Misplaced Pages

#848151

87-578: The Union Colliery Company was a bituminous coal mining company based in St. Louis Missouri. The company had branch offices in Milwaukee, Racine, and Kenosha, Wisconsin, as well as Detroit, Michigan. The company was acquired in 1937 by East St. Louis Light and Power. This company eventually became Union Electric Company . It remained a subsidiary until ceasing operations in June, 1958. The company operated

174-412: A BOS process is manufactured in one-twelfth the time. Today, electric arc furnaces (EAF) are a common method of reprocessing scrap metal to create new steel. They can also be used for converting pig iron to steel, but they use a lot of electrical energy (about 440 kWh per metric ton), and are thus generally only economical when there is a plentiful supply of cheap electricity. The steel industry

261-531: A brittle alloy commonly called pig iron . Alloy steel is steel to which other alloying elements have been intentionally added to modify the characteristics of steel. Common alloying elements include: manganese , nickel , chromium , molybdenum , boron , titanium , vanadium , tungsten , cobalt , and niobium . Additional elements, most frequently considered undesirable, are also important in steel: phosphorus , sulphur , silicon , and traces of oxygen , nitrogen , and copper . Plain carbon-iron alloys with

348-713: A carbon-intermediate steel by the 1st century AD. There is evidence that carbon steel was made in Western Tanzania by the ancestors of the Haya people as early as 2,000 years ago by a complex process of "pre-heating" allowing temperatures inside a furnace to reach 1300 to 1400 °C. Evidence of the earliest production of high carbon steel in South Asia is found in Kodumanal in Tamil Nadu ,

435-444: A change of volume. In this case, expansion occurs. Internal stresses from this expansion generally take the form of compression on the crystals of martensite and tension on the remaining ferrite, with a fair amount of shear on both constituents. If quenching is done improperly, the internal stresses can cause a part to shatter as it cools. At the very least, they cause internal work hardening and other microscopic imperfections. It

522-486: A clean coal technology. Steel Steel is an alloy of iron and carbon with improved strength and fracture resistance compared to other forms of iron. Because of its high tensile strength and low cost, steel is one of the most commonly manufactured materials in the world. Steel is used in buildings, as concrete reinforcing rods, in bridges, infrastructure, tools, ships, trains, cars, bicycles, machines, electrical appliances, furniture, and weapons. Iron

609-663: A composition of about 84.4% carbon, 5.4% hydrogen, 6.7% oxygen, 1.7% nitrogen, and 1.8% sulfur, on a weight basis. This implies that chemical processes during coalification remove most of the oxygen and much of the hydrogen, leaving carbon, a process called carbonization . During coalification, the maturing coal increases in carbon content, decreases in hydrogen and volatiles, increases in its heating value, and becomes darker and more lustrous. Chemical changes include dehydration (which removes oxygen and hydrogen as water), decarboxylation (which removes oxygen as carbon dioxide ), and demethanation (which removes hydrogen as methane ). By

696-407: A dry, mineral-matter-free basis, the fixed carbon content is the fraction of the coal that is not volatile organic matter. An agglomerating coal is a coal that softens when heated, forming a hard, gray, porous coke that resists crushing. Vitrinite reflectance is a measure of how reflective a polished surface of an average particle of vitrinite in the coal is. It is determined by how much of

783-428: A ferrite BCC crystal form, but at higher carbon content it takes a body-centred tetragonal (BCT) structure. There is no thermal activation energy for the transformation from austenite to martensite. There is no compositional change so the atoms generally retain their same neighbours. Martensite has a lower density (it expands during the cooling) than does austenite, so that the transformation between them results in

870-583: A hard oxide forms on the metal surface; this is known as stainless steel . Tungsten slows the formation of cementite , keeping carbon in the iron matrix and allowing martensite to preferentially form at slower quench rates, resulting in high-speed steel . The addition of lead and sulphur decrease grain size, thereby making the steel easier to turn , but also more brittle and prone to corrosion. Such alloys are nevertheless frequently used for components such as nuts, bolts, and washers in applications where toughness and corrosion resistance are not paramount. For

957-445: A hard but brittle martensitic structure. The steel is then tempered, which is just a specialized type of annealing, to reduce brittleness. In this application the annealing (tempering) process transforms some of the martensite into cementite, or spheroidite and hence it reduces the internal stresses and defects. The result is a more ductile and fracture-resistant steel. When iron is smelted from its ore, it contains more carbon than

