v • d • e Iron alloy phases
Austenite (γ-iron; hard) Bainite Martensite Cementite (iron carbide; Fe3C) Ledeburite (ferrite - cementite eutectic, 4. Iron (ˈаɪɚn is a Chemical element with the symbol Fe (ferrum and Atomic number 26 An alloy is a Solid solution or Homogeneous mixture of two or more elements, at least one of which is a Metal, which itself has Austenite (or gamma phase iron is a metallic non-magnetic solid solution of Iron and an Alloying element Bainite is a Phase that exists in Steel Microstructures after certain Heat treatments First described by Davenport E Steel 035 water quenchedpng|thumb|200px|035%C Steel water-quenched from 870°C]] Martensite, named after the German metallurgist Adolf Martens (1850–1914 Cementite or iron carbide is a Chemical compound with the formula Fe3C (or Fe2CFe and an Orthorhombic crystal structure In iron and steel Metallurgy, ledeburite is the Eutectic that results when some forms of molten Steel solidify 3% carbon) Ferrite (α-iron, δ-iron; soft) Pearlite (88% ferrite, 12% cementite) Spheroidite
Types of steel
Carbon steel (≤2. Ferrite or alpha iron ( α-Fe) is a Materials science term for Iron, or a Solid solution with iron as the main constituent with a Pearlite is a two-phased, lamellar (or layered structure composed of alternating layers of alpha-ferrite (88 wt% and Cementite (12% that occurs Carbon steel, also called plain carbon steel, is Steel where the main alloying constituent is Carbon. Carbon steel, also called plain carbon steel, is Steel where the main alloying constituent is Carbon. 1% carbon; low alloy) Stainless steel (steel with chromium) HSLA steel (high strength low alloy) Tool steel (very hard)
Other iron-based materials
Cast iron (>2. In Metallurgy, stainless steel is defined as a Steel Alloy with a minimum of 11 High strength low alloy ( HSLA) steel is a type of Steel alloy that provides better mechanical properties or greater resistance to corrosion than Carbon Tool steel refers to a variety of Carbon and Alloy Steels that are particularly well-suited to be made into Tools Their suitability comes from Cast iron usually refers to grey cast iron, but identifies a large group of Ferrous Alloys which solidify with a Eutectic. 1% carbon) Wrought iron (contains slag) Ductile iron

Steel is an alloy consisting mostly of iron, with a carbon content between 0. An alloy is a Solid solution or Homogeneous mixture of two or more elements, at least one of which is a Metal, which itself has Iron (ˈаɪɚn is a Chemical element with the symbol Fe (ferrum and Atomic number 26 Carbon (kɑɹbən is a Chemical element with the symbol C and its Atomic number is 6 2 and 2. 04% by weight (C:1000–10,8. Carbon (kɑɹbən is a Chemical element with the symbol C and its Atomic number is 6 67Fe), depending on grade. Iron (ˈаɪɚn is a Chemical element with the symbol Fe (ferrum and Atomic number 26 Carbon is the most cost-effective alloying material for iron, but various other alloying elements are used such as manganese, chromium, vanadium, and tungsten. Manganese (ˈmæŋgəniːz is a Chemical element, designated by the symbol Mn. Chromium (ˈkroʊmiəm is a Chemical element which has the symbol Cr and Atomic number 24 Vanadium (vəˈneɪdiəm is a Chemical element that has the symbol V and Atomic number 23 Tungsten (ˈtʌŋstən also known as wolfram (/ˈwʊlfrəm/ is a Chemical element that has the symbol W and Atomic number 74 ^[1] Carbon and other elements act as a hardening agent, preventing dislocations in the iron atom crystal lattice from sliding past one another. In Materials science, a dislocation is a Crystallographic defect, or irregularity within a Crystal structure. In Mineralogy and Crystallography, a crystal structure is a unique arrangement of Atoms in a Crystal. Varying the amount of alloying elements and form of their presence in the steel (solute elements, precipitated phase) controls qualities such as the hardness, ductility and tensile strength of the resulting steel. Hardness refers to various properties of Matter in the Solid phase that give it high resistance to various kinds of shape change when Force Ductility is a mechanical property used to describe the extent to which materials can be deformed plastically or "stretched" into "wires" without Tensile strength \sigma_{UTS} or S_U is the Stress at which a material breaks or permanently deforms Steel with increased carbon content can be made harder and stronger than iron, but is also more brittle. The maximum solubility of carbon in iron (in austenite region) is 2. Austenite (or gamma phase iron is a metallic non-magnetic solid solution of Iron and an Alloying element 14% by weight, occurring at 1149 °C; higher concentrations of carbon or lower temperatures will produce cementite. The Celsius Temperature scale was previously known as the centigrade scale. Cementite or iron carbide is a Chemical compound with the formula Fe3C (or Fe2CFe and an Orthorhombic crystal structure Alloys with higher carbon content than this are known as cast iron because of their lower melting point and castability. Cast iron usually refers to grey cast iron, but identifies a large group of Ferrous Alloys which solidify with a Eutectic. ^[1] Steel is also to be distinguished from wrought iron containing only a very small amount of other elements, but containing 1–3% by weight of slag in the form of particles elongated in one direction, giving the iron a characteristic grain. QtubIronPillarJPG|thumb|right| Iron pillar at Delhi India containing 98% wrought iron]] Wrought iron is commercially pure Iron. Slag is the By-product of Smelting Ore to purify Metals They can be considered to be a mixture of metal Oxides however It is more rust-resistant than steel and welds more easily. Rust is a general term for a series of Iron oxides, usually red oxides formed by the reaction of Iron with Oxygen in the presence of water or air It is common today to talk about 'the iron and steel industry' as if it were a single entity, but historically they were separate products.

