преимущества дуговой сварки металлическим электродом?
In electric welding there are two kinds of electrodes used, the carbon and metallic. The first mentioned is only to supply heat to the work, i.e. it is used for conducting the current and creating the arc.
In carbon-arc welding a filler rod may be added to the molten crater to provide the necessary metal.
As the metallic electrode is more often and universally used, this text will be confined only to the metallic type. The metallic electrode has a number of certain advantages over the electrode:
1. the metallic electrode is not only a conductor of electric current but it supplies a filler metal into the pool.
2. in metal-arc welding the heat setting and manipulation of the arc controls the amount of metal deposited and provides its exact location in the groove.
3. the amount of filler metal can be regulated by the speed at which the operator moves the metallic electrode.
72. Прочтите отрывки и ответьте по-русски на вопросы, поставленные к каждому отрывку.
А.
Какие меры предосторожности необходимо предпринять, чтобы избежать ожога лица и глаз при работе с дугой?
It is evident the arc is very hot. It is necessary that proper protection be used. For eye and face protection a special glass is used. It is very important that this glass be used at all times when looking at the arc. Never look at the arc without using a protective glass to shield eyes.
Direct exposure of a “flash” will result in a very painful burning of the eyes. Aspirin will help you to relieve pain and headacke.
Before to begin welding you must ask your assistant not to look at the arc without using a protective glass or goggles.
B.
1. где следует выполнять сварочные работы?
2. как избежать вредного воздействия дыма и газов при сварке?
3. где особо необходима вентиляция?
When working in the shop you must perform welding in separate rooms or cabins in order to eliminate the danger of burning eyes from reflected or direct rays of the arc to other workers.
All gas and arc welding operations result in a smoke and atmospheric contamination. Under normal working conditions the smoke from most arc welding operations in large open shops is not dangerous.
But artificial ventilation should be installed to carry off smoke into the open air and to provide good visibility and clean air when welding in small shops, rooms and cabins.
Ventilation is especially necessary if such metals as copper, zink or lead are to be melted.
73. Переведите отрывки без словаря (письменно)
А.
Instead of – вместо
Bellow – ниже
Provided – при условии
Match – совпадать
Maximum practical arc speed for the definite welding conditions is the main factors since this is necessary to fully use the penetrating action of the arc force.
Since increased arc speed results in increase of the metal deposited there is great economy in money, time, metal and current.
When the arc is moved slowly there is a small pool of molten metal under the arc and the force of the arc is lost in the molten pool instead of penetrating into the parent metal in the groove of the joint.
The molten metal does not fuse below the depth to which the arc penetrates. As we see, in slow arc speed there usually is a small
Pool of molten metal under the arc not providing deep penetration.
Of course, penetration not only depends upon the arc speed but also upon the current provided the arc speed matches the current increase.
B.
Lose – терять
Spread – распространяться
Spatter – брызги
From these facts, it is evident that to get greater penetration the arc should be moved more rapidly rather slowly.
An increase in current increases the arc force and provides deep penetration.
The quality of the weld also depends upon the arc length and the position of the electrode.
When the arc length is too long, heat is lost in the air, much molten metal is also lost in the form of spatter and the force is soread over a large area to give a winder molten pool.
Too short arc, as you know, may result in poor penetration or even short-circuiting.
In conclusion it has been show, that to obtain the highest welding speeds it is necessary to penetrate deeply into the base metal resulting in fusion of parent metal with the weld metal.
The amount of penetration and the economy are proportional to the current used, combining with the effectiveness of the use of arc force.
74. Итак, мы закончили обсуждение темы «Metal-Arc Welding». В результате проделанной работы Вы познакомились с определённым количеством терминов по вашей будущей специальности (в предложениях, которые даны ниже, термины подчёркнуты). Кроме того, многие предложения включают грамматические конструкции, обсуждаемые в 2. Прочтите и переведите предложения:
Предложения для контроля.
1. There are two methods of striking an arc.
2. Before to be welded the joint or groove should be cleaned and examined in order to provide deep penetration and sound weld deposit free from inclusions and impurities.
3. We know fusion-arc welding to be the process of heating, melting and fusing two or more metals together.
4. After creating an arc try to hold or maintain it.
5. Weld metal consists of the base metal and electrode metal, both these metal being fused in the molten pool on the surface of the metal to be welded.
6. The high current results in increasing depth of fusion and speeds welding rate.
7. Both the generator and transformer have two terminals for the electrode cable and ground cable.
8. The arc produces a great amount of heat and concentrates it in the joint rather than an the surface of all the work.
9. The electrode cable connects the source of source of power with the electrode holder.
10. As for grounding, it is provided with a ground cable.
11. As a rule, cables are made of copper and aluminum, are flexible and wearresistant, and have very high insulating properties.
12. Metal electrode provides a filler metal, this additional metal being deposited in the molten pool or crater.
13. Depth of fusion depends upon a number of factors.
14. Tungsten being a refractory metal, it is used for producing nonconsumble electrodes.
15. If used a filler rod may be fed from aside.
16. Vertical and overhead welding requires good knowledge of welding technique.
17. Too short arc resulted in shortcircuiting.
18. When the electrode is brought to the joint, the arc is established and the circuit is completed.
19. When striking an arc do not look at the without using a shield or helmet.
20. Current supply is provided by means of two cables.
21. The arc melts edges rather than all the surface of the work.