SECTION 10

#1732775794849

1044-434: A higher than 2.1% carbon content are known as cast iron . With modern steelmaking techniques such as powder metal forming, it is possible to make very high-carbon (and other alloy material) steels, but such are not common. Cast iron is not malleable even when hot, but it can be formed by casting as it has a lower melting point than steel and good castability properties. Certain compositions of cast iron, while retaining

1131-412: A narrow range of concentrations of mixtures of carbon and iron that make steel, several different metallurgical structures, with very different properties can form. Understanding such properties is essential to making quality steel. At room temperature , the most stable form of pure iron is the body-centred cubic (BCC) structure called alpha iron or α-iron. It is a fairly soft metal that can dissolve only

1218-413: A relatively dirty fuel. The reduction in the use of bituminous coal between 1945 and 1960 is estimated to have saved at least 1,923 lives of all ages and 310 infant lives per winter month. Bituminous coal quality is improved with floatation methods, which increase the fraction of vitrinite to yield a cleaner-burning product. The bioconversion of bituminous coal to methane is being actively researched as

1305-534: A small concentration of carbon, no more than 0.005% at 0 °C (32 °F) and 0.021 wt% at 723 °C (1,333 °F). The inclusion of carbon in alpha iron is called ferrite . At 910 °C, pure iron transforms into a face-centred cubic (FCC) structure, called gamma iron or γ-iron. The inclusion of carbon in gamma iron is called austenite. The more open FCC structure of austenite can dissolve considerably more carbon, as much as 2.1%, (38 times that of ferrite) carbon at 1,148 °C (2,098 °F), which reflects

1392-434: A softened, sticky mass when heated, which reflects the presence of bitumen (mineral tar) in the coal. Though almost all agglomerating coal is of bituminous rank, some bituminous coal is not agglomerating. Non-agglomerating bituminous coal includes cannel coal and boghead coal . These are nonbanded and nonreflective, and break with a conchoidal fracture. Both are sapropelic , in contrast with most bituminous coal, which

1479-453: A steel's final rolling, it is heat treated for strength; however, this is relatively rare. Steel was known in antiquity and was produced in bloomeries and crucibles . The earliest known production of steel is seen in pieces of ironware excavated from an archaeological site in Anatolia ( Kaman-Kalehöyük ) which are nearly 4,000 years old, dating from 1800 BC. Wootz steel

1566-477: A subsequent step. Other materials are often added to the iron/carbon mixture to produce steel with the desired properties. Nickel and manganese in steel add to its tensile strength and make the austenite form of the iron-carbon solution more stable, chromium increases hardness and melting temperature, and vanadium also increases hardness while making it less prone to metal fatigue . To inhibit corrosion, at least 11% chromium can be added to steel so that

1653-480: A typical composition is about 84.4% carbon, 5.4% hydrogen, 6.7% oxygen, 1.7% nitrogen, and 1.8% sulfur, on a weight basis. Its bank density (the density of a coal seam prior to breaking up during mining) is about 1346 kg/m (84 lb/ft ) while the bulk density of extracted coal is up to 833 kg/m (52 lb/ft ). Bituminous coal characteristically burns with a smoky flame and softens and swells during combustion. It gets its name from this tendency to form

1740-672: Is continuously cast into long slabs, cut and shaped into bars and extrusions and heat treated to produce a final product. Today, approximately 96% of steel is continuously cast, while only 4% is produced as ingots. The ingots are then heated in a soaking pit and hot rolled into slabs, billets , or blooms . Slabs are hot or cold rolled into sheet metal or plates. Billets are hot or cold rolled into bars, rods, and wire. Blooms are hot or cold rolled into structural steel , such as I-beams and rails . In modern steel mills these processes often occur in one assembly line , with ore coming in and finished steel products coming out. Sometimes after

1827-508: Is humic (composed of decayed woody tissue of plants). Cannel coal is composed mostly of plant spores, while boghead coal is composed mostly of nonspore algal remains. In the United States, bituminous coal is further divided into subranks based on its heating value and fixed carbon content. Thus bituminous coal is divided into high-, medium-, and low-volatile categories based on fixed carbon content, and high-volatile bituminous coal