Though steel had been produced by various inefficient methods long before the Renaissance, its use became more common after more efficient production methods were devised in the 17th century. The Renaissance (from French Renaissance, meaning "rebirth" Italian: Rinascimento, from re- "again" and nascere With the invention of the Bessemer process in the mid-19th century, steel became a relatively inexpensive mass-produced good. The Bessemer process was the first inexpensive Industrial process for the mass-production of Steel from molten Pig iron. Mass production (also called flow production, repetitive flow production, series production, or serial production) is the production of Further refinements in the process, such as basic oxygen steelmaking, further lowered the cost of production while increasing the quality of the metal. Basic oxygen steelmaking ( BOS BOF Linz-Donawitz-Verfahren LD-converter) is a method of Steelmaking in which carbon-rich molten iron is made into Steel Today, steel is one of the most common materials in the world and is a major component in buildings, tools, automobiles, and appliances. Refrigerator1svg|left|100px]]A major appliance, or domestic appliance, is usually defined as a large Machine which accomplishes some routine housekeeping task which Modern steel is generally identified by various grades of steel defined by various standards organizations. A standards organization, standards body, standards development organization or SDO is any entity whose primary activities are developing coordinating

Contents 1 Material properties 2 History of steelmaking 2.1 Ancient steel 2.2 Wootz steel and Damascus steel 2.3 Early modern steel 2.3.1 Blister steel 2.3.2 Crucible steel 2.4 Modern steelmaking 3 Steel industry 4 Recycling 5 Contemporary steel 6 Modern production methods 7 Uses of steel 7.1 Historically 7.2 Since 1850 7.2.1 Long steel 7.2.2 Flat carbon steel 7.2.3 Stainless steel 8 See also 9 References 10 Further reading 11 External links

Material properties

Iron, like most metals, is not usually found in the Earth's crust in an elemental state. Iron (ˈаɪɚn is a Chemical element with the symbol Fe (ferrum and Atomic number 26 EARTH was a short-lived Japanese vocal trio which released 6 singles and 1 album between 2000 and 2001 In Geology, a crust is the outermost solid shell of a planet or moon ^[2] Iron can be found in the crust only in combination with oxygen or sulfur. Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the Sulfur or sulphur (ˈsʌlfɚ see spelling below) is the Chemical element that has the Atomic number 16 Typical iron-containing minerals include Fe₂O₃—the form of iron oxide found as the mineral hematite, and FeS₂—pyrite (fool's gold). Altogether there are sixteen known Iron Oxides and oxyhydroxides A mineral is a naturally occurring substance formed through geological processes that has a characteristic chemical composition a highly ordered atomic structure and specific Hematite, also spelt hæmatite, is the Mineral form of Iron(III oxide (Fe2O3 one of several Iron oxides ^[3] Iron is extracted from ore by removing the oxygen by combining it with a preferred chemical partner such as carbon. An ore is a volume of rock containing components or Minerals in a mode of occurrence that renders it valuable for mining This process, known as smelting, was first applied to metals with lower melting points. Chemical reduction, or smelting, is a form of Extractive metallurgy. Melting is a process that results in the phase change of a substance from a Solid to a Liquid. Copper melts at just over 1000 °C, while tin melts around 250 °C. Copper (ˈkɒpɚ is a Chemical element with the symbol Cu (cuprum and Atomic number 29 Tin is a Chemical element with the symbol Sn (stannum and Atomic number 50 Cast iron—iron alloyed with greater than 1. 7% carbon—melts at around 1370 °C. All of these temperatures could be reached with ancient methods that have been used for at least 6000 years (since the Bronze Age). The term Bronze Age refers to a period in human cultural development when the most advanced Metalworking (at least in systematic and widespread use included techniques for Since the oxidation rate itself increases rapidly beyond 800 °C, it is important that smelting take place in a low-oxygen environment. Unlike copper and tin, liquid iron dissolves carbon quite readily, so that smelting results in an alloy containing too much carbon to be called steel. ^[4]

Even in the narrow range of concentrations that make up steel, mixtures of carbon and iron can form into a number of different structures, with very different properties; understanding these is essential to making quality steel. At room temperature, the most stable form of iron is the body-centered cubic (BCC) structure ferrite or α-iron, a fairly soft metallic material that can dissolve only a small concentration of carbon (no more than 0. The cubic crystal system (or isometric) is a Crystal system where the Unit cell is in the shape of a Cube. Ferrite or alpha iron ( α-Fe) is a Materials science term for Iron, or a Solid solution with iron as the main constituent with a 021 wt% at 910 °C). Above 910 °C ferrite undergoes a phase transition from body-centered cubic to a face-centered cubic (FCC) structure, called austenite or γ-iron, which is similarly soft and metallic but can dissolve considerably more carbon (as much as 2. In Thermodynamics, phase transition or phase change is the transformation of a thermodynamic system from one phase to another The cubic crystal system (or isometric) is a Crystal system where the Unit cell is in the shape of a Cube. Austenite (or gamma phase iron is a metallic non-magnetic solid solution of Iron and an Alloying element 03 wt% carbon at 1154 °C). ^[5] As carbon-rich austenite cools, the mixture attempts to revert to the ferrite phase, resulting in an excess of carbon. One way for carbon to leave the austenite is for cementite to precipitate out of the mix, leaving behind iron that is pure enough to take the form of ferrite, resulting in a cementite-ferrite mixture. Cementite or iron carbide is a Chemical compound with the formula Fe3C (or Fe2CFe and an Orthorhombic crystal structure Precipitation is the formation of a Solid in a Solution during a Chemical reaction. Cementite is a stoichiometric phase with the chemical formula of Fe₃C. Stoichiometry (sometimes called reaction stoichiometry to distinguish it from composition stoichiometry is the Calculation of Quantitative (measurable Cementite forms in regions of higher carbon content while other areas revert to ferrite around it. Self-reinforcing patterns often emerge during this process, leading to a patterned layering known as pearlite (Fe₃C:6. Pearlite is a two-phased, lamellar (or layered structure composed of alternating layers of alpha-ferrite (88 wt% and Cementite (12% that occurs 33Fe) due to its pearl-like appearance, or the similar but less beautiful bainite. A pearl is a hard roundish object produced within the soft tissue (specifically the mantle) of a living shelled Mollusk. Bainite is a Phase that exists in Steel Microstructures after certain Heat treatments First described by Davenport E

