A wrought iron railing in Troy, New York

Iron pillar at Delhi, India, containing 98% wrought iron

The microstructure of wrought iron, showing dark slag inclusions in ferrite (iron)

Wrought iron is commercially pure iron. Ductile iron, also called ductile cast iron, spheroidal graphite iron, or nodular cast iron, is a type of Cast iron invented in 1943 by Guard rail, sometimes referred to as guide rail, is a system designed to keep people or vehicles from (in most cases unintentionally straying into dangerous or off-limits areas Troy is a City in New York, US, and the County seat of Rensselaer County. Iron (ˈаɪɚn is a Chemical element with the symbol Fe (ferrum and Atomic number 26 In contrast to steel, it has a very low carbon content. Carbon (kɑɹbən is a Chemical element with the symbol C and its Atomic number is 6 It is a fibrous material due to the slag inclusions (a normal constituent). Slag is the By-product of Smelting Ore to purify Metals They can be considered to be a mixture of metal Oxides however In mineralogy an inclusion is any material that is trapped inside a Mineral during its formation This is also what gives it a "grain" resembling wood, which is visible when it is etched or bent to the point of failure. Wrought iron is tough, malleable, ductile and easily welded. Welding is a fabrication process that joins materials usually Metals or Thermoplastics by causing coalescence.

Examples of items that used to be produced from wrought iron include: rivets, chains, railway couplings, water and steam pipes, raw material for manufacturing of steel, nuts, bolts, horseshoes, handrails, straps for timber roof trusses, boiler tubes, and ornamental ironwork. A rivet is a mechanical Fastener. Before it is installed it consists of a smooth cylindrical shaft with a head on one end A chain is a series of connected links. This article is about the literal physical chain A coupling (or a coupler) is a mechanism for connecting Rolling stock in a train For the various smoking devices see Hookah or Bong. For other uses see Pipe. Uses A Steam engine uses the expansion of steam in order to drive a Piston or Turbine to perform Mechanical work. A nut is a type of Hardware Fastener with a threaded hole Nuts are almost always used opposite a mating bolt to fasten a stack of parts together A horseshoe is a U-shaped item made of metal or of modern synthetic materials nailed or glued to the Hooves of Horses and some other Draught Handrails are railings used on Stairways and Escalators They are designed to be grasped by the hand while ascending or descending the stairs In Architecture and Structural engineering, a truss is a structure comprising one or more triangular units constructed with straight slender members whose Ironwork is any Weapon, artwork, Utensil or architectural feature made of Iron especially used for decoration

Wrought iron is no longer produced on a commercial scale. ^[1] Many products described as wrought iron, such as guard rails, are made of mild steel. Carbon steel, also called plain carbon steel, is Steel where the main alloying constituent is Carbon. ^[1] They retain that description because they were formerly made of wrought iron or have the appearance of wrought iron. True wrought iron is occasionally required for the authentic conservation of historic structures.

Terminology

Wrought iron is so named because it is worked from a bloom of porous iron mixed with slag and other impurities. A bloomery is a type of Furnace once widely used for Smelting Iron from its oxides. The word "wrought" is an archaic past tense form of the verb to work. As irregular past-tense forms in English have historically been phased out over long periods of time, wrought became worked. Wrought iron literally means worked iron.

Wrought iron is a general term for the commodity, but is also used more specifically for finished iron goods, as manufactured by a blacksmith or other smith. blacksmith is a person who creates objects from Iron or Steel by Forging the Metal; i It was used in this narrower sense in British Customs records, such manufactured iron being subject to a higher rate of duty than what might be called "unwrought" iron. See also Kingdom of Great Britain Great Britain (Breatainn Mhòr Prydain Fawr Breten Veur Graet Breetain is the larger of the two main islands Customs is an Authority or agency in a Country responsible for collecting and safeguarding customs duties and for controlling the flow of goods

In the 17th, 18th and 19th centuries, wrought iron went by a wide variety of terms according to its form, origin, or quality.