SECTION 20

#1732775794849

1914-449: Is accompanied by peak methane generation. This makes these bituminous coals "gassy" and precautions must be taken against methane explosions. Imidazolium -based ionic liquid solvents can reduce spontaneous combustion, which accounts for 2 to 3 percent of global annual carbon dioxide emissions. Bituminous coal was once extensively used for home heating in the US. However, bituminous coal is

2001-636: Is also very reusable: it is one of the world's most-recycled materials, with a recycling rate of over 60% globally . The noun steel originates from the Proto-Germanic adjective * * stahliją or * * stakhlijan 'made of steel', which is related to * * stahlaz or * * stahliją 'standing firm'. The carbon content of steel is between 0.02% and 2.14% by weight for plain carbon steel ( iron - carbon alloys ). Too little carbon content leaves (pure) iron quite soft, ductile, and weak. Carbon contents higher than those of steel make

2088-416: Is always the main element in steel, but many other elements may be present or added. Stainless steels , which are resistant to corrosion and oxidation , typically need an additional 11% chromium . Iron is the base metal of steel. Depending on the temperature, it can take two crystalline forms (allotropic forms): body-centred cubic and face-centred cubic . The interaction of the allotropes of iron with

2175-401: Is bituminous coal of the highest quality, as free of ash and sulfur as possible, used to manufacture coke for use by blacksmiths . Coking coal commands a higher price than coal used for energy production. As of 2020 , coking coal in the U.S. sold for about $ 127/ short ton , compared with $ 50.05/short ton for bituminous coal generally. The cost of coking coal is about 3.5 times as high as

2262-459: Is classified as sub-bituminous coal. In the international market, bituminous coal is defined as coal with a vitrinite reflectance between 0.5 and 1.9. Vitrinite reflectance is also routinely measured for U.S. coal as a check on its rank classification Bituminous coal is dark brown to black, hard, but friable . It is commonly composed of thin bands of alternating bright and dull material. Though bituminous coal varies in its chemical composition,

2349-403: Is common for quench cracks to form when steel is water quenched, although they may not always be visible. There are many types of heat treating processes available to steel. The most common are annealing , quenching , and tempering . Annealing is the process of heating the steel to a sufficiently high temperature to relieve local internal stresses. It does not create a general softening of

2436-403: Is desirable. To become steel, it must be reprocessed to reduce the carbon to the correct amount, at which point other elements can be added. In the past, steel facilities would cast the raw steel product into ingots which would be stored until use in further refinement processes that resulted in the finished product. In modern facilities, the initial product is close to the final composition and

2523-405: Is extracted from iron ore by removing the oxygen through its combination with a preferred chemical partner such as carbon which is then lost to the atmosphere as carbon dioxide. This process, known as smelting , was first applied to metals with lower melting points, such as tin , which melts at about 250 °C (482 °F), and copper , which melts at about 1,100 °C (2,010 °F), and

2610-523: Is found in the Appalachian and Interior Provinces of North America. Mining is done via both surface and underground mines. Historically, the many seams scattered over rugged terrain in the Appalachians have been conducive to mining by small companies, while the great extent and gentle dip of beds further west favors very large-scale operations. The Appalachian coal is notably low in sulfur and

2697-422: Is further subdivided by energy content. ISO classification of bituminous coal is based on vitrinite reflectance. This classification divides medium rank coal (approximately equivalent to bituminous coal) into four subranks. In order of increasing rank, these are: Bituminous coal is used primarily for electrical power generation and in the manufacture of steel . Coking coal ( metallurgical coal or "met coal")

Union Colliery Company - Misplaced Pages Continue

2784-408: Is heat treated to contain both a ferritic and martensitic microstructure to produce a formable, high strength steel. Transformation Induced Plasticity (TRIP) steel involves special alloying and heat treatments to stabilize amounts of austenite at room temperature in normally austenite-free low-alloy ferritic steels. By applying strain, the austenite undergoes a phase transition to martensite without

2871-691: Is often considered an indicator of economic progress, because of the critical role played by steel in infrastructural and overall economic development . In 1980, there were more than 500,000 U.S. steelworkers. By 2000, the number of steelworkers had fallen to 224,000. The economic boom in China and India caused a massive increase in the demand for steel. Between 2000 and 2005, world steel demand increased by 6%. Since 2000, several Indian and Chinese steel firms have expanded to meet demand, such as Tata Steel (which bought Corus Group in 2007), Baosteel Group and Shagang Group . As of 2017 , though, ArcelorMittal

