82-459: The Springvale Botanical Cemetery is the largest crematorium and memorial park in Victoria, Australia , located in the southeastern Melbourne suburb of Springvale . Originally known as The Necropolis Springvale, the cemetery commenced operations in 1901. Between 1904 and 1952 it was served by its own railway branch line and station , by which coffins, passengers and staff were conveyed to
164-568: A chapel . Some crematoria also incorporate a columbarium , a place for interring cremation ashes. Prior to the Industrial Revolution , cremation could only take place on an outdoor, open pyre; the alternative was burial . In the 19th century, the development of new furnace technology and contact with cultures that practiced cremation led to its reintroduction in the Western world . The organized movement to instate cremation as
246-412: 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
328-531: 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
410-713: 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 ,
492-444: 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
574-521: A cremator heated by concentrated solar energy . Another new design starting to find use in India, where wood is traditionally used for cremation, is a cremator based around a wood gas fired process. Due to the manner in which the wood gas is produced, such crematories use only a fraction of the required wood; and according to multiple sources, have far less impact on the environment than traditional natural gas or fuel oil processes. A typical unit contains
656-428: 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
738-583: 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
820-445: 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
902-434: 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
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#1732798044748984-412: 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
1066-440: A primary and secondary combustion chamber. These chambers are lined with a refractory brick designed to withstand the high temperatures. The primary chamber contains the body – one at a time usually contained in some type of combustible casket or container. This chamber has at least one burner to provide the heat which vaporizes the water content of the body and aids in combustion of the organic portion. A large door exists to load
1148-493: A result of dental amalgam ). Much of this technology is borrowed from the waste incineration industry on a scaled-down basis. With the rise in the use of cremation in Western nations where amalgam has been used liberally in dental restorations, mercury has been a growing concern. 900 °C (1,650 °F) The application of computer control has allowed cremators to be more automated, in that temperature and oxygen sensors within
1230-534: 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
1312-453: 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
1394-477: 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
1476-451: A very large amount of thermal energy . A 68 kg (150 lbs) body which contains 65% water will require 100 MJ of thermal energy before any combustion will take place. 100 MJ is approximately equivalent to 3 m (105 ft ) of natural gas, or 3 liters of fuel oil (0.8 US gallons). Additional energy is necessary to make up for the heat capacity ("preheating") of the furnace, fuel burned for emissions control, and heat losses through
1558-508: A viable method for body disposal began in the 1870s. In 1869 the idea was presented to the Medical International Congress of Florence by Professors Coletti and Castiglioni "in the name of public health and civilization". In 1873, Professor Paolo Gorini of Lodi and Professor Lodovico Brunetti of Padua published reports or practical work they had conducted. A model of Brunetti's cremating apparatus, together with
1640-672: 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
1722-636: 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
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#17327980447481804-416: 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
1886-403: 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
1968-403: 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
2050-405: 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
2132-408: 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
2214-703: Is now administered by the Southern Metropolitan Cemeteries Trust, which manages nine cemeteries in all, including the Melbourne General Cemetery , St Kilda Cemetery and Dandenong Community Cemetery. The Botanical Cemetery contains the war graves of 146 Commonwealth service personnel, nearly 50 from World War I and nearly 100 from World War II. The Commonwealth War Graves Commission (CWGC) commemorates 67 Commonwealth service personnel cremated at Springvale Crematorium whose ashes remain here. Within two acres of
2296-691: 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
2378-551: 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
2460-547: 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
2542-655: 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
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2624-514: The World War II with the " final solutions to the Jewish question ", crematoria were widely used for the disposal of corpses. The most technically advanced cremation ovens were those developed by the company “ Topf and Sons ” from Erfurt . While a crematorium can be any place containing a cremator, modern crematoria are designed to serve a number of purposes. As well as being a place for
2706-599: 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
2788-419: 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
2870-445: 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
2952-475: 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
3034-626: 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
3116-481: 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
3198-608: 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
3280-724: The Botanical Cemetery, beyond the crematorium, lies the CWGC's Springvale War Cemetery , created in World War II, where are buried 607 Commonwealth service personnel and 4 Dutch personnel. It contains a Cross of Sacrifice unveiled in 1948. In the form of bronze plaques on the rear wall of the shelter behind the Cross is the Victoria Cremation Memorial to 75 Commonwealth service personnel cremated within
3362-470: 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
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3444-533: The State of Victoria whose ashes were laid where a memorial could not be sited. Crematorium A crematorium or crematory is a venue for the cremation of the dead . Modern crematoria contain at least one cremator (also known as a crematory , retort or cremation chamber ), a purpose-built furnace. In some countries a crematorium can also be a venue for open-air cremation . In many countries, crematoria contain facilities for funeral ceremonies, such as
3526-574: The West opened in Milan in 1876. By the end of the 19th century, several countries had seen their first crematorium open. Golders Green Crematorium was built from 1901 to 1928 in London and pioneered two features that would become common in future crematoria: the separation of entrance and exit, and a garden of remembrance. In the extermination camps created by the authorities of Nazi Germany during
3608-401: 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
3690-436: 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
3772-471: 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
