Other Methods of Iron Refining

Although almost all the iron and steel manufactured in the world is made from pig iron produced by the blast-furnace process, other methods of iron refining are possible and have been practiced to a limited extent. One such method is the so-called direct method of making iron and steel from ore, without making pig iron. In this process iron ore and coke are mixed in a revolving kiln and heated to a temperature of about 950° C. Carbon monoxide is given off from the heated coke just as in the blast furnace and reduces the oxides of the ore to metallic iron. The secondary reactions that occur in a blast furnace, however, do not occur, and the kiln produces so-called sponge iron of much higher purity than pig iron. Virtually pure iron is also produced by means of electrolysis, by passing an electric current through a solution of ferrous chloride. Neither the direct nor the electrolytic processes has yet achieved any great commercial significance.

 

 

Text C

Basic Oxygen Process

The oldest process for making steel in large quantities, the Bessemer process, made use of a tall, pear-shaped furnace, called a Bessemer converter that could be tilted sideways for charging and pouring. Great quantities of air were blown through the molten metal; its oxygen united chemically with the impurities and carried them off.

In the basic oxygen process, steel is also refined in a pear-shaped furnace that tilts sideways for charging and pouring. Air, however, has been replaced by a high-pressure stream of nearly pure oxygen. After the furnace has been charged and turned upright, an oxygen lance is lowered into it. The water-cooled tip of the lance is usually about 2 m above the charge although this distance can be varied according to requirements. Thousands of cubic meters of oxygen are blown into the furnace at supersonic speed. The oxygen combines with carbon and other unwanted elements and starts a high-temperature churning reaction that rapidly burns out impurities from the pig iron and converts it into steel. The refining process takes 50 min or less; approximately 275 metric tons of steel can be made in an hour.

Exercise 1

Ответьте на следующие вопросы:

 

1. What is the oldest process for making steel in large quantities?

2. Can you describe the Bessemer converter?

3. What is the function of the air Bessemer process?

4. Has air been replaced in basic oxygen process by hydrogen or other material?

5. What is lowered into the furnace after the furnace is charged and ready to start operation?

6. What is the approximate distance of the water-cooled tip of the lance above the charge?

7. Does the refining process take more than two hour to finish the Bessemer process?

8. What volume of steel can be made in an hour time in Bessemer converter?

Exercise 2

Заполните пропуски недостающими по смыслу словами, используя текст:

 

1. The Bessemer process is the oldest process for making … in large quantities.

2. A tall, pear-shaped furnace is called a Bessemer ….

3. The Bessemer converter can be … sideways for charging and …

4. Great quantities of … have to be blown through the molten metal during the Bessemer process.

5. In Bessemer process oxygen unites chemically with the … and carries them off.

6. In the basic … … steel is also refined in a pear-shaped furnace that tilts sideways for charging and pouring.

7. After the furnace is charged and turned upright, an oxygen … is lowered into it.

8. Thousands of cubic meters of … are blown into the furnace at supersonic speed.

9. The oxygen combines with … and other unwanted elements and starts a high-temperature churning reaction.

Exercise 3

Соответствуют ли данные предложения содержанию текста:

1. The latest process for making steel in large quantities is called the Bessemer process.

2. Very limited quantities of air are blown through the molten metal in the Bessemer process.

3. In the basic oxygen process, steel is also rolled into sheets.

4. The oil-cooled tip of the lance is usually about 2 m above the charge.

5. Thousands of cubic meters of hydrogen are blown into the furnace at normal speed.

6. In the Bessemer process the oxygen combines with carbon and other unwanted elements.

7. The refining process in Bessemer converter takes 50 min or less.

8. Approximately 1275 metric tons of steel can be made in an hour.

Exercise 4

Используя текст, составьте высказывания с данными словами и выражениями:

charging and pouring - basic oxygen process - high-pressure stream - pure oxygen – to turn upright - supersonic speed - unwanted elements - to burn out impurities - refining process.

Exercise 5

Кратко передайте содержание каждого абзаца.

 

Exercise 6

Выделите пять основных идей текста.

 

Exercise 7

Составьте предложения, используя данные выражения:

To carry out impurities – to blow air through –to tilt sideways - molten metal – to unite chemically - basic oxygen process – to turn upright – to vary according to requirements - supersonic speed – to combine with smth. – to burn out - refining process.

 

Exercise 8

Переведите на русский язык следующие предложения:

1. The Bessemer process is the first method discovered for mass-producing steel.

2. Sir Henry Bessemer of England began experiments aimed at developing a revolutionary means of removing impurities from pig iron by an air blast.

3. The scientist found that adding an alloy of carbon, manganese, and iron after the air-blowing was complete restored the carbon content of the steel while neutralizing the effect of remaining impurities, notably sulfur.

4. The Bessemer converter is a cylindrical steel pot approximately 6 m. high, originally lined with a siliceous refractory.

5. The original Bessemer converter was not effective in removing the phosphorus present in sizable amounts in most British and European iron ore.

6. Bessemer converter could be tilted sideways for charging and pouring.

7. Great quantities of air were blown through the molten metal; its oxygen united chemically with the impurities and carried them off.

 

Exercise 9

Переведите на английский язык:

1. Cамым старым методом плавки стали в больших объемах является Бессемеровский метод.

2. Огромное количество воздуха продувается через расплавленный металл при Бессемеровском методе плавки

3. В процессе плавки кислород химически соединяется с углеродом и примесями и выводит их из металла.