2958-692: Is often of metallurgical grade, while the Interior Province coal is much higher in sulfur. The belt of Carboniferous coal fields extends into central Europe, and much of this is bituminous coal. Bituminous coal fields are found in Poland and the Czech Republic, and the Polish deposits are one of the most important of that nation's natural resources. The Czech deposits have been exploited since prehistoric times. The European deposits include

3045-488: Is one of the world's most-recycled materials, with a recycling rate of over 60% globally; in the United States alone, over 82,000,000 metric tons (81,000,000 long tons; 90,000,000 short tons) were recycled in the year 2008, for an overall recycling rate of 83%. As more steel is produced than is scrapped, the amount of recycled raw materials is about 40% of the total of steel produced - in 2016, 1,628,000,000 tonnes (1.602 × 10 long tons; 1.795 × 10 short tons) of crude steel

3132-487: Is submerged in standing water. The stagnant water excludes oxygen, creates an acidic environment, and slows decay. The dead plant material is converted to peat . Peat is mostly a mixture of cellulose , hemicellulose , and lignin that originally made up the woody tissue of the plants. Lignin has a weight composition of about 54% carbon, 6% hydrogen, and 30% oxygen, while cellulose has a weight composition of about 44% carbon, 6% hydrogen, and 49% oxygen. Bituminous coal has

3219-547: Is the world's largest steel producer . In 2005, the British Geological Survey stated China was the top steel producer with about one-third of the world share; Japan , Russia , and the United States were second, third, and fourth, respectively, according to the survey. The large production capacity of steel results also in a significant amount of carbon dioxide emissions inherent related to

3306-438: Is used for the production of activated carbon . The coal is first coked, removing volatiles, then steam treated to activate it. Chemical processes for activating coke produced from bituminous coal have also been investigated. Like other ranks of coal, bituminous coal forms from thick accumulations of dead plant material that are buried faster than they can decay. This usually takes place in peat bogs , where falling plant debris

3393-481: Is used in the manufacture of steel . A good coking coal must have excellent agglomeration properties, a high carbon content, and a low content of sulfur, phosphorus , and ash. The best unblended coking coal is high quality medium-volatile bituminous coal. However, since single coals with all the necessary properties are scarce, coking coal is usually a blend of high-volatile bituminous coal with lesser amounts of medium- and low-volatile bituminous coal. Smithing coal

3480-582: The Coal Measures of Britain, which account for most of Britain's coal production and which are mostly bituminous coal. The Westfield coal basin is the largest in Britain. Other significant bituminous coal deposits are found through much of Europe, including France, Germany, and northern Italy. Coal deposition was interrupted by the Permian-Triassic extinction event , but resumed later in

3567-648: The Gates Formation . The Intermontane and Insular Coalfields of British Columbia also contain deposits of Cretaceous bituminous coal. As of 2009 , the countries with the greatest estimated ultimately recoverable resources of bituminous coal were the US, 161.6 Gt ; India, 99.7 Gt; China, 78.4 Gt; Australia, 51.3 Gt; South Africa, 38.7 Gt; the UK, 26.8 Gt; Germany, 25.2 Gt; Colombia, 7.8 Gt; Indonesia, 5.6 Gt; and France, 4.4 Gt As of 2018 , total world production of bituminous coal (coking coal plus other bituminous coal)

Union Colliery Company - Misplaced Pages Continue

3654-655: The Golconda area in Andhra Pradesh and Karnataka , regions of India , as well as in Samanalawewa and Dehigaha Alakanda, regions of Sri Lanka . This came to be known as wootz steel , produced in South India by about the sixth century BC and exported globally. The steel technology existed prior to 326 BC in the region as they are mentioned in literature of Sangam Tamil , Arabic, and Latin as

3741-772: The Middle Triassic . Extensive bituminous coal deposits of Permian age are found in Siberia, east Asia, and Australia. These include the Minusinsky coal basin in Siberia, the Queensland , Bowen , and Sydney Basins in Australia, and the extensive bituminous coal reserves of China. A second peak in coal deposition began in the Cretaceous , though most of this is lower rank coal rather than bituminous. In

