Grammar: Compound Conjunctions.
Word-formation: Conversion.
Speaking: Properties of metals and alloys.
Practise the reading of the words:
| medium | [′mI:djəm] |
| temperature | [′temprItòə] |
| although | [ɔ:l′ðou] |
| ductile | [′dΛktaIl] |
| characterize | [′kærIktəraIz] |
| thermal | [′θə:məl] |
| artificial | [/ɑ:tI′fIòəl] |
Learn the pronunciation and meaning of the words:
| nodular cast iron | чугун с шаровидным графитом | |
| malleable cast iron | [′mælIəbl] | ковкий чугун |
| flake | зерно (минерала) | |
| ferrite | феррит (структурная составляющая стали и чугуна, представляющая собой чистое железо) | |
| pearlite | [′pə:lIt] | перлит (структурная составляющая стали, представляющая собой мельчайшую смесь железа и карбида железа) |
| damping | амортизация | |
| roller | ролик, каток, вал, валец | |
| rolling mill | прокатный стан | |
| manganese | [/mæηgə′nI:z] | марганец |
| foundry | литейное дело, литье, литейный цех | |
| surgery | [′sə:dჳərI] | хирургия |
| oxygen | [′ɔksIdჳən] | кислород |
Vocabulary development: word building:
Exercise 1. Translate the original and derivative words, using a dictionary and create several new words by adding suffixes:
| verb | noun (abstract) | noun (personal) | adjective |
| to transform | transformation transformer | - | - |
| ограничивать | limit limitation | - | limitary ограничивающий limited limitless |
| to add | addition additive | - | additional |
| формировать | form formation former | former | formative бывший, прежний |
| to desire | желание desirability | - | desirous desirable |
Exercise 2. Translate the sentences, paying attention to compound conjunctions:
1. In ancient states the use of iron, either cast or wrought, was rather limited.
2. It is known that both ferrous and non-ferrous metals are widely used.
3. The carbon content may be either less or higher than 2,14 %.
4. Graphite flakes in gray cast iron are surrounded by either ferrite or pearlite.
5. Both ferrous and non-ferrous metals possess many characteristic features.
6. Some alloying elements can form either compounds or carbides.
Text
Read the text about the properties of some metals resulting in alloys:
Metals and Alloys
Each metal possesses certain distinct combinations of properties, that may be varied for specific engineering applications by alloying it with relatively, small amounts of other materials. The term “alloy” is used to determine a material containing more than one chemical element. The properties of the alloy being determined by the properties of the elements it consists of. The main alloying element in ferrous metals is carbon (C). Depending on the amount of carbon, alloys have different properties. The carbon content may be either less or higher than 2,14 %. Below this amount of carbon material undergoes hard cast eutectoid* transformation, while above that limit ferrous materials undergo easy cast eutectic** transformation. The ferrous alloys with less than 2,14 % C are termed as steels, and the ferrous alloys with higher than 2,14 % C are termed as cast irons.
Steels are alloys of iron and carbon with other alloying elements. Steels can be low, medium and high carbon. Cast irons may contain 3.0–4.5 % C along with some other alloying additions and melt at lower temperatures than steels. Cast irons are specified as gray, white, nodular and malleable cast irons.
Gray cast iron consists of carbon in the form of graphite flakes, which are surrounded by either ferrite or pearlite. Although gray cast irons are weak and brittle they possess good damping properties and are applied in base structures, beds for heavy machines as they have high resistance to wear.
White cast irons are very brittle. Hence their use is limited to wear resistant applications, such as rollers in rolling mills. Usually white cast iron is heat treated to produce malleable iron.
Malleable cast irons are stronger and possess high amount of ductility. Their typical application include railroad, connecting rods, marine and other heavy-duty services.
Nodular (or ductile) cast irons are stronger and more ductile than gray cast irons. Their applications are pump bodies, crank shafts, automotive components, etc.
