ТОП 10:

Steel Melting, Smelters and Continuous Casting Plant



When steels and other metals are melted and refined in arc furnaces and converters, components such as extraction hoods, flue gas ducts, dampers, hatches, bridges, and the preheaters for ladles and scrap are subjected to high thermal stresses. This applies particularly to equipment which cannot be protected by water cooling or refractory lining. Depending on the maximum service temperature, steels of type 153 MA or 253 MA may be used in these applications to avoid serious deformation and frequent repairs.

 

Rolling Mills

Furnaces for heating ingots or billets before rolling or forging are usually box-type or continuous furnaces. Gas or oil burners or electric resistance elements are used for heating. In such furnaces, the components that are subjected to high temperature stresses are principally the rollers, slide-rails or walking beams used for moving the material through the furnace. The framework and edge reinforcements for the charging and discharging doors are also subjected to high temperatures.

Due to its high creep strength, Avesta type 253 MA steel has proved to be an excellent material for such components. Numerous installations at rolling mills in several countries have yielded very favourable results.

Heat Treatment Furnaces

Steelworks, metal works and special hardening shops carry out heat treatment to give various products the required properties. Many different types of furnaces with different atmospheres and temperature cycles are used for this purpose. If heat treatment requires a controlled furnace atmosphere - an inert gas, an active gas or vacuum-gas - tight inner casing is used for the furnace. This is known as a muffle or retort which is made of high-temperature steel or nickel alloy. The retort is actually a pressure vessel and is thus intended for higher gas pressures than a muffle.

 

Вариант № 4

Задание I. Определите в следующих предложениях форму и функцию герундия; переведите предложения на русский язык:

1. Adding heat to a substance does not always cause a rise in its temperature. 2. We can produce heat by burning oil, gas or any other fuel. 3. Have you any objections to introducing a new catalyst? 4. This well-known company began manufacturing synthetic catalysts in 1942. 5. They could not afford carrying out another unsuccessful experiment. 6. Experienced laboratory assistants preferred heating the mixture for two days. 7. We faced the problem of finding a structure for those hydroxides.

 

Задание II. Определите функцию и форму причастия в предложении; предложения переведите:

1. Having been arranged by Mendeleyev in the table, the elements showed their periodic dependence upon the atomic weights. 2. Having separated nitrogen from other gases, researchers obtained it in nearly pure condition. 3. Salt is one of the most common minerals used in everyday life. 4. The element produced by this method behaved like an alkali-metal. 5. The number of scientific papers dealing with electro-oxidation of the element is very limited. 6. Having learned the weight of hydrogen and oxygen, the laboratory assistants determined the ratio of two elements.

Задание III. Определите форму и функцию инфинитива в предложении; предложения переведите:

1. We have come to the blast-furnace shop to observe the work of a continuous casting machine. 2. The scientist’s assistant was the last to come to the laboratory to carry a variety of additional tests. 3. The researchers’ purpose was to obtain a new alloy with the properties of copper and silver. 4. The alloy to be used for this purpose will contain little iron. 5. The machinery to be installed in the blast-furnace shop is provided with automatic devices. 6. Limestone is used in the blast-furnace process to combine with the impurities in the ore.

 

Задание IV. Переведите письменно текст, пользуясь металлургическим словарем.

Bell-type Furnaces

The bell-type furnace consists of a vertical cylindrical or rectangular shell, with a domed end welded to the top. The shell or “bell” has refractory insulation and is placed over the muffle. It thus encloses the material to be heat treated in a controlled furnace atmosphere. Heating is carried out by gas or oil burners, by electric resistance elements or by radiant tubes between the bell and the muffle. A fan on the underside of the muffle circulates the hot gas to ensure a uniform temperature throughout the furnace. The material to be heat treated may be coils of strip, wire rod, bar or small parts. The material is placed on a base above a grid known as the diffuser which helps circulate the gas in the muffle.