Perhaps the most important polymorphic form is martensite, a chemically metastable substance with about four to five times the strength of ferrite. Polymorphism in Materials science is the ability of a solid material to exist in more than one form or Crystal structure Steel 035 water quenchedpng|thumb|200px|035%C Steel water-quenched from 870°C]] Martensite, named after the German metallurgist Adolf Martens (1850–1914 A minimum of 0. 4 wt% of carbon (C:50Fe) is needed to form martensite. When austenite is quenched to form martensite, the carbon is "frozen" in place when the cell structure changes from FCC to BCC. The carbon atoms are much too large to fit in the interstitial vacancies and thus distort the cell structure into a body-centered tetragonal (BCT) structure. Martensite and austenite have an identical chemical composition. As such, it requires extremely little thermal activation energy to form. In Chemistry, activation energy, also called midnight energy, is a term introduced in 1889 by the Swedish scientist Svante Arrhenius, that is defined

The heat treatment process for most steels involves heating the alloy until austenite forms, then quenching the hot metal in water or oil, cooling it so rapidly that the transformation to ferrite or pearlite does not have time to take place. A quench refers to a rapid Cooling. In Polymer chemistry and Materials science, quenching is used to prevent low-temperature processes such as phase Water is a common Chemical substance that is essential for the survival of all known forms of Life. An oil is a substance that is in a viscous Liquid state ( "oily") at ambient temperatures or slightly warmer and is The transformation into martensite, by contrast, occurs almost immediately, due to a lower activation energy.

Martensite has a lower density than austenite, so that transformation between them results in 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. Physical compression is the result of the subjection of a material to Compressive stress, resulting in reduction of Volume. In Physics String Tension is the magnitude of the pulling force exerted by a string cable chain or similar object on another object If quenching is done improperly, these internal stresses can cause a part to shatter as it cools; at the very least, they cause internal work hardening and other microscopic imperfections. Work hardening, strain hardening, or cold work is the strengthening of a material by macroscopically speaking plastic deformation (which has the It is common for quench cracks to form when water quenched, although they may not always be visible. ^[6]

At this point, if the carbon content is high enough to produce a significant concentration of martensite, the result is an extremely hard but very brittle material. Often, steel undergoes further heat treatment at a lower temperature to destroy some of the martensite (by allowing enough time for cementite etc. to form) and help settle the internal stresses and defects. This softens the steel, producing a more ductile and fracture-resistant metal. Because time is so critical to the end result, this process is known as tempering, which forms tempered steel. Tempering is a Heat treatment technique for metals and Alloys In Steels tempering is done to "toughen" the metal by transforming brittle ^[7]

Other materials are often added to the iron/carbon mixture to tailor the resulting properties. Nickel and manganese in steel add to its tensile strength and make austenite more chemically stable, chromium increases hardness and melting temperature, and vanadium also increases hardness while reducing the effects of metal fatigue. Nickel (ˈnɪkəl is a metallic Chemical element with the symbol Ni and Atomic number 28 Manganese (ˈmæŋgəniːz is a Chemical element, designated by the symbol Mn. Chromium (ˈkroʊmiəm is a Chemical element which has the symbol Cr and Atomic number 24 Vanadium (vəˈneɪdiəm is a Chemical element that has the symbol V and Atomic number 23 Large amounts of chromium and nickel (often 18% and 8%, respectively) are added to stainless steel so that a hard oxide forms on the metal surface to inhibit corrosion. In Metallurgy, stainless steel is defined as a Steel Alloy with a minimum of 11 Passivation is the process of making a material "passive" in relation to another material prior to using the materials together Tungsten interferes with the formation of cementite, allowing martensite to form with slower quench rates, resulting in high speed steel. Tungsten (ˈtʌŋstən also known as wolfram (/ˈwʊlfrəm/ is a Chemical element that has the symbol W and Atomic number 74 High speed steel (often abbreviated HSS, sometimes HS) is a material usually used in the manufacture of machine Tool bits and other cutters On the other hand sulfur, nitrogen, and phosphorus make steel more brittle, so these commonly found elements must be removed from the ore during processing. Sulfur or sulphur (ˈsʌlfɚ see spelling below) is the Chemical element that has the Atomic number 16 Nitrogen (ˈnaɪtɹəʤɪn is a Chemical element that has the symbol N and Atomic number 7 and Atomic weight 14 Phosphorus, (ˈfɒsfərəs is the Chemical element that has the symbol P and Atomic number 15 ^[8]