Non-ferrous alloys are also widely used in engineering.
Aluminium alloys are characterized by low density, high thermal and electrical conductivities, good corrosion resistant characteristics. But the great limitation of these alloys is their low melting point (660 єC). Aluminium alloys with Lithium (Li), Magnesium (Mg) and Titanium (Ti) are paid much attention when vehicle weight reduction is concerned. They are very useful in aircraft and aerospace industries. Common applications of Al alloys include: beverage cans, automotive parts, bus bodies.
It is worth mentioning that aluminium alloys are used where light weight is needed. They are also used because of their resistance to corrosion. Aluminium alloys also possess desirable property of thermal and electrical conductivity.
Beside aluminium alloys there are some other non-ferrous ones: copper, lead, tin, zinc, nickel alloys. It is necessary to point out that both ferrous and non-ferrous metals possess many characteristic features: elasticity, ductility, malleability, toughness, brittleness, hardness, wear resistance and corrosion resistance. Copper alloys form such metals, as brass and bronze. The aluminium alloys with copper, manganese, silicon and nickel are widely used where corrosion resistance, high electrical conductivity, ductility and high strength are needed. Zinc alloys have some advantages over others in foundry: excellent casting properties, machinability and lower density than bronze.
In machinery there is one of the most interesting metals, called titanium. Titanium has wonderful property – it is completely inert in biological media and that is why is being widely used in medical purposes for making artificial joints and surgery instruments. Owing to its high corrosion resistance, lightness, tensile strength and ease of forging, rolling and stamping titanium is used in a great variety of fields. Titanium alloys are applied in mechanical engineering, medical and chemical areas.
Alloying elements are added to achieve certain properties in the material. Alloying elements are added in lower percentages (less than 5 %) to increase strength or hardenability, or in larger percentages (over 5 %) to achieve special properties, such as corrosion resistance or extreme temperature stability.
Manganese, silicon, or aluminium are added during the steelmaking process to remote dissolved oxygen from the melt. Manganese, silicon, nickel, and copper are added to increase strength by forming solid solutions in ferrite. Chromium, vanadium, molybdenum, and tungsten increase strength by forming second-phase carbides. Nickel and copper improve corrosion resistance in small quantities. Molybdenum helps to resist embrittlement. Zirconium, cerium, and calcium increase toughness by controlling the shape of inclusions. Manganese sulfide, lead, bismuth, selenium, and tellurium increase machinability. All mentioned alloying elements can form either compounds or carbides.
* eutectoid – эвтекетоид (сплав, точка плавления которого выше точек плавления входящих в его состав компонентов).
** eutectic – эвтектический (сплав, точка плавления которого ниже).
Exercise 3. Complete the sentences:
1. The term “alloy” determines…
2. The main alloying element in ferrous metals is …
3. The ferrous alloys with less than 2,14 % С are termed as…
4. Ferrous and non-ferrous alloys are widely used in …
5. Aluminium alloys are mainly used because of …
6. Aluminium alloys possess desirable property of …
7. Zink alloys have advantages over…
8. Titanium alloys are applied in …
9. Alloying elements are added to some metals in order to…
10. All alloying elements can form …
Exercise 4. Insert the proper words into the sentences:
1. The term (сплав) determines material (содержащий) more than one element.
2. (Углерод) is the main (легирующий) element in (черный) metals.
3. Each metal (обладать) distinct (свойствами).
4. Steels are alloys of (железо) and (углерод) with other (легирующими) elements.
5. Gray (чугун) is weak and (хрупкий).
6. (Ковкий чугун) possesses high amount of (тягучесть).
7. (Недостатком) of aluminium alloys is their low (температура плавления).
8. Aluminium alloys are used where (требуется легкий вес).
9. (Медные сплавы) form such metals, as (латунь) and (бронза).