Form

• Bar iron - iron in bars, which are the usual product of the finery forge, but not necessarily made by that process. Iron tapped from the Blast furnace is Pig iron, and contains significant amounts of Carbon and Silicon. These might be square or flat, and flat bars might be narrow or broad.
• Rod iron - cut from flat bar iron in a slitting mill to provide the raw material for nails. The slitting mill was a Watermill for slitting bars of Iron into rods In Engineering, Woodworking and Construction, a nail is a pin -shaped sharp object of hard Metal, typically Steel,
• Hoop iron - suitable for the hoops of barrels, apparently made by passing rod iron through flat rolls.
• Plate iron - sheets of iron suitable for use as boiler plate. A boiler is a closed vessel in which Water or other Fluid is heated
• Blackplate - sheets of iron, perhaps thinner than plate iron, from the black rolling stage of tinplate production. Tinplate is sheet steel covered with a thin layer of Tin. Before the advent of cheap mild steel the backing metal was iron.
• Voyage iron - narrow flat bar iron, made or cut into bars of a particular weight, a commodity for sale in Africa for the Atlantic slave trade. The Atlantic Slave trade, also known as the transatlantic slave trade, was the trade of African people supplied to the Colonies of the New World The number of bars per ton gradually increased from 70 per ton in the 1660s to 75-80 per ton in 1685 and "near 92 to the ton" in 1731. ^[2]

Origin

• Oregrounds iron - a particularly pure grade of bar iron made ultimately from iron ore from the Dannemora mine in Sweden. The English term Oregrounds iron takes its name from the small Swedish city of Öregrund. Iron ores are rocks and Minerals from which Metallic Iron can be economically extracted "Sverige" redirects here For other uses see Sweden (disambiguation and Sverige (disambiguation. Its most important use was as the raw material for the cementation process of steelmaking. Steelmaking is the second step in producing Steel from Iron ore. ^[3]
• Danks iron - originally iron imported to Great Britain from Danzig (now Gdansk), but in the 18th century more probably the kind of iron (from eastern Sweden) that once came from Danzig. See also Kingdom of Great Britain Great Britain (Breatainn Mhòr Prydain Fawr Breten Veur Graet Breetain is the larger of the two main islands Gdańsk ( Polish pronunciation; 'Danzig', Gduńsk Gedania Dantiscum is the City at the centre of the fourth-largest Metropolitan area in Poland Gdańsk ( Polish pronunciation; 'Danzig', Gduńsk Gedania Dantiscum is the City at the centre of the fourth-largest Metropolitan area in Poland "Sverige" redirects here For other uses see Sweden (disambiguation and Sverige (disambiguation.
• Forest iron - iron from the Forest of Dean, where haematite ore enabled tough iron to be produced. The Forest of Dean is a geographical historical and cultural region in the western part of the County of Gloucestershire, England Hematite, also spelt hæmatite, is the Mineral form of Iron(III oxide (Fe2O3 one of several Iron oxides
• Lukes iron - iron imported from Liège, whose Dutch name is Luik. Liège (ljɛːʒ Older English: Luick, Walloon: Lidje, German: Lüttich; Latin: Leodium, Dutch ^[4]
• Ames iron or amys iron - another variety of iron imported to England from northern Europe. England is a Country which is part of the United Kingdom. Its inhabitants account for more than 83% of the total UK population whilst its mainland Its origin has been suggested to be Amiens, but it seems to have been imported from Flanders in the 15th century and Holland later, suggesting an origin in the Rhine valley. Amiens (amjɛ̃ is a city and commune in northern France, 120 km north of Paris. Flanders (Vlaanderen Flandre Flandern is a geographical region located in parts of present day Belgium, France, and the Netherlands. Holland is a region in the western part of the Netherlands. A maritime and economic power in the 17th century Holland today consists of the Dutch provinces of The Rhine (Rhein Rijn Rhin Reno Rain Rhenus is one of the longest and most important Rivers in Europe at 1320 kilometres (820 mi with an average discharge Its origins remain controversial. ^[4]
• Botolf iron or Boutall iron - from Butow (Pommerania) or Beuthen (Silesia). Bytów (Bütow Bëtowò is a Town in the Middle Pomerania region of northern Poland in the Bytów Lakeland with 16888 inhabitants (2004 Bytom (Beuthen is a City in southern Poland with 188234 inhabitants (2007 Etymology One theory claims that the name Silesia is derived from the Silingi, who were most likely a Vandalic (East Germanic people ^[4]
• Sable iron (or Old Sable) - iron bearing the mark (a sable) of the Demidov family of Russian ironmasters, one of the better brands of Russian iron. SABLE is an XML Markup language used to annotate texts for Speech synthesis. History The Demidov (Деми́довы family also Demidoff, were probably the richest Russian people after the Tsar in the late Russia (Россия Rossiya) or the Russian Federation ( Rossiyskaya Federatsiya) is a transcontinental Country extending An ironmaster is the manager &ndash and usually owner &ndash of a Forge or Blast furnace for the processing of Iron. ^[5]