3828-599: The cementation process was described in a treatise published in Prague in 1574 and was in use in Nuremberg from 1601. A similar process for case hardening armour and files was described in a book published in Naples in 1589. The process was introduced to England in about 1614 and used to produce such steel by Sir Basil Brooke at Coalbrookdale during the 1610s. The raw material for this process were bars of iron. During

3915-436: The coal mining industry, this type of coal is known for releasing the largest amounts of firedamp , a dangerous mixture of gases that can cause underground explosions. Extraction of bituminous coal demands the highest safety procedures involving attentive gas monitoring, good ventilation and vigilant site management. Bituminous coal is a particular rank of coal , as determined by the amount and type of carbon present in

4002-419: The hardness , quenching behaviour , need for annealing , tempering behaviour , yield strength , and tensile strength of the resulting steel. The increase in steel's strength compared to pure iron is possible only by reducing iron's ductility. Steel was produced in bloomery furnaces for thousands of years, but its large-scale, industrial use began only after more efficient production methods were devised in

4089-445: The 17th century, it was realized that the best steel came from oregrounds iron of a region north of Stockholm , Sweden. This was still the usual raw material source in the 19th century, almost as long as the process was used. Crucible steel is steel that has been melted in a crucible rather than having been forged , with the result that it is more homogeneous. Most previous furnaces could not reach high enough temperatures to melt

4176-475: The 17th century, the first step in European steel production has been the smelting of iron ore into pig iron in a blast furnace . Originally employing charcoal, modern methods use coke , which has proven more economical. In these processes, pig iron made from raw iron ore was refined (fined) in a finery forge to produce bar iron , which was then used in steel-making. The production of steel by

4263-626: The 17th century, with the introduction of the blast furnace and production of crucible steel . This was followed by the Bessemer process in England in the mid-19th century, and then by the open-hearth furnace . With the invention of the Bessemer process, a new era of mass-produced steel began. Mild steel replaced wrought iron . The German states were the major steel producers in Europe in

4350-481: The 19th century. American steel production was centred in Pittsburgh , Bethlehem, Pennsylvania , and Cleveland until the late 20th century. Currently, world steel production is centered in China, which produced 54% of the world's steel in 2023. Further refinements in the process, such as basic oxygen steelmaking (BOS), largely replaced earlier methods by further lowering the cost of production and increasing

4437-608: The Arabs from Persia, who took it from India. It was originally created from several different materials including various trace elements , apparently ultimately from the writings of Zosimos of Panopolis . In 327 BC, Alexander the Great was rewarded by the defeated King Porus , not with gold or silver but with 30 pounds of steel. A recent study has speculated that carbon nanotubes were included in its structure, which might explain some of its legendary qualities, though, given

SECTION 50

#1732775794849

4524-473: The Earth's geologic history. Vast deposits of coal formed in wetlands —called coal forests —that covered much of the Earth's tropical land areas during the late Carboniferous ( Pennsylvanian ) and Permian times. Bituminous coal is predominantly Carboniferous in age. Most bituminous coal in the United States is between 100 and 300 million years old. Vast deposits of bituminous coal of Pennsylvanian age

4611-470: The Linz-Donawitz process of basic oxygen steelmaking (BOS), developed in 1952, and other oxygen steel making methods. Basic oxygen steelmaking is superior to previous steelmaking methods because the oxygen pumped into the furnace limited impurities, primarily nitrogen, that previously had entered from the air used, and because, with respect to the open hearth process, the same quantity of steel from

4698-714: The United States, Cretaceous bituminous coals occur in Wyoming, Colorado and New Mexico. In Canada, the Western Canada Sedimentary Basin of Alberta and British Columbia hosts major deposits of bituminous coal that formed in swamps along the western margin of the Western Interior Seaway . They range in age from latest Jurassic or earliest Cretaceous in the Mist Mountain Formation , to Late Cretaceous in

4785-401: The alloying elements, primarily carbon, gives steel and cast iron their range of unique properties. In pure iron, the crystal structure has relatively little resistance to the iron atoms slipping past one another, and so pure iron is quite ductile , or soft and easily formed. In steel, small amounts of carbon, other elements, and inclusions within the iron act as hardening agents that prevent