When iron is smelted from its ore by commercial processes, it contains more carbon than is desirable. To become steel, it must be melted and reprocessed to remove the correct amount of carbon, at which point other elements can be added. Once this liquid is cast into ingots, it usually must be "worked" at high temperature to remove any cracks or poorly mixed regions from the solidification process, and to produce shapes such as plate, sheet, wire, etc. An ingot is a material usually metal that is cast into a shape suitable for further processing It is then heat-treated to produce a desirable crystal structure, and often "cold worked" to produce the final shape. In modern steel making these processes are often combined, with ore going in one end of the assembly line and finished steel coming out the other. An assembly line is a Manufacturing process in which parts (usually Interchangeable parts) are added to a product in a sequential manner using optimally planned These can be streamlined by a deft control of the interaction between work hardening and tempering. Work hardening, strain hardening, or cold work is the strengthening of a material by macroscopically speaking plastic deformation (which has the

History of steelmaking

Main article: History of ferrous metallurgy

Ancient steel

Steel was known in antiquity, and may have been produced by managing the bloomery so that the bloom contained carbon. The history of ferrous metallurgy began far back in Prehistory, most likely with the use of Iron from Meteorites The Smelting of iron in A bloomery is a type of Furnace once widely used for Smelting Iron from its oxides. ^[9] Some of the first steel comes from East Africa, dating back to 1400 BC. ^[10] In the 4th century BC steel weapons like the Falcata were produced in the Iberian peninsula. The falcata is a type of Sword typical of Pre- Roman Hispania (the Iberian Peninsula, modern Spain and Portugal) similar The Chinese of the Han Dynasty (202 BC – 220 AD) created steel by melting together wrought iron with cast iron, gaining an ultimate product of a carbon-intermediate—steel by the 1st century AD. Chinese civilization originated in various city-states along the Yellow River ( valley in the Neolithic era The Han Dynasty ( 206 BC–220 AD followed the Qin Dynasty and preceded the Three Kingdoms in China. QtubIronPillarJPG|thumb|right| Iron pillar at Delhi India containing 98% wrought iron]] Wrought iron is commercially pure Iron. Cast iron usually refers to grey cast iron, but identifies a large group of Ferrous Alloys which solidify with a Eutectic. ^[11][12]

Wootz steel and Damascus steel

Wootz steel was produced in India and Sri Lanka from around 300 BC. Sri Lanka, officially the Democratic Socialist Republic of Sri Lanka ( Sinhalese:, இலங்கை known as Ceylon before 1972 is an Island Along with their original methods of forging steel, the Chinese had also adopted the production methods of creating Wootz steel, an idea imported from India to China by the 5th century AD. Wootz is a Steel characterized by a pattern of bands or sheets of micro Carbides within a tempered Martensite or Pearlite matrix India, officially the Republic of India (भारत गणराज्य inc-Latn Bhārat Gaṇarājya; see also other Indian languages) is a country ^[13] This early steel-making method employed the use of a wind furnace, blown by the monsoon winds and produced almost pure steel. ^[14] Also known as Damascus steel, wootz is famous for its durability and ability to hold an edge. Damascus steel is a hot- forged Steel used in Middle Eastern Swordmaking from about 1100 to 1700 AD Sharpening is the process of creating or refining a sharp edge of appropriate shape on a tool or implement designed for cutting It was originally created from a number of different materials including various trace elements. In Analytical chemistry, a trace element is an element in a sample that has an average Concentration of less than 100 Parts per million atoms It was essentially a complicated alloy with iron as its main component. Recent studies have suggested that carbon nanotubes were included in its structure, which might explain some of its legendary qualities, though given the technology available at that time, they were produced by chance rather than by design. See also Graphene, Buckypaper Carbon nanotubes (CNTs are Allotropes of carbon with a nanostructure that can have a length-to-diameter ^[15]

Crucible steel was produced in Merv by 9th to 10th century AD. Crucible steel describes a number of different techniques for making Steel Alloy by slowly heating and cooling pure Iron and Carbon (typically Merv ( Russian: Мерв from Persian: مرو Marv, sometimes transliterated Marw or Mary; cf

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 utilized partial decarbonization via repeated forging under a cold blast. The Song Dynasty ( Wade-Giles: Sung Ch'ao was a ruling dynasty in China between 960&ndash1279 CE it succeeded the Five Dynasties and Ten Kingdoms ^[16]

Early modern steel

Blister steel

Main article: Cementation process

Blister steel, produced by the cementation process was first made in Italy in the early 16th century CE and soon after introduced to England. The cementation process is an obsolete technique for making Steel by Carburization of Iron. The cementation process is an obsolete technique for making Steel by Carburization of Iron. It was produced by Sir Basil Brooke at Coalbrookdale during the 1610s. Sir Basil Brooke ( 1576 &ndash 1646) English Metallurgist and Recusant, inherited the manor of Madeley from Coalbrookdale is a side valley of the Ironbridge Gorge in the borough of Telford and Wrekin and ceremonial county of Shropshire, England The raw material for this were bars of wrought iron. QtubIronPillarJPG|thumb|right| Iron pillar at Delhi India containing 98% wrought iron]] Wrought iron is commercially pure Iron. During the 17th century it was realised that the best steel came from oregrounds iron from a region of Sweden, north of Stockholm. The English term Oregrounds iron takes its name from the small Swedish city of Öregrund. "Sverige" redirects here For other uses see Sweden (disambiguation and Sverige (disambiguation. ('stɔkhɔlm is Sweden 's Capital and its largest City. It is the site of the national Swedish government, the parliament, and the This was still the usual raw material in the 19th century, almost as long as the process was used. ^[17][18]