4. В процессе развития конвертерного производства стали, воздух был заменен кислородом, подаваемый в печь, под высоким давлением.

5. Загрузка и выгрузка печи осуществляется путем ее наклона в сторону.

6. Охлаждаемый водой наконечник трубки – обычно находится на высоте приблизительно 2 метров выше уровня загрузки.

7. В кислородно-конвертерном процессе производства стали, тысячи кубических метров кислорода вдуваются в печь на сверхзвуковой скорости.

8. В кислородно-конвертерном процессе, кислород соединяется с углеродом и другими нежелательными примесями, быстро сжигает примеси чугуна и конвертирует его в сталь.

Exercise 10

Текст на самостоятельный перевод:

Open-Hearth Process

Essentially the production of steel from pig iron by any process consists of burning out the excess carbon and other impurities present in the iron. One difficulty in the manufacture of steel is its high melting point, about 1370° C, which prevents the use of ordinary fuels and furnaces. To overcome this difficulty the open-hearth furnace was developed; this furnace can be operated at a high temperature by regenerative preheating of the fuel gas and air used for combustion in the furnace. In regenerative preheating, the exhaust gases from the furnace are drawn through one of a series of chambers containing a mass of brickwork and give up most of their heat to the bricks. Then the flow through the furnace is reversed and the fuel and air pass through the heated chambers and are warmed by the bricks. Through this method open-hearth furnaces can reach temperatures as high as 1650° C. The furnace itself consists typically of a flat, rectangular brick hearth about 6 m by 10 m, which is roofed over at a height of about 2.5 m. In front of the hearth a series of doors opens out onto a working floor in front of the hearth. The entire hearth and working floor are one story above ground level, and the heat-regenerating chambers of the furnace take up the space under the hearth. A furnace of this size produces about 100 metric tons of steel every 11 hr. The furnace is charged with a mixture of pig iron (either molten or cold), scrap steel, and iron ore that provides additional oxygen. Limestone is added for flux and fluorspar to make the slag more fluid. The proportions of the charge vary within wide limits, but a typical charge might consist of 56, 750 kg of scrap steel, 11, 350 kg of cold pig iron, 45, 400 kg of molten pig iron, 11, 800 kg of limestone, 900 kg of iron ore, and 230 kg of fluorspar. After the furnace has been charged, the furnace is lighted and the flames play back and forth over the hearth as their direction is reversed by the operator to provide heat regeneration. Chemically the action of the open-hearth furnace consists of lowering the carbon content of the charge by oxidization and of removing such impurities as silicon, phosphorus, manganese, and sulfur, which combine with the limestone to form slag. These reactions take place while the metal in the furnace is at melting heat, and the furnace is held between 1540° and 1650° C for many hours until the molten metal has the desired carbon content. Experienced open-hearth operators can often judge the carbon content of the metal by its appearance, but the melt is usually tested by withdrawing a small amount of metal from the furnace, cooling it, and subjecting it to physical examination or chemical analysis. When the carbon content of the melt reaches the desired level, the furnace is tapped through a hole at the rear. The molten steel then flows through a short trough to a large ladle set below the furnace at ground level. From the ladle the steel is poured into cast-iron molds that form ingots usually about 1.5 m long and 48 cm square. These ingots, the raw material for all forms of fabricated steel, weigh approximately 2.25 metric tons in this size. Recently, methods have been put into practice for the continuous processing of steel without first having to go through the process of casting ingots.

Text D

Finishing Processes

 

Steel is marketed in a wide variety of sizes and shapes, such as rods, pipes, railroad rails, tees, channels, and I-beams. These shapes are produced at steel mills by rolling and otherwise forming heated ingots to the required shape. The working of steel also improves the quality of the steel by refining its crystalline structure and making the metal tougher.

The basic process of working steel is known as hot rolling. In hot rolling the cast ingot is first heated to bright-red heat in a furnace called a soaking pit and is then passed between a series of pairs of metal rollers that squeeze it to the desired size and shape. The distance between the rollers diminishes for each successive pair as the steel is elongated and reduced in thickness.

The first pair of rollers through which the ingot passes is commonly called the blooming mill, and the square billets of steel that the ingot produces are known as blooms. From the blooming mill, the steel is passed on to roughing mills and finally to finishing mills that reduce it to the correct cross section. The rollers of mills used to produce railroad rails and such structural shapes as I-beams, H-beams, and angles are grooved to give the required shape.

Modern manufacturing requires a large amount of thin sheet steel. Continuous mills roll steel strips and sheets in widths of up to 2.4 m. Such mills process thin sheet steel rapidly, before it cools and becomes unworkable. A slab of hot steel over 11 cm thick is fed through a series of rollers which reduce it progressively in thickness to 0.127 cm and increase its length from 4 m to 370 m. Continuous mills are equipped with a number of accessory devices including edging rollers, descaling devices, and devices for coiling the sheet automatically when it reaches the end of the mill. The edging rollers are sets of vertical rolls set opposite each other at either side of the sheet to ensure that the width of the sheet is maintained. Descaling apparatus removes the scale that forms on the surface of the sheet by knocking it off mechanically, loosening it by means of an air blast, or bending the sheet sharply at some point in its travel. The completed coils of sheet are dropped on a conveyor and carried away to be annealed and cut into individual sheets. A more efficient way to produce thin sheet steel is to feed thinner slabs through the rollers. Using conventional casting methods, ingots must still be passed through a blooming mill in order to produce slabs thin enough to enter a continuous mill.