4872-436: The austenite grain boundaries until the percentage of carbon in the grains has decreased to the eutectoid composition (0.8% carbon), at which point the pearlite structure forms. For steels that have less than 0.8% carbon (hypoeutectoid), ferrite will first form within the grains until the remaining composition rises to 0.8% of carbon, at which point the pearlite structure will form. No large inclusions of cementite will form at

4959-471: The austenite is for it to precipitate out of solution as cementite , leaving behind a surrounding phase of BCC iron called ferrite with a small percentage of carbon in solution. The two, cementite and ferrite, precipitate simultaneously producing a layered structure called pearlite , named for its resemblance to mother of pearl . In a hypereutectoid composition (greater than 0.8% carbon), the carbon will first precipitate out as large inclusions of cementite at

5046-494: The boundaries in hypoeutectoid steel. The above assumes that the cooling process is very slow, allowing enough time for the carbon to migrate. As the rate of cooling is increased the carbon will have less time to migrate to form carbide at the grain boundaries but will have increasingly large amounts of pearlite of a finer and finer structure within the grains; hence the carbide is more widely dispersed and acts to prevent slip of defects within those grains, resulting in hardening of

5133-573: The carbon has condensed to an aromatic form from the heat and pressure of deep burial. In the United States, bituminous coal is defined as agglomerating coal yielding at least 10,500 Btu /lb (24,400 kJ/kg) of energy on combustion (on a moist, mineral-matter-free basis), with a fixed carbon content less than 86% (on a dry, mineral-matter-free basis.) Coal with a higher fixed carbon content is classified as anthracite, while agglomerating coal yielding less than 10,500 Btu/lb (24,400 kJ/kg) or nonagglomerating coal yielding less than 11,500 Btu/lb (26,700 kJ/kg)

5220-400: The coal and the amount of energy it can produce when burned. It is higher in rank than sub-bituminous coal but lower in rank than anthracite . Bituminous coal is the most abundant rank of coal. Coal rank is based on several characteristics of the coal. The fixed carbon content refers to the percentage of the coal that is neither moisture, nor ash, nor volatile matter. When evaluated on

5307-561: The coal reaches temperatures above about 235 °C (455 °F), bitumen breaks down ( debituminization ) and the coal matures to anthracite. Coal deposits are widely distributed worldwide, and range in age from the Devonian (about 360 to 420 million years ago) to Neogene deposits just a few million years old. However, 90% of all coal beds were deposited in the Carboniferous and Permian periods , which represent just 2% of

SECTION 60

#1732775794849

5394-455: The combination, bronze, which has a melting point lower than 1,083 °C (1,981 °F). In comparison, cast iron melts at about 1,375 °C (2,507 °F). Small quantities of iron were smelted in ancient times, in the solid-state, by heating the ore in a charcoal fire and then welding the clumps together with a hammer and in the process squeezing out the impurities. With care, the carbon content could be controlled by moving it around in

5481-416: The cost of coal used for electrical power (which includes lower ranks of coal, such sub-bituminous coal and lignite , as well as noncoking bituminous coal.) Bituminous coal which lacks the qualities required for use as metallurgical coal is graded as thermal coal. This is used primarily for electrical power generation. The ideal thermal coal is easily ignited but has a high heat content. Bituminous coal

5568-400: The economies of melting and casting, can be heat treated after casting to make malleable iron or ductile iron objects. Steel is distinguishable from wrought iron (now largely obsolete), which may contain a small amount of carbon but large amounts of slag . Iron is commonly found in the Earth's crust in the form of an ore , usually an iron oxide, such as magnetite or hematite . Iron

5655-648: The finest steel in the world exported to the Roman, Egyptian, Chinese and Arab worlds at that time – what they called Seric Iron . A 200 BC Tamil trade guild in Tissamaharama , in the South East of Sri Lanka, brought with them some of the oldest iron and steel artifacts and production processes to the island from the classical period . The Chinese and locals in Anuradhapura , Sri Lanka had also adopted

5742-579: The fire. Unlike copper and tin, liquid or solid iron dissolves carbon quite readily. All of these temperatures could be reached with ancient methods used since the Bronze Age . Since the oxidation rate of iron increases rapidly beyond 800 °C (1,470 °F), it is important that smelting take place in a low-oxygen environment. Smelting, using carbon to reduce iron oxides, results in an alloy ( pig iron ) that retains too much carbon to be called steel. The excess carbon and other impurities are removed in