Crucible steel

Main article: Crucible steel

Crucible steel is steel that has been melted in a crucible rather than being forged, with the result that it is more homogeneous. Crucible steel describes a number of different techniques for making Steel Alloy by slowly heating and cooling pure Iron and Carbon (typically A crucible is a cup-shaped piece of laboratory object Laboratory equipment used to contain Chemical compounds when heating them to very high Temperatures Forging is the term for shaping metal by using localized compressive forces Most previous furnaces could not reach high enough temperatures to melt the steel. The early modern crucible steel industry resulted from the invention of Benjamin Huntsman in the 1740s. Benjamin Huntsman ( 4 June 1704 – 20 June 1776) was an English inventor and manufacturer of Crucible steel. Blister steel (made as above) was melted in a crucible in a furnace, and cast (usually) into ingots. ^[18]

Modern steelmaking

Main article: Steelmaking

See also: History of the modern steel industry

The modern era in steelmaking began with the introduction of Henry Bessemer's Bessemer process in 1858^[19]. Steelmaking is the second step in producing Steel from Iron ore. The history of the modern steel industry began in the late 1850s, but since then Steel has been basic to the world's industrial economy Steelmaking is the second step in producing Steel from Iron ore. Sir Henry Bessemer ( January 19, 1813 – March 15, 1898) English Engineer and Inventor. The Bessemer process was the first inexpensive Industrial process for the mass-production of Steel from molten Pig iron. This enabled steel to be produced in large quantities cheaply, so that mild steel is now used for most purposes for which wrought iron was formerly used. Carbon steel, also called plain carbon steel, is Steel where the main alloying constituent is Carbon. ^[20] This was only the first of a number of methods of steel production. The Gilchrist-Thomas process (or basic Bessemer process) was an improvement to the Bessemer process, lining the converter with a basic material to remove phosphorus. Another was the Siemens-Martin process of open hearth steelmaking, which like the Gilchrist-Thomas process complemented, rather than replaced, the original Bessemer process. Open hearth furnaces are one of a number of kinds of Furnace where excess carbon and other impurities are burnt out of Pig iron to produce steel. ^[18]

These were rendered obsolete by the Linz-Donawitz process of basic oxygen steelmaking, developed in the 1950s, and other oxygen steelmaking processes. Basic oxygen steelmaking ( BOS BOF Linz-Donawitz-Verfahren LD-converter) is a method of Steelmaking in which carbon-rich molten iron is made into Steel ^[21]

Steel industry

Because of the critical role played by steel in infrastructural and overall economic development, the steel industry is often considered to be an indicator of economic progress.

The economic boom in China and India has caused a massive increase in the demand for steel in recent years. China ( Wade-Giles ( Mandarin) Chung¹kuo² is a cultural region, an ancient Civilization, and depending on perspective a National India, officially the Republic of India (भारत गणराज्य inc-Latn Bhārat Gaṇarājya; see also other Indian languages) is a country Between 2000 and 2005, world steel demand increased by 6%. Since 2000, several Indian^[22] and Chinese steel firms have risen to prominence like Tata Steel (which bought Corus Group in 2007), Shanghai Baosteel Group Corporation and Shagang Group. Tata Steel, formerly known as TISCO (Tata Iron and Steel Company Limited) is the world's 5th largest and India's largest steel company with an annual crude steel Corus is a subsidiary of Tata Steel, part of India 's Tata Group and world's fifth largest steel producer, headquartered in London, For another steel company headquartered in Baotou Inner Mongolia please refer to Baotou Steel. Shagang Group or Jiangsu Shagang Group is located in ZhangJiagang City an Economic Development Zone of the Yangtze River. ArcelorMittal is however the world's largest steel producer. ArcelorMittal (,,) is the largest steel company in the world with 310000 employees in more than 60 countries This article summarizes the world Steel production by company.

The British Geological Survey reports that in 2005, China was the top producer of steel with about one-third world share followed by Japan, Russia and the USA. The British Geological Survey (BGS is a partly publicly-funded body which aims to advance geoscientific knowledge of the United Kingdom landmass and its Continental

In 2008, steel will be traded as a commodity in the London Metal Exchange. Commodity markets are markets where raw or primary products are exchanged The London Metal Exchange or LME is the Futures exchange with the world's largest market in options and Futures contracts on base and

See also: List of steel producers and Global steel industry trends

Recycling

Steel is the most widely recycled material in North America. This article summarizes the world Steel production by company. The global Steel industry has been going through major changes since 1970 The steel industry has been actively recycling for more than 150 years, in large part because it is economically advantageous to do so. Recycling involves processing used materials into new products in order to prevent the waste of potentially useful materials reduce the consumption of fresh raw materials reduce It is cheaper to recycle steel than to mine iron ore and manipulate it through the production process to form 'new' steel. Iron ores are rocks and Minerals from which Metallic Iron can be economically extracted Steel does not lose any of its inherent physical properties during the recycling process, and has drastically reduced energy and material requirements than refinement from iron ore. The energy saved by recycling reduces the annual energy consumption of the industry by about 75%, which is enough to power eighteen million homes for one year. ^[23] Recycling one ton of steel saves 1,100 kilograms of iron ore, 630 kilograms of coal, and 55 kilograms of limestone. Iron ores are rocks and Minerals from which Metallic Iron can be economically extracted Limestone is a Sedimentary rock composed largely of the Mineral Calcite ( Calcium carbonate: CaCO3 ^[24] 76 million tons of steel were recycled in 2005. ^[23]

In recent years, about three quarters of the steel produced annually has been recycled. However, the numbers are much higher for certain types of products. For example, in both 2004 and 2005, 97. 5% of structural steel beams and plates were recycled. ^[25] Other steel construction elements such as reinforcement bars are recycled at a rate of about 65%. Indeed, structural steel typically contains around 95% recycled steel content, whereas lighter gauge, flat rolled steel contains about 30% reused material.