By devising a continuous casting system that produces an endless steel slab less than 5 cm thick, German engineers have eliminated any need for blooming and roughing mills. In 1989, a steel mill in Indiana became the first outside Europe to adopt this new system.

Words and expressions

tee - тавровая балка; тройник; Т-образный

элемент

channel - швеллер

I-beam - двутавровая балка

ingot - слиток

soaking pit - томильный, нагревательный колодец

blooming mill - прокатный стан блюминг

continuous mill - непрерывный стан

to anneal - отжигать, обжигать

Exercise 1

Ответьте на следующие вопросы:

 

1. In what main shapes steel is generally marketed?

2. What are the main methods of steel shapes production at steel mills?

3. Does the working of steel improve the quality of steel and how?

4. What process of working of steel is considered to be the basic?

5. What is passed between a series of pairs of metal rollers during the hot rolling process?

6. How do we call the first pair of rollers through which the ingot passes in hot rolling process?

7. What structural shapes are rolled through specially grooved rollers?

8. What type of steel product is widely required by modern manufacturing enterprises?

9. What is the main equipment of modern rolling mills?

10. Who were to eliminate any need for blooming and roughing mills?

Exercise 2

Соответствуют ли данные предложения содержанию текста:

1. Pig Iron is marketed in a wide variety of sizes and shapes, such as rods, pipes, railroad rails, tees, channels, and I-beams.

2. Steel shapes are produced at Blast furnaces by rolling and otherwise forming heated ingots to the required shape.

3. The working of steel improves the quality of the steel.

4. The basic process of working steel is known as cold rolling.

5. In hot rolling the steel is elongated and reduced in thickness.

6. The first pair of rollers through which the ingot passes is commonly called the section mill.

7. From the blooming mill, the steel goes to roughing mills and finally to finishing mills.

8. The rollers of sheet mills are grooved to give the required shape.

9. Modern manufacturing requires a large amount of thin sheet steel.

10. A more efficient way to produce thin sheet steel is to feed thicker slabs through the rollers.

11. A continuous casting system produces an endless steel slab less than 5 cm thick.

 

Exercise 3

Заполните пропуски недостающими по смыслу словами, используя текст:

1. Such steel shapes as rods, pipes, railroad rails, tees, channels, and I-beams are produced at … ….

2. The basic process of working steel is known as … rolling.

3. In hot rolling the cast ingot is first heated in a furnace called a … pit.

4. The first pair of rollers through which the ingot passes is called the … mill.

5. The rollers of mills used to structural shapes as I-beams, H-beams, and angles are … to give the required shape.

6. Continuous mills roll steel strips … before it cools and becomes unworkable.

7. A more efficient way to produce thin sheet steel is to feed … slabs through the rollers.

8. A continuous casting system eliminated any need for … and … mills.

Exercise 4

Используя текст, составьте высказывания с данными словами и выражениями:

Sizes and shapes – required shape - working of steel - hot rolling - cast ingot - desired size - pair of rollers - correct cross section – to be grooved - to become unworkable – to be equipped with - accessory device – to cut into individual sheets- conventional casting methods – to eliminate any need for - to adopt a new system.

 

Exercise 5

Кратко передайте содержание каждого абзаца.

 

Exercise 6

Выделите пять основных идей текста.

 

Exercise 7

Составьте предложения, используя данные выражения:

· Ingot (слиток; болванка); bled ingot (вытекающий слиток, слиток с пустотами); burnt ingot (перегретый слиток); capped ingot (успокоенный в изложнице слиток); forging ingot (поковочный, кузнечный слиток); rimming ingot (слиток кипящей стали); slab ingot (листовой слиток); ingoted (разлитый с литки).

· Shape (профиль, форма); first shape (первоначальная форма); intricate shape (сложный или фигурный профиль); rolled shape (катаный профиль); special shape (специальный шаблон, специальный профиль).

· Mill (прокатный стан); roughing mill (обжимной стан, черновая клеть); billet mill (заготовочный стан); blooming mill (обжимной стан, блюминг); cold rolling mill (стан холодной прокатки); cold-strip mill (листовой стан холодной прокатки); continuous rolling mill (непрерывный прокатный стан); edging mill (стан с валками для обжатия кромок); finishing mill (чистовой, отделочный прокатный стан); heavy-plate rolling mill (толстолистовой прокатный стан); merchant mill (среднесортный прокатный стан); pipe mill (трубопрокатный стан); plate mill (толстолистовой стан); rod mill (проволочнопрокатный стан); sheet mill (тонколистовой прокатный стан); slab mill (слябинг, стан для прокатки слябов); universal mill (универсальный прокатный стан);

· Air blast (воздушное дутье); enriched blast (обогащенное дутье); high temperature blast (высокотемпературное дутье); hot blast (горячее дутье); oxygen-enriched blast (дутье, обогащенное кислородом); oxygen-steam blast (парокислородное дутье); sand-blast (струя воздуха с песком).