10. Titanium is inert in (биологической среде) and is widely used in (медицина).
Exercise 5. Find in the text the sentences that correspond to the following statements:
1. The amount of carbon in metals may differ.
2. Different amount of carbon form quite different alloys.
3. Each metal has its own properties depending on the alloying elements.
4. Different amount of carbon affects the types of steels.
5. Cast irons can be divided into several groups.
6. Aluminium alloys show various useful features.
7. In engineering there is a great variety of non-ferrous alloys.
8. The aluminium alloys can have some other alloying elements and are useful in particular technical conditions.
9. Titanium is used in different fields due to its numerous remarkable properties.
10. Alloying elements in certain proportions improve the properties of metals.
Exercise 6. Translate into English:
1. Термин «сплав» означает материал, состоящий более чем из одного элемента.
2. Основным легирующим элементом черных металлов является углерод.
3. В зависимости от процентного содержания углерода сплавы делятся на стали и чугуны.
4. Существуют не только черные, но и цветные сплавы.
5. Как черные, так и цветные металлы обладают эластичностью, тягучестью, ковкостью и прочностью.
6. Такие металлы, как медь, магний, никель и цинк придают сплавам особые свойства.
7. Титан обладает уникальными качествами и широко применяется в медицине.
8. Титан проявляет высокую устойчивость к коррозии, легкость, прочность на растяжение, но главным является инертность по отношению к биологической среде.
9. Легирующие элементы добавляются к другим металлам, чтобы создать новые, улучшенные свойства материала.
10. Известными легирующими элементами являются силикон, хром, свинец, висмут, селен и теллур.
Speaking:
Exercise 7. Give the summary of the text, using key vocabulary and tell about:
a) the concept of alloy;
b) ferrous and non-ferrous metals and alloys;
c) importance of metals and alloys in engineering;
d) the aim of melting various elements with metals;
e) the properties of alloys;
f) the spheres of application of some metals and alloys.
Checklist for Section III:
1. How are compound conjunctions translated into Russian?
2. What is conversion?
3. What are the widely used metals for forming alloys?
4. What properties do metals give the alloys?
Section IV. Steels
Grammar: Gerund.
Word-formation: Suffix -ity.
Speaking: Types and properties of steels.
Practise the reading of the words:
| enough | [I′nΛf] |
| microstructure | [/maIkrə′strΛktòə] |
| typical | [tIpIkəl] |
| require | [rI′kwaIə] |
| pressure | [′preòə] |
| surgical | [′sə:dჳIkəl] |
Learn the pronunciation and meaning of the words:
| cost-effective | затратный, расходный | |
| treatment | обработка | |
| austenitize | [/ɔ:stənItaIz] | аустенитизировать (создавать немагнитный твердый раствор углерода) |
| quench | [kwentò] | закаливать (металл) |
| temper | закаливать с последующим отпуском | |
| hacksaw blade | ножовочное полотно | |
| plain carbon steel | низкоуглеродистая сталь | |
| alloy steel | легированная сталь | |
| high-strength low alloy steel | высокопрочная низколегированная сталь | |
| pressure vessel | сосуд высокого давления | |
| stainless steel | нержавеющая сталь | |
| cutlery | [′kΛtlərI] | ножевые изделия |
| susceptibility | [sə/septə′bIlItI] | подверженность, чувствительность, восприимчивость |
| punch | штамп, пуансон, пробойник | |
| stamping die | [daI] | штамповочная пресс-форма |
| suitability | [/sju:tə′bIlItI] | пригодность |
| tap | метчик (для нарезки резьбы) | |
| milling cutter | фреза | |
| tool bit | вставной резец | |
| gear cutter | зуборезная фреза |
Vocabulary development: word building:
Exercise 1. Translate the original and derivative words, using a dictionary and create several new words by adding suffixes:
| verb | noun (abstract) | noun (personal) | adjective |
| to improve | improvement | improver | допускающий улуч-шение |
| to divide | делимость division divisor | divider | dividual divisible divisional |
| to quench | quencher quenching | - | незакаленный |
| to temper | temper | - | - |
| - | susceptibility | - | susceptible восприимчивый |
| подводить пригождаться | suit suitability | suitor | - |
Exercise 2. Translate the following word combinations with Gerund:
alloying material, alloying metal, quenching, alloying additions, tempering, alloying elements, hardening tool steel, alloying constituent, stamping die, metal cutting tool, cutting edge, tool steels are used for making tools, impact loading, milling cutter.