Because steel beams are manufactured to standardized dimensions, there is often very little waste produced during construction, and any waste that is produced may be recycled. In the fields of Architecture and Civil engineering, construction is a process that consists of the Building or assembling of Infrastructure For a typical 2,000-square-foot (200 m²) two-story house, a steel frame is equivalent to about six recycled cars, while a comparable wooden frame house may require as many as 40–50 trees. Steel frame usually refers to a building technique with a " Skeleton frame" of vertical Steel Columns and horizontal I-beams constructed A tree is a perennial Woody plant. It is most often defined as a woody plant that has many secondary branches supported clear of the ground on a single main stem or ^[23]

Global demand for steel continues to grow, and though there are large amounts of steel existing, much of it is actively in use. As such, recycled steel must be augmented by some first-use metal, derived from raw materials. Commonly recycled steel products include cans, automobiles, appliances, and debris from demolished buildings. Debris (ˈdeɪbriː/ /dɛˈbriː is a word used to describe the remains of something that has been otherwise destroyed A typical appliance is about 65% steel by weight and automobiles are about 66% steel and iron.

While some recycling takes place through the integrated steel mills and the basic oxygen process, most of the recycled steel is melted electrically, either using an electric arc furnace (for production of low-carbon steel) or an induction furnace (for production of some highly-alloyed ferrous products). Steel Mill was one of Bruce Springsteen 's early bands and performed regularly on the Jersey Shore, in Virginia, and also in California from 1969 Basic oxygen steelmaking ( BOS BOF Linz-Donawitz-Verfahren LD-converter) is a method of Steelmaking in which carbon-rich molten iron is made into Steel An electric arc furnace (EAF is a Furnace that heats charged material by means of an Electric arc. An induction furnace is an electrical Furnace in which the heat is applied by Induction heating of a conductive medium (usually a Metal) in a Crucible

Contemporary steel

Modern steels are made with varying combinations of alloy metals to fulfill many purposes. ^[8] Carbon steel, composed simply of iron and carbon, accounts for 90% of steel production. Carbon steel, also called plain carbon steel, is Steel where the main alloying constituent is Carbon. ^[1] High strength low alloy steel has small additions (usually < 2% by weight) of other elements, typically 1. High strength low alloy ( HSLA) steel is a type of Steel alloy that provides better mechanical properties or greater resistance to corrosion than Carbon 5% manganese, to provide additional strength for a modest price increase. Manganese (ˈmæŋgəniːz is a Chemical element, designated by the symbol Mn. ^[26] Low alloy steel is alloyed with other elements, usually molybdenum, manganese, chromium, or nickel, in amounts of up to 10% by weight to improve the hardenability of thick sections. ^[1] Stainless steels and surgical stainless steels contain a minimum of 10% chromium, often combined with nickel, to resist corrosion (rust). In Metallurgy, stainless steel is defined as a Steel Alloy with a minimum of 11 Surgical stainless steel is an specific type of Stainless steel, used in medical applications Chromium (ˈkroʊmiəm is a Chemical element which has the symbol Cr and Atomic number 24 Nickel (ˈnɪkəl is a metallic Chemical element with the symbol Ni and Atomic number 28 Corrosion means the breaking down of essential properties in a material due to Chemical reactions with its surroundings Rust is a general term for a series of Iron oxides, usually red oxides formed by the reaction of Iron with Oxygen in the presence of water or air Some stainless steels are magnetic, while others are nonmagnetic. In Physics, magnetism is one of the Phenomena by which Materials exert attractive or repulsive Forces on other Materials. In Physics, magnetism is one of the Phenomena by which Materials exert attractive or repulsive Forces on other Materials. ^[27]

Some more modern steels include tool steels, which are alloyed with large amounts of tungsten and cobalt or other elements to maximize solution hardening. Tool steel refers to a variety of Carbon and Alloy Steels that are particularly well-suited to be made into Tools Their suitability comes from Cobalt (ˈkoʊbɒlt is a hard lustrous silver-grey Metal, a Chemical element with symbol Co. In Metallurgy, hardening describes techniques to increase the Hardness of a material This also allows the use of precipitation hardening and improves the alloy's temperature resistance. Precipitation hardening, also called age hardening, is a Heat treatment technique used to strengthen Malleable materials including most structural ^[1] Tool steel is generally used in axes, drills, and other devices that need a sharp, long-lasting cutting edge. Other special-purpose alloys include weathering steels such as Cor-ten, which weather by acquiring a stable, rusted surface, and so can be used un-painted. Weathering steel, best-known under the trademark COR-TEN steel is a group of Steel alloys which were developed to obviate the need for painting and form a stable ^[28]