 

Exercise 8

Переведите на русский язык следующие предложения:

 

1. Shapes are long products with irregular cross sections, such as beams, channels, angles, and rails.

2. The blooms are received, either cold or hot, directly from the blooming mill or continuous caster.

3. There are usually three to five stands arranged in various ways, each taking one to five passes.

4. Only one pass is made through the finishing stand, which controls the final dimension and surface.

5. Mills that produce medium and small shapes often have stands in tandem arrangement.

6. Rolling temperatures are carefully controlled for metallurgical reasons.

7. Heavy-walled, wide-flange I-beams are sometimes heat-treated in-line by computer-controlled water quenching and by tempering with their own retained heat.

8. The heads of rails are often heat-treated in-line to improve wear and impact resistance.

9. Rails are also slow-cooled under an insulated cover, directly after rolling, for at least 10 hours to diffuse hydrogen out of the steel.

10. After rolling, a hot saw cuts the shapes into lengths that can be handled by the cooling bed.

11. Each shop conducts large-size finishing operations such as straightening, cold-cutting to ordered length, marking, and inspection.

12. Tubular products are manufactured according to two basic technologies. One is the welding of tubes from strip, and the other is the production of seamless tube from rounds or blooms.

Exercise 9

Переведите на английский язык:

1. Металлургические заводы производят сталь в широком разнообразии размеров и профилей.

2. Наша компания успешно торгует на рынке такими продуктами как: арматура, трубы, ж/д рельсы, тавровые балки, швеллеры, и двутавровые балки.

3. Обработка стали на прокатных станах улучшает ее качество, очищает ее кристаллическую структуру и делает метал более жестким.

4. В горячем прокатном производстве литой слиток в горячем виде подается на блюминг.

5. Расстояние между валами на прокатном стане уменьшается для каждой последовательной клети.

6. Первая пара валов, через которые проходит слиток называется блюмингом.

7. От блюминга, сталь передается на обжимной стан и наконец на чистовой прокатный стан.

8. Непрерывные станы прокатывают стальные полосы и листы в ширину до 2.4 м.

9. Непрерывные прокатные станы оборудованы большим количеством дополнительного оборудования.

10. Для удаления окалины с поверхности листа используется специальный аппарат удаления окалины.

11. Применение системы непрерывной разливки исключило использование блюмингов.

Exercise 10

Текст на самостоятельный перевод:

Pipe

Cheaper grades of pipe are shaped by bending a flat strip, or skelp, of hot steel into cylindrical form and welding the edges to complete the pipe. For the smaller sizes of pipe, the edges of the skelp are usually overlapped and passed between a pair of rollers curved to correspond with the outside diameter of the pipe. The pressure on the rollers is great enough to weld the edges together. Seamless pipe or tubing is made from solid rods by passing them between a pair of inclined rollers that have a pointed metal bar, or mandrel, set between them in such a way that it pierces the rods and forms the inside diameter of the pipe at the same time that the rollers are forming the outside diameter.

Tin Plate

By far the most important coated product of the steel mill is tin plate for the manufacture of containers. The “tin” can is actually more than 99 percent steel. In some mills steel sheets that have been hot-rolled and then cold-rolled are coated by passing them through a bath of molten tin. The most common method of coating is by the electrolytic process. Sheet steel is slowly unrolled from its coil and passed through a chemical solution. Meanwhile, a current of electricity is passing through a piece of pure tin into the same solution, causing the tin to dissolve slowly and to be deposited on the steel. In electrolytic processing, less than half a kilogram of tin will coat more than 18.6 sq m (more than 200 sq ft) of steel. For the product known as thin tin, sheet and strip are given a second cold rolling before being coated with tin, a treatment that makes the steel plate extra tough as well as extra thin. Cans made of thin tin are about as strong as ordinary tin cans, yet they contain less steel, with a resultant saving in weight and cost. Lightweight packaging containers are also being made of tin-plated steel foil that has been laminated to paper or cardboard.

Wrought Iron

The process of making the tough, malleable alloy known as wrought iron differs markedly from other forms of steel making. Because this process, known as puddling, required a great deal of hand labor, production of wrought iron in tonnage quantities was impossible. The development of new processes using Bessemer converters and open-hearth furnaces allowed the production of larger quantities of wrought iron.

Wrought iron is no longer produced commercially, however, because it can be effectively replaced in nearly all applications by low-carbon steel, which is less expensive to produce and is typically of more uniform quality than wrought iron.

The puddling furnace used in the older process has a low, arched roof and a depressed hearth on which the crude metal lies, separated by a wall from the combustion chamber in which bituminous coal is burned. The flame in the combustion chamber surmounts the wall, strikes the arched roof, and “reverberates” upon the contents of the hearth. After the furnace is lit and has become moderately heated, the puddler, or furnace operator, “fettles” it by plastering the hearth and walls with a paste of iron oxide, usually hematite ore. The furnace is then charged with about 270 kg of pig iron and the door is closed. After about 30 min the iron is melted and the puddler adds more iron oxide or mill scale to the charge, working the oxide into the iron with a bent iron bar called a raddle. The silicon and most of the manganese in the iron are oxidized and some sulfur and phosphorus are eliminated. The temperature of the furnace is then raised slightly, and the carbon starts to burn out as carbon-oxide gases. As the gas is evolved the slag puffs up and the level of the charge rises. As the carbon is burned away the melting temperature of the alloy increases and the charge becomes more and more pasty, and finally the bath drops to its former level. As the iron increases in purity, the puddler stirs the charge with the raddle to ensure uniform composition and proper cohesion of the particles. The resulting pasty, spongelike mass is separated into lumps, called balls, of about 80 to 90 kg each. The balls are withdrawn from the furnace with tongs and are placed directly in a squeezer, a machine in which the greater part of the intermingled siliceous slag is expelled from the ball and the grains of pure iron are thoroughly welded together. The iron is then cut into flat pieces that are piled on one another, heated to welding temperature, and then rolled into a single piece. This rolling process is sometimes repeated to improve the quality of the product.