The problems usually arising are that the muffle is distorted adjacent to the burner zones due to non-uniform temperature or that the entire bottom part of the muffle deforms due to creep. The base, diffuser and fan impeller may also distort as a result of the high temperatures and mechanical stresses.

The material used for the muffle depends on the maximum service temperature and the atmosphere in the furnace. Avesta 153 MA and 253 MA steels are suitable alternatives to conventional high-temperature steels, such as Avesta 23-13 (309S), 25-20 (310S) or 20-12Si. Avesta 153 MA and 253 MA steels have better creep strength and structure stability (reduced risk of brittleness). Furnace components made of these materials are therefore easier to repair and require less maintenance. Type 253 MA steel should be employed for temperatures above 850°C. If there is risk of carbon or nitrogen pick-up, more highly alloyed nickel alloys such as 353 MA will be more suitable.

Вариант № 5

Задание I. Определите в следующих предложениях форму и функцию герундия; переведите предложения на русский язык:

1. There are several ways of handling this difficulty. 2. This is a new device for measuring blood pressure. 3. A discussion on solving the problem of metal shortage was under way. 4. When a liquid starts boiling at a certain temperature and under a given pressure, the heat causes the liquid to vaporize. 5. The rate of evaporation also depends on evaporating surface. 6. After purifying the water laboratory assistants could use it for drinking.7. Because of the reaction with water sodium must be protected from the moisture of the air by being kept under kerosene.

 

Задание II. Определите функцию и форму причастия в предложении; предложения переведите:

1. Hydrogen reacts with oxides of a number of metals forming water and free metal. 2. Water used in steam boilers, should be free from substances which cause corrosion. 3. Using isotopes it is possible to make the control of pig-iron and steel production process cheaper. 4. The device designed by the group of engineers meets all the customers’ requirements. 5. The metric system used in CIS differed from a non-metric system used in the USA. 6. The achieved speed was 130 km. p. h.

 

Задание III. Определите форму и функцию инфинитива в предложении; предложения переведите:

1. To involve computational problems is difficult without some practice in solving ordinary differential equations. 2. The data to be analysed involve knowledge of numerical methods. 3. To understand many complicated phenomena in terms of few simple principles physicists develop theories. 4. The solid to be used is highly soluble in water. 5. The object of the experiment is to test the results obtained. 6. The research group didn’t know the exact temperature of the alloy produced, so it must be going on with the measurements.

 

Задание IV. Переведите письменно текст, пользуясь металлургическим словарем:

Вариант № 6

 

Задание I. Определите в следующих предложениях форму и функцию герундия; переведите предложения на русский язык:

1. The host cell stops dividing. 2. They have put off discussing the problem of environmental protection. 3. I like studying physics and chemistry. 4. Without finding out the nature of the new compound the scientist cannot continue his experiments. 5. In melting the ice keeps the same temperature. 6. The rule against visitors entering the laboratory at the time of the experiment is strict. 7. This apparatus is used for recording the temperature.

 

Задание II. Определите функцию и форму причастия в предложении; предложения переведите:

1. Using isotopes in measuring the diffusion of metals we got much more accurate data. 2. Being used in measuring the diffusion of metals, isotopes gave much more accurate data. 3. Scientists have found a simple way to produce a laser beam of any colour and frequency desired. 4. Heating metals, we increase their conductivity. 5. Having studied the properties of this alloy, the scientist arrived at the conclusion that it might be used in industry. 6. Being heated, metals become more conductive.

 

Задание III. Определите форму и функцию инфинитива в предложении; предложения переведите:

1. The object of the experiment is to test the results obtained and research workers are to provide the necessary equipment. 2. One of the most common methods of dissolving precipitates is their chemical conversion into soluble products. 3. In writing formulas, the symbol for the positive element is written first, as in NaCl. 4. We know all bodies to consist of atoms. 5. After being recrystallized from ethyl alcohol the solid began melting. 6. Physics is the science to be concerned with in all other natural sciences.

 

Задание IV. Переведите письменно текст, пользуясь металлургическим словарем:







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