5829-400: The following mines: Bituminous coal Bituminous coal is used primarily for electrical power generation and in the steel industry . Bituminous coal suitable for smelting iron ( coking coal or metallurgical coal ) must be low in sulfur and phosphorus . It commands a higher price than other grades of bituminous coal (thermal coal) used for heating and power generation. Within

5916-513: The form of charcoal) in a crucible, was produced in Merv by the 9th to 10th century AD. In the 11th century, there is evidence of the production of steel in Song China using two techniques: a "berganesque" method that produced inferior, inhomogeneous steel, and a precursor to the modern Bessemer process that used partial decarburization via repeated forging under a cold blast . Since

6003-599: The hardenability of thick sections. High strength low alloy steel has small additions (usually < 2% by weight) of other elements, typically 1.5% manganese, to provide additional strength for a modest price increase. Recent corporate average fuel economy (CAFE) regulations have given rise to a new variety of steel known as Advanced High Strength Steel (AHSS). This material is both strong and ductile so that vehicle structures can maintain their current safety levels while using less material. There are several commercially available grades of AHSS, such as dual-phase steel , which

6090-439: The main production route. At the end of 2008, the steel industry faced a sharp downturn that led to many cut-backs. In 2021, it was estimated that around 7% of the global greenhouse gas emissions resulted from the steel industry. Reduction of these emissions are expected to come from a shift in the main production route using cokes, more recycling of steel and the application of carbon capture and storage technology. Steel

6177-450: The most part, however, p-block elements such as sulphur, nitrogen , phosphorus , and lead are considered contaminants that make steel more brittle and are therefore removed from steel during the melting processing. The density of steel varies based on the alloying constituents but usually ranges between 7,750 and 8,050 kg/m (484 and 503 lb/cu ft), or 7.75 and 8.05 g/cm (4.48 and 4.65 oz/cu in). Even in

6264-446: The movement of dislocations . The carbon in typical steel alloys may contribute up to 2.14% of its weight. Varying the amount of carbon and many other alloying elements, as well as controlling their chemical and physical makeup in the final steel (either as solute elements, or as precipitated phases), impedes the movement of the dislocations that make pure iron ductile, and thus controls and enhances its qualities. These qualities include

6351-552: The nature of the original plant material, nor the length of burial is nearly as important. The temperature range for maturation of bituminous coal is from 85 to 235 °C (185 to 455 °F). The bitumen that characterizes bituminous coal forms under approximately the same conditions at which petroleum is formed in petroleum source rocks. Bituminization is accompanied by peak methane generation in medium to low volatile bituminous coal. This makes these bituminous coals "gassy" and precautions must be taken against methane explosions. If

6438-449: The product but only locally relieves strains and stresses locked up within the material. Annealing goes through three phases: recovery , recrystallization , and grain growth . The temperature required to anneal a particular steel depends on the type of annealing to be achieved and the alloying constituents. Quenching involves heating the steel to create the austenite phase then quenching it in water or oil . This rapid cooling results in

6525-759: The production methods of creating wootz steel from the Chera Dynasty Tamils of South India by the 5th century AD. In Sri Lanka, this early steel-making method employed a unique wind furnace, driven by the monsoon winds, capable of producing high-carbon steel. Since the technology was acquired from the Tamilians from South India, the origin of steel technology in India can be conservatively estimated at 400–500 BC. The manufacture of wootz steel and Damascus steel , famous for its durability and ability to hold an edge, may have been taken by

6612-426: The quality of the final product. Today more than 1.6 billion tons of steel is produced annually. Modern steel is generally identified by various grades defined by assorted standards organizations . The modern steel industry is one of the largest manufacturing industries in the world, but also one of the most energy and greenhouse gas emission intense industries, contributing 8% of global emissions. However, steel

6699-401: The steel. At the very high cooling rates produced by quenching, the carbon has no time to migrate but is locked within the face-centred austenite and forms martensite . Martensite is a highly strained and stressed, supersaturated form of carbon and iron and is exceedingly hard but brittle. Depending on the carbon content, the martensitic phase takes different forms. Below 0.2% carbon, it takes on