The modern technique of making wrought iron uses molten iron from a Bessemer converter and molten slag, which is usually prepared by melting iron ore, mill scale, and sand in an open-hearth furnace. The molten slag is maintained in a ladle at a temperature several hundred degrees below the temperature of the molten iron. When the molten iron, which carries a large amount of gas in solution, is poured into the ladle containing the molten slag, the metal solidifies almost instantly, releasing the dissolved gas. The force exerted by the gas shatters the metal into minute particles that are heavier than the slag and that accumulate in the bottom of the ladle, agglomerating into a spongy mass similar to the balls produced in a puddling furnace. After the slag has been poured off the top of the ladle, the ball of iron is removed and squeezed and rolled like the product of the puddling furnace.

Classifications of Steel

Steels are grouped into five main classifications.

Carbon Steels

More than 90 percent of all steels are carbon steels. They contain varying amounts of carbon and not more than 1.65 percent manganese, 0.60 percent silicon, and 0.60 percent copper. Machines, automobile bodies, most structural steel for buildings, ship hulls, bedsprings, and bobby pins are among the products made of carbon steels.

Alloy Steels

These steels have a specified composition, containing certain percentages of vanadium, molybdenum, or other elements, as well as larger amounts of manganese, silicon, and copper than do the regular carbon steels. Automobile gears and axles, roller skates, and carving knives are some of the many things that are made of alloy steels.

High-Strength Low-Alloy Steels

Called HSLA steels, they are the newest of the five chief families of steels. They cost less than the regular alloy steels because they contain only small amounts of the expensive alloying elements. They have been specially processed, however, to have much more strength than carbon steels of the same weight. For example, freight cars made of HSLA steels can carry larger loads because their walls are thinner than would be necessary with carbon steel of equal strength; also, because an HSLA freight car is lighter in weight than the ordinary car, it is less of a load for the locomotive to pull. Numerous buildings are now being constructed with frameworks of HSLA steels. Girders can be made thinner without sacrificing their strength, and additional space is left for offices and apartments.

Stainless Steels

Stainless steels contain chromium, nickel, and other alloying elements that keep them bright and rust resistant in spite of moisture or the action of corrosive acids and gases. Some stainless steels are very hard; some have unusual strength and will retain that strength for long periods at extremely high and low temperatures. Because of their shining surfaces architects often use them for decorative purposes. Stainless steels are used for the pipes and tanks of petroleum refineries and chemical plants, for jet planes, and for space capsules. Surgical instruments and equipment are made from these steels, and they are also used to patch or replace broken bones because the steels can withstand the action of body fluids. In kitchens and in plants where food is prepared, handling equipment is often made of stainless steel because it does not taint the food and can be easily cleaned.

Tool Steels

These steels are fabricated into many types of tools or into the cutting and shaping parts of power-driven machinery for various manufacturing operations. They contain tungsten, molybdenum, and other alloying elements that give them extra strength, hardness, and resistance to wear.

Structure of Steel

The physical properties of various types of steel and of any given steel alloy at varying temperatures depend primarily on the amount of carbon present and on how it is distributed in the iron. Before heat treatment most steels are a mixture of three substances: ferrite, pearlite, and cementite. Ferrite is iron containing small amounts of carbon and other elements in solution and is soft and ductile. Cementite, a compound of iron containing about 7 percent carbon, is extremely brittle and hard. Pearlite is an intimate mixture of ferrite and cementite having a specific composition and characteristic structure, and physical characteristics intermediate between its two constituents. The toughness and hardness of a steel that is not heat treated depend on the proportions of these three ingredients. As the carbon content of a steel increases, the amount of ferrite present decreases and the amount of pearlite increases until, when the steel has 0.8 percent of carbon, it is entirely composed of pearlite. Steel with still more carbon is a mixture of pearlite and cementite. Raising the temperature of steel changes ferrite and pearlite to an allotropic form of iron-carbon alloy known as austenite, which has the property of dissolving all the free carbon present in the metal. If the steel is cooled slowly the austenite reverts to ferrite and pearlite, but if cooling is sudden, the austenite is “frozen” or changes to martensite, which is an extremely hard allotropic modification that resembles ferrite but contains carbon in solid solution.

Heat Treatment of Steel

The basic process of hardening steel by heat treatment consists of heating the metal to a temperature at which austenite is formed, usually about 760° to 870° C and then cooling, or quenching, it rapidly in water or oil. Such hardening treatments, which form martensite, set up large internal strains in the metal, and these are relieved by tempering, or annealing, which consists of reheating the steel to a lower temperature. Tempering results in a decrease in hardness and strength and an increase in ductility and toughness.

The primary purpose of the heat-treating process is to control the amount, size, shape, and distribution of the cementite particles in the ferrite, which in turn determines the physical properties of the steel.