Text
Read the text giving classification and properties of steels:
Steels
Steels are widely known and mostly used materials in comparison with any other ones. Steels are alloys of iron and carbon with other alloying elements. Carbon is the most cost-effective alloying material for iron, but various other alloying elements are used – manganese, chromium, vanadium and tungsten. The latter are necessary to improve many properties of steels – corrosion resistance, strength, formability and others. Mechanical properties of steels greatly depend on carbon content. According to this indication the steels are basically divided into three kinds: low carbon, medium carbon and high carbon.
Carbon is limited in low carbon steels and not enough to strengthen them by heat treatment, but only cold one. The microstructure of low carbon steels consists of ferrite and pearlite, they are relatively soft, ductile and possess high toughness. They are weldable and easily machined. The typical applications of these steels are: structural shapes, tin cans, automobile body components, building, etc.
Medium carbon steels are stronger than low carbon steels, although are less ductile, but their strength can be improved by heat treatment. Usual heat treatment includes austenitizing, quenching and tempering. Such alloying additions as nickel, chrome and molybdenum improve their hardness. The sphere of application of medium carbon steels is railway tracks and wheels, gears, the machine parts which require strength and toughness.
High carbon steels are the strongest and hardest and therefore their ductility is very limited. Their hardness is achieved with addition of such alloying elements as chrome, vanadium, molybdenum and bismuth. These steels possess very high wear resistance and are used for sharp edged tool application: knives, razors, hacksaw blades, etc.
The other parameter for classification of steels is amount of alloying addition. According to this criterion the steels are of two kinds: plain carbon steels and alloy steels. A special group of ferrous alloys with considerable amount of alloying additions is known as HSLA (high-strength low alloy steels). Common alloying elements are copper, vanadium, nickel, bismuth, chrome, molybdenum and others. These alloys are ductile, formable and applied in support columns, bridges, and pressure vessels.
Another widely used kind of steel is stainless steels. They are highly resistant to corrosion and are called rustless or stainless. Highly corrosion resistance is achieved by addition of special alloying elements, especially a minimum of 12 % chrome along with nickel and molybdenum. The typical application of such steels is cutlery, razor blades, surgical tools, etc. Besides, in engineering it is accepted to differ some other kinds of steels: structural steel, carbon steel, alloy steel, tool steel, self (air) hardening tool steel, heat-resisting steel, high speed steel.
Structural steel is widely applied because of its strength, toughness, workability, but it has two drawbacks – heavy weight and susceptibility to rust.
Carbon steel is steel where the main alloying constituent is carbon, and when no minimum content is required for chromium, cobalt, niobium, molybdenum, nickel, titanium, tungsten, vanadium or zirconium. High carbon steel is very strong and used for springs, high-strength wires, knives, axles, punches, stamping dies, metal cutting tools, etc.
Alloy steel is steel alloyed with other elements in amounts of between 1 and 50 % by weight to improve its mechanical properties. These steels have greater strength, hardness, hot hardness, wear resistance, hardenability and toughness compared to carbon steel. However, they require heat treatment in order to achieve such properties. Common alloying elements are molybdenum, manganese, nickel, chromium, vanadium, silicon and boron. Such steels are used where high corrosion resistance in certain environmental conditions is needed.
Tool steel refers to a variety of carbon and alloy steels that are particularly well-suited to be made into tools. Their suitability comes from their hardness, resistance to abrasion, ability to hold a cutting edge and resistance to deformation at elevated temperatures. Tool steels are generally used in a heat-treated state for making tools which have to withstand impact loading.