3854-437: The body container. Temperature in the primary chamber is typically between 760–980 °C (1,400–1,800 °F). Higher temperatures speed cremation but consume more energy, generate more nitric oxide , and accelerate spalling of the furnace's refractory lining. The secondary chamber may be at the rear or above the primary chamber. A secondary burner(s) fires into this chamber, oxidizing any organic material which passes from
3936-494: 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
4018-472: The building. 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
4100-652: The cemetery. The first cremation took place at Springvale in April 1905. According to the Southern Metropolitan Cemeteries Trust, here have been approximately 473,000 cremations and 162,000 burials at the Springvale Botanical Cemetery. In 2006, the cemetery was renamed the Springvale Botanical Cemetery to reflect its increasing botanical significance, which includes original plantings of two bunya pines , palms and gums. It
4182-455: 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
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#17327980447484264-485: The cremator. To provide a substitute for the traditional ritual of seeing the coffin descend into a grave, they incorporate a mechanism for removing the coffin from sight. On the other hand, in Japan, mourners will watch the coffin enter the cremator, then will return after the cremation for the custom of picking the bones from the ashes. While open outdoor pyres were used in the past and are often still used in many areas of
4346-405: The direct application of flame to the body. Coal, coke , and wood were used in the past, heating the chambers from below (like a cooking pot). This resulted in an indirect heat and prevented mixing of ash from the fuel with ash from the body. The term retort when applied to cremation furnaces originally referred to this design. There has been interest, mainly in developing nations, to develop
4428-452: 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
4510-474: The exhaust gases from the furnace are pumped into a chamber containing bricks, where heat is transferred from the gases to the bricks. The flow of the furnace is then reversed so that fuel and air pass through the chamber and are heated by the bricks. Through this method, an open-hearth furnace can reach temperatures high enough to melt steel , and this process made cremation an efficient and practical proposal. Charles's nephew, Carl Friedrich von Siemens perfected
4592-648: 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
4674-579: 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
4756-513: 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
4838-443: The funeral chapel, or other facilities or for distribution into local district heating networks has arisen in recent years. Such heat recovery efforts have been viewed in both a positive and negative light by the public. 760–980 °C (1,400–1,800 °F) . In addition, filtration systems ( baghouses ) are being applied to crematories in many countries. Activated carbon adsorption is being considered for mercury abatement (as
4920-599: 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
5002-442: The insulation and in the flue gases. As a result, crematories are most often heated by burners fueled by natural gas . LPG (propane/butane) or fuel oil may be used where natural gas is not available. These burners can range in power from 150 to 400 kilowatts (0.51 to 1.4 million British thermal units per hour). Crematories heated by electricity also exist in India, where electric heating elements bring about cremation without
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#17327980447485084-439: 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
5166-450: 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
5248-446: 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
5330-483: The practical but dignified disposal of dead bodies, they must also serve the emotional and spiritual needs of the mourners. The design of a crematorium is often heavily influenced by the funeral customs of its country. For example, crematoria in the United Kingdom are designed with a separation between the funeral and cremation facilities, as it is not customary for mourners to witness the coffin being placed in
5412-433: The primary chamber. This acts as a method of pollution control to eliminate the emission of odors and smoke. The secondary chamber typically operates at a temperature greater than 900 °C (1,650 °F). The flue gases from the secondary chamber are usually vented to the atmosphere through a refractory-lined flue. They are at a very high temperature, and interest in recovering this thermal energy e.g. for space heating of
5494-449: 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
5576-707: 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
5658-426: 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
5740-700: The resulting ashes, was exhibited at the Vienna Exposition in 1873 and attracted great attention, including that of Sir Henry Thompson , a surgeon and Physician to the Queen Victoria , who "returned home to become the first and chief promoter of cremation in England". Meanwhile, Sir Charles William Siemens had developed his regenerative furnace in the 1850s. His furnace operated at a high temperature by using regenerative preheating of fuel and air for combustion . In regenerative preheating,
5822-401: 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
5904-561: 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
5986-561: 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
6068-419: The unit along with pre-programmed algorithms based upon the weight of the deceased allow the unit to operate with less user intervention. Such computer systems may also streamline recordkeeping requirements for tracking, environmental, and maintenance purposes. The time to carry out a cremation can vary from 70 minutes to 210 minutes. Cremators used to run on timers (some still do) and one would have to determine
6150-525: 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
6232-499: The use of this furnace for the incineration of organic material at his factory in Dresden . The radical politician, Sir Charles Wentworth Dilke , took the corpse of his dead wife there to be cremated in 1874. The efficient and cheap process brought about the quick and complete incineration of the body and was a fundamental technical breakthrough that finally made industrial cremation a practical possibility. The first crematorium in
6314-400: The weight of the body therefore calculating how long the body has to be cremated for and set the timers accordingly. Other types of crematories merely have a start and a stop function for the cremation displayed on the user interface. The end of the cremation must be judged by the operator who in turn stops the cremation process. As an energy-saving measure, some cremators provide heating for
6396-457: The world today, notably India, most cremation in industrialized nations takes place within enclosed furnaces designed to maximize use of the thermal energy consumed while minimizing the emission of smoke and odors. Video for example-how a crematorium works A human body usually contains a negative caloric value, meaning that energy is required to combust it. This is a result of the high water content; all water must be vaporized which requires
6478-718: 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
6560-509: 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
6642-438: 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
6724-757: 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
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