Many variations of the basic process are practiced. Metallurgists have discovered that the change from austenite to martensite occurs during the latter part of the cooling period and that this change is accompanied by a change in volume that may crack the metal if the cooling is too swift. Three comparatively new processes have been developed to avoid cracking. In time-quenching the steel is withdrawn from the quenching bath when it has reached the temperature at which the martensite begins to form, and is then cooled slowly in air. In martempering the steel is withdrawn from the quench at the same point, and is then placed in a constant-temperature bath until it attains a uniform temperature throughout its cross section. The steel is then allowed to cool in air through the temperature range of martensite formation, which for most steels is the range from about 288° C to room temperature. In austempering the steel is quenched in a bath of metal or salt maintained at the constant temperature at which the desired structural change occurs and is held in this bath until the change is complete before being subjected to the final cooling.

Other methods of heat treating steel to harden it are used. In case hardening, a finished piece of steel is given an extremely hard surface by heating it with carbon or nitrogen compounds. These compounds react with the steel, either raising the carbon content or forming nitrides in its surface layer. In carburizing, the piece is heated in charcoal or coke, or in carbonaceous gases such as methane or carbon monoxide. Cyaniding consists of hardening in a bath of molten cyanide salt to form both carbides and nitrides. In nitriding, steels of special composition are hardened by heating them in ammonia gas to form alloy nitrides.

 

 

Unit 4

Text A

 

Building Construction

 

Building Construction is a procedures involved in the erection of various types of structures. The major trend in present-day construction continues away from handcrafting at the building site and toward on-site assembly of ever larger, more integrated subassemblies manufactured away from the site.

Another characteristic of contemporary building, related to the latter trend, is the greater amount of dimensional coordination; that is, buildings are designed and components manufactured in multiples of a standard module (10 cm being standard in the U.S.), which drastically reduces the amount of cutting and fitting required on the building site. A third trend is the production or redevelopment of such large structural complexes as shopping centers, entire campuses, and whole towns or sections of cities.

Words and expressions

structure - строение, здание, сооружение

construction - стройка, строительство; конструкция,

сооружение

assembly - монтаж, сборка

site - местоположение; строительный участок,

стройплощадка

dimensional coordination - приведение данных размеров к общей системе

координат

Exercise 1

Ответьте на следующие вопросы:

1. How do we call procedures involved in the erection of various types of structures?

2. What is the difference between handcrafting at the building site and on-site assembly of prefabricated parts?

3. What later trend characteristic of contemporary building do you know?

4. What is the advantage of the building components manufactured in multiples?

5. What innovation in the construction industry drastically reduces the amount of cutting and fitting on the building site?

6. Is it common in present day construction industry production and redevelopment of huge projects? Name some of such huge projects.

7. What is the difference between production and redevelopment in construction industry?

8. How do you understand the procedure of redevelopment of whole towns and sections of cities?

Exercise 2

Заполните пропуски недостающими по смыслу словами, используя текст:

1. The procedure of the erection of various types of structures is called ….

2. The major trend in present-day construction continues away from … at the building site.

3. On-site assembly of larger, more integrated … manufactured away from the site is one of the major trends in construction industry today.

4. Another characteristic of contemporary building is the greater amount of … coordination.

5. Dimensional coordination means that buildings are designed and components manufactured in … of a standard module.

6. … drastically reduces the amount of cutting and fitting required on the building site.

7. Third major trend in contemporary building is the production or redevelopment of … complexes.

Exercise 3

Соответствуют ли данные предложения содержанию текста:

1. Building Construction is a procedure involved in the erection of continuous production lines.

2. The major characteristics in present-day construction is handcrafting at the building site.

3. Larger, more integrated subassemblies manufactured are usually manufactured at construction site.

4. Another characteristic of 19-th century building construction was the greater amount of dimensional coordination.

5. Application of dimensional coordination means that buildings are designed and components manufactured in multiples of a standard module.

6. Dimensional coordination drastically increases the amount of cutting and fitting on the building site.

7. An important present day characteristic in the construction industry is the production or redevelopment of large structural complexes.

8. Large structural complexes include: hospitals, schools, kindergartens and shops.

Exercise 4

Используя текст, составьте высказывания с данными словами и выражениями:

 

building construction – erection – structure - major trend - present-day construction – handcrafting - building site - on-site assembly - integrated subassemblies - dimensional coordination - standard module – cutting – redevelopment - structural complex - section of a city.

 

 

Exercise 5

Кратко передайте содержание каждого абзаца.

 

Exercise 6

Выделите пять основных идей текста.

 

Exercise 7

Составьте предложения, используя данные выражения:

fabricated structure (сборная конструкция); framed structure (каркасная конструкция); hydraulic structure (гидротехническое сооружение); rigid structure (жесткая конструкция); improper assembly (неправильная сборка); building site (стройплощадка); common multiple (общее кратное).

 

Exercise 8

Переведите на русский язык следующие предложения:

1. Building construction is an ancient human activity.

2. Constructed shelters were one means by which human beings were able to adapt themselves to a wide variety of climates and become a global species.

3. The history of building is marked by a number of trends.

4. Early building materials were perishable, such as leaves, branches, and animal hides.

5. The present state of building construction is complex.

6. There is a wide range of building products and systems which are aimed primarily at groups of building types or markets.