Quality

• Tough iron - also spelt "tuf".
• Blend iron - made using a mixture of different types of pig iron. Pig iron is the intermediate product of Smelting Iron ore with coke, usually with Limestone as a flux
• Best iron - in the 19th century, iron that had gone through several stages of piling and rolling, might reach the stage of being best iron.
• Marked Bar iron - iron made by members of the Marked Bar Association and marked with the maker's brand mark as a sign of its quality.

Defective quality

• Iron is coldshort (or "coldshear" or "colshire" or "bloodshot"), if it contains phosphorus in excess quantity. It is very brittle when it is cold. It cracks if bent. It may, however, be worked at high temperature. Historically, coldshort iron was considered good enough for nails. In Engineering, Woodworking and Construction, a nail is a pin -shaped sharp object of hard Metal, typically Steel,
  However, the ancient Indian smiths did not add lime to their furnaces; the absence of CaO in the slag, and the deliberate use of wood with high phosphorus content during the smelting, induces a higher P content (> 0. 1%, average 0. 25%) than in modern iron. There is more phosphorus as solid solution throughout the metal than in the slags (one analysis gives 0. 10% in the slags for 18% in the iron itself, for a total P content of 0. 28% in the metal). This high P content and particular repartition are essential factors in the formation of a passive protective film of “misawite” (d-FeOOH), an amorphous iron oxyhydroxide that forms a barrier by adhering next to the interface between metal and rust. From this technology recently “rediscovered” by metallurgists at IIT Kanpur through the study of the Iron Pillar of Delhi, rust-proof iron is at the last stages of being commercialized. The Indian Institute of Technology Kanpur (known as IIT Kanpur or IITK) is one of the Indian Institutes of Technology, set up in the then-industrial The iron pillar of Delhi, India, located in the Qutb complex, is an important testimony of the History of metallurgy in the Indian subcontinent This 1600 years-old rust-proof pillar is also of a remarkable strength, having withstood the impact of a cannon ball in the 18th century. Copper has a similar effect as phosphate regarding the formation of a passive protection film. ^[6][7][8]

• Iron is redshort if it contains sulfur in excess quantity. It has sufficient tenacity when cold, but cracks when bent or finished at a red heat. It is therefore useless for welding or forging.