6786-561: The steel. The early modern crucible steel industry resulted from the invention of Benjamin Huntsman in the 1740s. Blister steel (made as above) was melted in a crucible or in a furnace, and cast (usually) into ingots. The modern era in steelmaking began with the introduction of Henry Bessemer 's process in 1855, the raw material for which was pig iron. His method let him produce steel in large quantities cheaply, thus mild steel came to be used for most purposes for which wrought iron

6873-399: The structural element of graphite . This is accompanied by an increase in vitrinite reflectance, used to assess coal rank. During coalification, the pressure of burial reduces the volume of the original peat by a factor of 30 as it is converted to coal. However, the increase in rank of maturing coal mostly reflects the maximum temperature the coal reaches. Neither the maximum pressure, nor

6960-561: The technology of that time, such qualities were produced by chance rather than by design. Natural wind was used where the soil containing iron was heated by the use of wood. The ancient Sinhalese managed to extract a ton of steel for every 2 tons of soil, a remarkable feat at the time. One such furnace was found in Samanalawewa and archaeologists were able to produce steel as the ancients did. Crucible steel , formed by slowly heating and cooling pure iron and carbon (typically in

7047-659: The time the coal reaches bituminous rank, most dehydration and decarboxylation has already taken place, and maturation of bituminous coal is characterized by demethanation. During coalification at bituminous rank, coal approaches its maximum heating value and begins to lose most of its volatile content. As carbonization proceeds, aliphatic compounds (carbon compounds characterized by chains of carbon atoms) are replaced by aromatic compounds (carbon compounds characterized by rings of carbon atoms) and aromatic rings begin to fuse into polyaromatic compounds (linked rings of carbon atoms). The structure increasingly resembles graphene ,

7134-525: The upper carbon content of steel, beyond which is cast iron. When carbon moves out of solution with iron, it forms a very hard, but brittle material called cementite (Fe 3 C). When steels with exactly 0.8% carbon (known as a eutectoid steel), are cooled, the austenitic phase (FCC) of the mixture attempts to revert to the ferrite phase (BCC). The carbon no longer fits within the FCC austenite structure, resulting in an excess of carbon. One way for carbon to leave

7221-444: Was 6.220 Gt. The leading producer is China, with India and the United States a distant second and third. U.S. production of bituminous coal was 238 million short tons in 2020 and represented 44% of all U.S. coal production. Bituminous coal is mined in 18 states, but the five states of West Virginia, Pennsylvania, Illinois, Kentucky, and Indiana produce 74%of U.S. coal. Maturation of bituminous coal at medium and low volatile subrank

7308-718: Was developed in Southern India and Sri Lanka in the 1st millennium BCE. Metal production sites in Sri Lanka employed wind furnaces driven by the monsoon winds, capable of producing high-carbon steel. Large-scale wootz steel production in India using crucibles occurred by the sixth century BC, the pioneering precursor to modern steel production and metallurgy. High-carbon steel was produced in Britain at Broxmouth Hillfort from 490–375 BC, and ultrahigh-carbon steel

7395-509: Was formerly used. The Gilchrist-Thomas process (or basic Bessemer process ) was an improvement to the Bessemer process, made by lining the converter with a basic material to remove phosphorus. Another 19th-century steelmaking process was the Siemens-Martin process , which complemented the Bessemer process. It consisted of co-melting bar iron (or steel scrap) with pig iron. These methods of steel production were rendered obsolete by

7482-438: Was produced globally, with 630,000,000 tonnes (620,000,000 long tons; 690,000,000 short tons) recycled. Modern steels are made with varying combinations of alloy metals to fulfil many purposes. Carbon steel , composed simply of iron and carbon, accounts for 90% of steel production. Low alloy steel is alloyed with other elements, usually molybdenum , manganese, chromium, or nickel, in amounts of up to 10% by weight to improve

7569-757: Was produced in the Netherlands from the 2nd-4th centuries AD. The Roman author Horace identifies steel weapons such as the falcata in the Iberian Peninsula , while Noric steel was used by the Roman military . The Chinese of the Warring States period (403–221 BC) had quench-hardened steel, while Chinese of the Han dynasty (202 BC—AD 220) created steel by melting together wrought iron with cast iron, thus producing

#848151