7. The design process for buildings is highly organized.

8. The construction process includes the manufacturers of building products and systems and the craftsmen who assemble them on the building site.

9. Building construction today is a significant part of industrial culture.

 

 

Exercise 9

Переведите на английский язык:

1. В современной России строительная индустрия занимает одно из ведущих мест в промышленности.

2. Основной характеристикой современного строительства является ее высокая механизация.

3. Строительные организации занимаются монтажом различных типов конструкций.

4. Объемы ручного труда на строительстве с каждым годом уменьшаются.

5. Крупные и интегрированные детали для строительства изготавливаются на специализированных предприятиях.

6. Размерная координация направлена на ускорение строительства объектов.

7. Подгонка и сварка на строительстве занимают большое количество рабочего времени и человеческих ресурсов.

8. В последние годы появилась тенденция строительства или реконструкции крупных структурных комплексов.

9. Крупным структурным строительным комплексом является строительство жилого комплекса «Солнечный Город».

Exercise 10

Текст на самостоятельный перевод:

Construction

Building construction is an ancient human activity. It began with the purely functional need for a controlled environment to moderate the effects of climate. Constructed shelters were one means by which human beings were able to adapt themselves to a wide variety of climates and become a global species.

Human shelters were at first very simple and perhaps lasted only a few days or months. Over time, however, even temporary structures evolved into such highly refined forms as the igloo. Gradually more durable structures began to appear, particularly after the advent of agriculture, when people began to stay in one place for long periods. The first shelters were dwellings, but later other functions, such as food storage and ceremony, were housed in separate buildings. Some structures began to have symbolic as well as functional value, marking the beginning of the distinction between architecture and building.

The history of building is marked by a number of trends. One is the increasing durability of the materials used. Early building materials were perishable, such as leaves, branches, and animal hides. Later, more durable natural materials—such as clay, stone, and timber—and, finally, synthetic materials—such as brick, concrete, metals, and plastics—were used. Another is a quest for buildings of ever greater height and span; this was made possible by the development of stronger materials and by knowledge of how materials behave and how to exploit them to greater advantage. A third major trend involves the degree of control exercised over the interior environment of buildings: increasingly precise regulation of air temperature, light and sound levels, humidity, odors, air speed, and other factors that affect human comfort has been possible. Yet another trend is the change in energy available to the construction process, starting with human muscle power and developing toward the powerful machinery used today.

The present state of building construction is complex. There is a wide range of building products and systems which are aimed primarily at groups of building types or markets. The design process for buildings is highly organized and draws upon research establishments that study material properties and performance, code officials who adopt and enforce safety standards, and design professionals who determine user needs and design a building to meet those needs. The construction process is also highly organized; it includes the manufacturers of building products and systems, the craftsmen who assemble them on the building site, the contractors who employ and coordinate the work of the craftsmen, and consultants who specialize in such aspects as construction management, quality control, and insurance.

Building construction today is a significant part of industrial culture, a manifestation of its diversity and complexity and a measure of its mastery of natural forces, which can produce a widely varied built environment to serve the diverse needs of society.

Text B

Construction Industry

 

Building construction is the product of a diverse group of subindustries, with many individuals and organizations involved in the construction of a single structure, from the manufacture of necessary components to final assembly. As a general rule, state laws require a registered architect or engineer, or both, to execute the design and to make sure that the design complies with public health, zoning, and building-code requirements. The design must at the same time conform to the requirements of the owner. The architect or engineer converts these requirements into a set of drawings and written specifications that usually are sent to interested general contractors for bids. The successful bidder or bidders in turn subcontract plumbing, painting, electrical wiring, structural frame construction and erection, and other jobs to firms specializing in these crafts.

Contractors ordinarily carry out their work under the observation of an architect and or engineer, who acts as agent of the owner. State and local inspectors review the work for general compliance with the local building code. The immediate responsibility of the contractor, architect, and engineer ends when the local authorities approve the building for occupancy and the owner accepts the building. However, the contractor, architect, and engineer are legally responsible for any deficiencies in the construction or design for a period of several years after acceptance, the time depending on the terms of the contract and local laws.

Words and expressions

 

Building - строительство

construction - стройка, строительство;

конструкция, сооружение

structure - строение, здание, сооружение;

конструкция, структура

terms of the contract - условия контракта

Exercise 1

Ответьте на следующие вопросы:

 

1. Is building construction a product of a diverse group of sub industries, with many individuals and organizations involved?

2. What industries are engaged in the manufacture of necessary components for construction and final assembly of buildings?

3. Do State laws in Russia require a registered architect or engineer to execute the design?

4. Who is responsible for making the design to comply with public health, zoning, and building-code requirements?

5. Are owners’ requirements taken into consideration by city council authorities?

6. Who is responsible to make the design to conform to the requirements of the owner?

7. What are the next steps taken after a set of drawings and written specifications ready?

8. Who usually perform plumbing, painting, electrical wiring, structural frame construction and erection, and other jobs after the design is approved?

9. Under whose observation the contractors ordinarily carry out their work?

10. When does the immediate responsibility of the contractor, architect, and engineer end?

11. Who are legally responsible for any deficiencies in the construction or design for a period of several years after acceptance?