History

The puddling process of smelting iron ore to make wrought iron from pig iron, the right half of the illustration (not shown) displays men working a blast furnace, Tiangong Kaiwu encyclopedia published in 1637, written by Song Yingxing (1587-1666). A blast furnace is a type of metallurgical Furnace used for Smelting to produce metals generally Iron. An encyclopedia (or '''encyclopædia''') is a comprehensive written Compendium that contains Information on either all branches of Knowledge Song Yingxing ( Traditional Chinese:宋應星 Simplified Chinese:宋应星 Wade Giles: Sung Ying-Hsing; 1587-1666 AD was a Chinese

Overview

Wrought iron has been used for many centuries, and is the "iron" that is referred to throughout western history. The other form of iron, cast iron, was not introduced into Western Europe until the 15th century; even then, due to its brittleness, it could only be used for a limited number of purposes. Throughout much of the Middle Ages iron was produced by the direct reduction of ore in manually operated bloomeries, although waterpower had begun to be employed by 1104. A bloomery is a type of Furnace once widely used for Smelting Iron from its oxides. Hydropower, hydraulic power or water power is power that is derived from the Force or Energy of moving water which may ^[9]

The raw material produced by all indirect processes is pig iron. It has a high carbon content and as a consequence it is brittle and could not be used to make hardware. The osmond process was the first of the indirect processes, developed by 1203, but bloomery production continued in many places. Osmond iron (also spelt osmund and also called osborn was Wrought iron made by a particular process The process depended on the development of the blast furnace, of which medieval examples have been discovered at Lapphyttan, Sweden and in Germany. A blast furnace is a type of metallurgical Furnace used for Smelting to produce metals generally Iron. Lapphyttan in Norberg, Sweden, may be regarded as the Type site for the Medieval Blast Furnace. "Sverige" redirects here For other uses see Sweden (disambiguation and Sverige (disambiguation. Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe.

The bloomery and osmond processes were gradually replaced from the 15th century by finery processes, of which there were two versions, the German and Walloon. They were in turn replaced from the late 18th century by puddling, with certain variants such as the Swedish Lancashire Process. Puddling was an Industrial Revolution means of making iron and Steel. These too are now obsolete, and wrought iron is no longer manufactured commercially.

Bloomery process

Main article: Bloomery

Wrought iron was originally produced by a variety of smelting processes, all described today as bloomeries. A bloomery is a type of Furnace once widely used for Smelting Iron from its oxides. Different forms of bloomery were used at different places and times. The bloomery was charged with charcoal and iron ore and then lit. Charcoal' is the blackish residue consisting of impure Carbon obtained by removing water and other volatile constituents from Animal and Vegetation Air was blown in through a tuyere to heat the bloomery to a temperature somewhat below the melting point of iron. A tuyere is a Tube, Nozzle or Pipe through which Air is blown into a Furnace or Hearth. In the course of the smelt, slag would melt and run out, and carbon monoxide from the charcoal would reduce the ore to iron, which formed a spongy mass. Carbon monoxide, with the chemical formula CO is a colorless odorless tasteless yet highly toxic Gas. The iron remained in the solid state. If the bloomery was allowed to become hot enough to melt the iron, carbon would dissolve into it and form pig or cast iron, but that was not the intention.

After smelting was complete, the bloom was removed, and the process could then be started again. It was thus a batch process, rather than a continuous one. The spongy mass contained iron and also silicate (slag) from the ore; this was iron bloom from which the technique got its name. The bloom had to be forged mechanically to consolidate it and shape it into a bar, expelling slag in the process. ^[10]

During the Middle Ages, water-power was applied to the process, probably initially for powering bellows, and only later to hammers for forging the blooms. However, while it is certain that water-power was used, the details of this remain uncertain. ^[11] This was the culmination of the direct process of ironmaking. It survived in Spain and southern France as Catalan Forges to the mid 19th century, in Austria as the stuckofen to 1775,^[12] and near Garstang in England until about 1770;^[13] it was still in use with hot blast in New York State in the 1880s. Spain () or the Kingdom of Spain (Reino de España is a country located mostly in southwestern Europe on the Iberian Peninsula. This article is about the country For a topic outline on this subject see List of basic France topics. Austria (Österreich ( officially the Republic of Austria (Republik Österreich Garstang is a town parish within the Wyre borough of Lancashire, England. Hot blast refers to the preheating of air blown into a Blast furnace or other metallurgical process New York ( is a state in the Mid-Atlantic and Northeastern regions of the United States and is the nation's third most populous ^[14]