Many other high-strength alloys exist, such as dual-phase steel, which is heat treated to contain both a ferrite and martensic microstructure for extra strength. Dual-phase steel is a high-strength Steel which is heat treated to contain both a Ferrite and martensic microstructure for extra strength ^[29] Transformation Induced Plasticity (TRIP) steel involves special alloying and heat treatments to stabilize amounts of austentite at room temperature in normally austentite-free low-alloy ferritic steels. By applying strain to the metal, the austentite undergoes a phase transition to martensite without the addition of heat. ^[30] Maraging steel is alloyed with nickel and other elements, but unlike most steel contains almost no carbon at all. Maraging steels (a Portmanteau of Martensitic and aging are iron Alloys which are known for possessing superior strength and toughness without losing This creates a very strong but still malleable metal. For malleability in Cryptography, see Malleability (cryptography. ^[31] Twinning Induced Plasticity (TWIP) steel uses a specific type of strain to increase the effectiveness of work hardening on the alloy. ^[32] Eglin Steel uses a combination of over a dozen different elements in varying amounts to create a relatively low-cost metal for use in bunker buster weapons. Eglin Steel ( ES-1) is a high- strength, high-performance low-alloy low-cost Steel, developed for new generation of Bunker buster type bombs A bunker buster is a Bomb designed to penetrate hardened targets or targets buried deep underground Hadfield steel (after Sir Robert Hadfield) or manganese steel contains 12–14% manganese which when abraded forms an incredibly hard skin which resists wearing. Sir Robert Abbott Hadfield (born November 28, 1858, Sheffield; died September 30, 1940, Surrey) was an English metallurgist Manganese (ˈmæŋgəniːz is a Chemical element, designated by the symbol Mn. Examples include tank tracks, bulldozer blade edges and cutting blades on the jaws of life. Continuous tracks are large (modular tracks used on the so-called caterpillar Tanks construction equipment and certain other off-road vehicles ----A bulldozer is a crawler ( Caterpillar tracked Tractor) equipped with a substantial metal plate (known as a blade) used to push large quantities Hydraulic rescue tools are used by emergency rescue personnel to assist Vehicle extrication of crash victims as well as other rescues from small spaces ^[33] A special class of high-strength alloy, the superalloys, retain their mechanical properties at extreme temperatures while minimizing creep. A superalloy, or high-performance alloy, is an Alloy that exhibits excellent mechanical strength and creep resistance at high temperatures good surface Creep is the tendency of a solid material to slowly move or deform permanently under the influence of stresses It occurs as a result of long term exposure to levels of These are commonly used in applications such as jet engine blades where temperatures can reach levels at which most other alloys would become weak. specific --->A jet engine is a Reaction engine that discharges a fast moving jet of Fluid to ^[34]

Most of the more commonly used steel alloys are categorized into various grades by standards organizations. For example, the American Iron and Steel Institute has a series of grades defining many types of steel ranging from standard carbon steel to HSLA and stainless steel. The American Iron and Steel Institute ( AISI) is an association of North American Steel producers ^[35] The American Society for Testing and Materials has a separate set of standards, which define alloys such as A36 steel, the most commonly used structural steel in the United States. ASTM International ( ASTM) originally known as the American Society for Testing and Materials is an international Standards organization that develops and publishes A36 steel is a standard Steel alloy which is a common structural steel used in the United States ^[36]

Though not an alloy, galvanized steel is a commonly used variety of steel which has been hot-dipped or electroplated in zinc for protection against corrosion (rust). Hot-dip galvanizing is a form of Galvanization. It is the process of coating Iron or Steel with a thin Zinc layer by passing the steel Zinc (ˈzɪŋk from Zink is a Metallic Chemical element with the symbol Zn and Atomic number 30 ^[37]

Modern production methods

Blast furnaces have been used for two millennia to produce pig iron, a crucial step in the steel production process, from iron ore by combining fuel, charcoal, and air. A blast furnace is a type of metallurgical Furnace used for Smelting to produce metals generally Iron. Pig iron is the intermediate product of Smelting Iron ore with coke, usually with Limestone as a flux Modern methods use coke instead of charcoal, which has proven to be a great deal more efficient and is credited with contributing to the British Industrial Revolution. Coke is a solid Carbonaceous material derived from Destructive distillation of low-ash low-sulfur Bituminous coal. The Industrial Revolution was a period in the late 18th and early 19th centuries when major changes in agriculture manufacturing and transportation had a profound effect on the ^[38] Once the iron is refined, converters are used to create steel from the iron. During the late 19th and early 20th century there were many widely used methods such as the Bessemer process and the Siemens-Martin process. However, basic oxygen steelmaking, in which pure oxygen is fed to the furnace to limit impurities, has generally replaced these older systems. Basic oxygen steelmaking ( BOS BOF Linz-Donawitz-Verfahren LD-converter) is a method of Steelmaking in which carbon-rich molten iron is made into Steel Electric arc furnaces are a common method of reprocessing scrap metal to create new steel. An electric arc furnace (EAF is a Furnace that heats charged material by means of an Electric arc. They can also be used for converting pig iron to steel, but they use a great deal of electricity (about 440 kWh per metric ton), and are thus generally only economical when there is a plentiful supply of cheap electricity. ^[39]