Exercise 2

Заполните пропуски недостающими по смыслу словами, используя текст:

 

1. Building construction is the product of a diverse group of ….

2. In building construction many … and … are involved in the construction of a single structure.

3. The design is usually executed by a registered … and ….

4. The design should … with public health, zoning, and building-code requirements.

5. The … must conform to the requirements of the owner.

6. Drawings and written specifications are converted into a set of … and ….

7. Contractors carry out their work under the observation of an … and ….

8. Construction inspectors review the work for general compliance with the local ….

9. Contractor, architect, and … are legally responsible for any defects in the construction or design.

Exercise 3

Соответствуют ли данные предложения содержанию текста:

 

1. Building construction is the product of a single group of construction industry.

2. Building construction involves final assembly only.

3. As a general rule, state laws permit to execute the design to any company engaged in manufacturing of building materials.

4. Any building construction design should comply with public health, zoning, and building-code requirements.

5. The design must conform to the requirements of the architect.

6. The owner of a building converts requirements of local authorities into a set of drawings and written specifications.

7. The architect and the engineer subcontract construction and erection jobs to firms specializing in these crafts.

8. Contractors carry out their work under the observation of an architect and an engineer.

9. State and local inspectors review the work for general compliance with the local building code.

10. The contractor, architect, and engineer are legally responsible for any financial difficulties of the owner during the construction period.

Exercise 4

Используя текст, составьте высказывания с данными словами и выражениями:

 

Building construction - single structure - manufacture of components - final assembly - general rule - state laws - registered architect - building-code requirements – to conform to - to subcontract - to act as an agent - to review the work - to be legally responsible for – to depend on - terms of the contract.

Exercise 5

Кратко передайте содержание каждого абзаца.

 

Exercise 6

Выделите пять основных идей текста.

 

Exercise 7

Составьте предложения, используя данные выражения:

· Building (строение, здание); additional building (пристройка); administrative building (административное здание); domestic building (жилое здание); engineering building (производственный корпус); flat building (многоквартирный дом); framed building (каркасная постройка).

· structure (конструкция); atomic structure (строение атома); bearing structure (несущая конструкция); dangerous structure (аварийная конструкция); fabricated structure (сборная конструкция); framed structure (каркасная конструкция; фахверк); internal structure (внутренняя структура); rigid structure (жесткая конструкция); rigid-framed structure (жесткая каркасная конструкция); steel structure (металлоконструкция); supporting structure (несущая конструкция); wood structure (деревянная конструкция).

 

Exercise 8

Переведите на английский язык:

1. Строительная индустрия в России является одной из крупнейших отраслей промышленности.

2. В строительную промышленность входят такие отрасли как: производство строительных материалов и изготовление металлоконструкций.

3. Любая строительная компания должна иметь в своем штате дипломированных инженера строителя и архитектора.

4. Строительный проект должен соответствовать требованиям строительных норм и правил.

5. Архитектор и инженер строительного проекта выполняют чертежи и составляют спецификации, по которым строители проводят работы.

6. Генеральный подрядчик проводит тендеры на проведение сантехнических, отделочных, электромонтажных и других работ.

7. Подрядчики выполняют все строительные работы под наблюдением архитектора и главного инженера проекта.

8. Все работы на строительных объектах выполняются в строгом соответствии со строительными нормами и правилами.

9. Генподрядчик архитектор и главный инженер проекта юридически ответственны за все нарушения строительных норм и правил.

 

Exercise 10

Текст на самостоятельный перевод:

Elements of a Building

The major elements of a building include the following: (1) the foundation, which supports the building and provides stability; (2) the structure, which supports all the imposed loads and transmits them to the foundation; (3) the exterior walls, which may or may not be part of the primary supporting structure; (4) the interior partitions, which also may or may not be part of the primary structure; (5) the environmental-control systems, including the heating, ventilating, air-conditioning, lighting, and acoustical systems; (6) the vertical transportation systems, including elevators, escalators, and stairways; (7) communications, which may include such subsystems as intercommunications, public address, and closed-circuit television, as well as the more usual telephone-wiring systems; and (8) the power, water supply, and waste disposal systems.

Building Loads

The loads imposed on a building are classified as either “dead” or “live.” Dead loads include the weight of the building itself and all major items of fixed equipment. Dead loads always act directly downward, act constantly, and are additive from the top of the building down. Live loads include wind pressure, seismic forces, vibrations caused by machinery, movable furniture, stored goods and equipment, occupants, and forces caused by temperature changes. Live loads are temporary and can produce pulsing, vibratory, or impact stresses. In general, the design of a building must accommodate all possible dead and live loads to prevent the building from settling or collapsing and to prevent any permanent distortion, excessive motion, discomfort to occupants, or rupture at any point.

Text C

Foundations

 

The structural design of a building depends greatly on the nature of the soil and underlying geologic conditions and modification by man of either of these factors

Ground Conditions

If a building is to be constructed in an area that has a history of earthquake activity, the earth must be investigated to a considerable depth. Faults in the crust of the earth beneath the soil must obviously be avoided. Some soils may liquefy when subjected to the shock waves of a quake and become like quicksand. In such cases, either construction must be avoided altogether or the foundation must be made deep enough to reach solid material below the potentially unstable soil. Certain clay soils have been found to expand 23 cm or more if subjected to long cycles of drying or wetting, thus producing powerful forces that can shear foundations and lift lightweight buildings. Some soils with high organic content may, over time, compress under the building load to a fraction of their original volume, causing the structure to settle. Other soils tend to slide under loads.

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