High speed steel (HSS) is basically iron – carbon alloy in which various elements, principally tungsten and molybdenum, have been added to improve their hardness, toughness, heat resistance and wear resistance. High speed steels are usually used in the manufacture of various cutting tools: drills, taps, milling cutters, tool bits, gear cutters, saw blades, punches and dies. High speed steel tools maintain their edge longer than carbon steel ones.
Exercise 3. Complete the sentences:
1. Mechanical properties of steels depend on…
2. Depending on carbon the steels are divided into…
3. Steels are alloys of…
4. The microstructure of low carbon steels consists of …
5. The applications of low carbon steels are…
6. The strength of medium carbon steels can be improved by …
7. The sphere of application of medium carbon steels is…
8. The hardness of high carbon steels is achieved with…
9. One of the parameters for classification of steels is the amount of…
10. Stainless steels are highly resistant to…
Exercise 4. Insert the proper words into the sentences:
1. (Углерод) is the most (затратный) (легирующий материал).
2. Alloying elements are necessary (чтобы улучшать) (свойства) of steels.
3. Steels (широко известные) материалы.
4. Carbon steels are (свариваемые) and (легко обрабатываемые на станках).
5. Medium carbon steels (прочнее) than low carbon steels, but (менее ковкие).
6. (Прочность) of high carbon steels (достигается) with addition of some (легирующих металлов).
7. High carbon steels (обладают) very high (износоустойчивостью).
8. The steels are divided into (низко углеродистую) and (легированную).
9. High-strength low alloy steels have (значительное количество) of (легирующих добавок).
10. (Нержавеющая сталь) is widely used for (хирургических инструментов).
Exercise 5. Find in the text the sentences that correspond to the following statements:
1. Carbon is the main constituent affecting the mechanical properties of steel.
2. Depending on carbon content the steels are divided into three types.
3. The main purpose of using alloying elements is to make steels strong and corrosion resistant.
4. The amount of carbon influences the mechanical characteristics of steels.
5. Carbon is the most expensive ingredient comparing with others.
6. The amount of alloying additions is one of the parameters that change the type of steels.
7. In machine building there are various types of steels.
8. Structural steel besides its advantages has also some drawbacks.
9. Alloy steel possesses higher characteristics and is used in the most difficult environmental conditions.
10. A lot of tools which need special strength are made of high speed steel.
Exercise 6. Translate into English:
1. Стали – наиболее используемые материалы в машиностроении.
2. Сталь – это сплав железа и углерода.
3. Легирующими элементами стали являются многие металлы: магний, хром, ванадий, вольфрам, никель, алюминий и другие.
4. Добавки к железу меняют свойства сплавов.
5. Легирующие элементы нужны, чтобы улучшить свойства сталей.
6. Стали должны обладать такими свойствами, как прочность, устойчивость к коррозии, ковкость, обрабатываемость.
7. В технике существуют различные сорта сталей: нержавеющая, инструментальная, теплостойкая, высокопрочная, углеродистая.
8. Свойства стали зависят как от количества углерода, так и от количества добавочных элементов.
9. Одни стали должны выдерживать высокие температуры, другие – высокое давление.
10. Для различных строительных сооружений, инструментов и деталей машин используются соответствующие сорта сталей.
Speaking:
Exercise 7. Give the summary of the text, using key vocabulary and tell about:
a) what is steel;
b) the role of carbon in steels;
c) the necessary properties of steels;
d) the necessity of using alloying elements;
e) metals serving as alloying materials;
f) the kinds of steels;
g) the sphere of application of steels.
Checklist for Section IV:
1. What are the functions of Gerund and its difference from Participle I?
2. What is the meaning of the suffix - ity?
3. What properties should steels possess?
4. What are the types of steels and where are they applied?