Uses of steel

Iron and steel are used widely in the construction of roads, railways, infrastructure and buildings. Steel wool or 'wire wool' is a bundle of strands of very fine soft Steel filaments used in finishing and repairing work to polish wood or metal objects as well as for Most large modern structures, such as stadiums and skyscrapers, bridges and airports, are supported by a steel skeleton. A modern stadium (plural stadiums or stadia in English is a place or venue for (mostly outdoor Sports Concerts or other events consisting A skyscraper is a tall continuously habitable Building. There is no official definition or a precise cutoff height above which a building may clearly be classified as a skyscraper Bridges is the plural form of Bridge. People Bridges is the Family name of Alicia Bridges, An airport is a location where Aircraft such as airplanes, Helicopters and blimps take off and land Even those with a concrete structure will employ steel for reinforcing. In addition to widespread use in major appliances and cars (despite growth in usage of aluminium, it is still the main material for car bodies), steel is used in a variety of other construction-related applications, such as bolts, nails, and screws. Refrigerator1svg|left|100px]]A major appliance, or domestic appliance, is usually defined as a large Machine which accomplishes some routine housekeeping task which WikipediaNaming In the fields of Architecture and Civil engineering, construction is a process that consists of the Building or assembling of Infrastructure In Engineering, Woodworking and Construction, a nail is a pin -shaped sharp object of hard Metal, typically Steel, A screw is a shaft with a helical groove or thread formed on its surface and provision at one end to turn the screw ^[40] Other common applications include shipbuilding, pipeline transport, mining, aerospace, white goods (eg. See also Shipbuilding (song. Shipbuilding is the construction of Ships It normally takes place in a specialized facility known as a Pipeline transport is the transportation of goods through a pipe. Mining is the extraction of valuable Minerals or other geological materials from the earth usually (but not always from an Ore body This article is about the field of research and industry for the corporation see The Aerospace Corporation Aerospace comprises the Refrigerator1svg|left|100px]]A major appliance, or domestic appliance, is usually defined as a large Machine which accomplishes some routine housekeeping task which washing machines), heavy equipment (eg. Engineering vehicles, known by the other terms construction Equipment, earth movers heavy equipment or just plain equipment are machines specifically designed to execute bulldozers), office furniture, steel wool, tools, and armour in the form of personal vests or vehicle armour (better known as rolled homogeneous armour in this role). Steel wool or 'wire wool' is a bundle of strands of very fine soft Steel filaments used in finishing and repairing work to polish wood or metal objects as well as for A broader definition of a tool is an entity used to interface between two or more domains that facilitates more effective action of one domain upon the other Armour (or armor) is protective covering most commonly manufactured from metals to prevent damage from being inflicted to an individual or a vehicle through use of direct contact For body armour see Armour, for armoured forces see Armoured warfare, for other uses see Armour (disambiguation. Rolled homogeneous armour, or RHA is a basic type of steel plate used as a baseline to compare the effectiveness of military Vehicle armour.

Historically

Before the introduction of the Bessemer process and other modern production techniques, steel was expensive and was only used where no cheaper alternative existed, particularly for the cutting edge of knives, razors, swords, and other items where a hard, sharp edge was needed. A knife is a handheld sharp-edged instrument consisting of handle attached to a Blade used for cutting It was also used for springs, including those used in clocks and watches. A spring is a flexible elastic object used to store mechanical Energy. ^[18]

Since 1850

With the advent of faster and more efficient steel production methods, steel has been easier to obtain and much cheaper. It has replaced wrought iron for a multitude of purposes. However, the availability of plastics during the later 20th century allowed these materials to replace steel in many products due to their lower cost and weight. Plastic is the general common term for a wide range of synthetic or semisynthetic organic solid materials suitable for the manufacture of industrial products ^[41]

Long steel

• As supports in reinforced concrete
• Wires
• Railroad tracks
• Structural steel in modern buildings and bridges

Flat carbon steel

• The inside and outside body of automobiles, trains, and ships. Reinforced concrete is Concrete in which reinforcement bars (" Rebars quot or fibers have been incorporated to strengthen a material that would otherwise be A wire is a single usually cylindrical, elongated string of drawn Metal. Structural steel is Steel construction Material, a profile, formed with a specific Shape or cross section and certain standards of In Architecture, Construction, Engineering and real estate development the word building may refer to one of the following Any man-made A bridge is a Structure built to span a Gorge, Valley, Road, railroad track, River, Body of water A train is a connected series of vehicles that move along a track ( Permanent way) to transport freight or passengers from one place to another A ship /ʃɪp/ is a large vessel that floats on water Ships are generally distinguished from Boats based on size
• Major appliances
• Magnetic cores

Stainless steel

Main article: Stainless steel

• Cutlery
• Rulers
• Wrist watches
• Surgical equipment

See also

References

Further reading

• Duncan Burn; The Economic History of Steelmaking, 1867-1939: A Study in Competition. Cambridge University Press, 1961 online version
• J. C. Carr and W. Taplin; History of the British Steel Industry Harvard University Press, 1962 online version
• Gernet, Jacques (1982). A History of Chinese Civilization. Cambridge: Cambridge University Press.
• Harukiyu Hasegawa; The Steel Industry in Japan: A Comparison with Britain 1996 online version
• Needham, Joseph (1986). Science and Civilization in China: Volume 4, Part 1 & Part 3. Taipei: Caves Books, Ltd.
• H. Lee Scamehorn; Mill & Mine: The Cf&I in the Twentieth Century University of Nebraska Press, 1992 online version
• Warren, Kenneth, Big Steel: The First Century of the United States Steel Corporation, 1901-2001. (University of Pittsburgh Press, 2001) online review

External links

• Extensive picture gallery of iron and steel production methods in North America and Europe. In German and English.
• International Iron & Steel Institute (IISI)
• steeluniversity.org: Online steel education ressources from IISI and the University of Liverpool

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