Osmond process

Main article: Osmond process

Osmond iron consisted of balls of wrought iron, produced by melting pig iron and catching the droplets on a staff, which was spun in front of a blast of air so as to expose as much of it as possible to the air and oxidise its carbon content. Osmond iron (also spelt osmund and also called osborn was Wrought iron made by a particular process Osmond iron (also spelt osmund and also called osborn was Wrought iron made by a particular process ^[15] The resultant ball was often forged into bar iron in a hammer mill.

Finery process

Main article: Finery forge

In the 15th century, the blast furnace spread into what is now Belgium and was improved. Iron tapped from the Blast furnace is Pig iron, and contains significant amounts of Carbon and Silicon. The Kingdom of Belgium is a Country in northwest Europe. It is a founding member of the European Union and hosts its headquarters as well as those From there, it spread via the Pays de Bray on the boundary of Normandy and then to the Weald in England. Normandy (Normandie Norman: Normaundie) is a geographical region corresponding to the former Duchy of Normandy. The Weald (wɪəld is the name given to a physiographic area in south-east England situated between the parallel Chalk Escarpments of the North England is a Country which is part of the United Kingdom. Its inhabitants account for more than 83% of the total UK population whilst its mainland With it, the finery forge spread. These remelted the pig iron and (in effect) burnt out the carbon, producing a bloom, which was then forged into a bar iron. If rod iron was required, a slitting mill was used. The slitting mill was a Watermill for slitting bars of Iron into rods

The finery process existed in two slightly different forms. In Great Britain, France, and parts of Sweden, only the Walloon process was used. See also Kingdom of Great Britain Great Britain (Breatainn Mhòr Prydain Fawr Breten Veur Graet Breetain is the larger of the two main islands This article is about the country For a topic outline on this subject see List of basic France topics. "Sverige" redirects here For other uses see Sweden (disambiguation and Sverige (disambiguation. This employed two different hearths, a finery hearth for fining the iron and a chafery hearth for reheating it in the course of drawing the bloom out into a bar. The finery always burnt charcoal, but the chafery could be fired with mineral coal, since its impurities would not harm the iron when it was in the solid state. On the other hand, the German process, used in Germany, Russia, and most of Sweden used a single hearth for all stages. Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe. Russia (Россия Rossiya) or the Russian Federation ( Rossiyskaya Federatsiya) is a transcontinental Country extending "Sverige" redirects here For other uses see Sweden (disambiguation and Sverige (disambiguation. ^[16]

The introduction of coke for use in the blast furnace by Abraham Darby in 1709 (or perhaps others a littler earlier) initially had little effect on wrought iron production. Coke is a solid Carbonaceous material derived from Destructive distillation of low-ash low-sulfur Bituminous coal. A blast furnace is a type of metallurgical Furnace used for Smelting to produce metals generally Iron. Abraham Darby ( April 14, 1678 &ndash May 5, 1717) was the first and most famous of three generations with that name in an Only in the 1750s was coke pig iron used on any significant scale as the feedstock of finery forges. However, charcoal continued to be the fuel for the finery.

Potting and Stamping

From the late 1750s, ironmasters began to develop processes for making bar iron without charcoal. An ironmaster is the manager &ndash and usually owner &ndash of a Forge or Blast furnace for the processing of Iron. There were a number of patented processes for this, which are referred to today as potting and stamping. The earliest were developed by John Wood of Wednesbury and his brother Charles Wood of Low Mill at Egremont, patented in 1763. Wednesbury is a Market town in England 's Black Country, part of the Sandwell metropolitan borough in West Midlands, near the ^[17] Another was developed for the Coalbrookdale Company by the Cranage brothers. Coalbrookdale is a side valley of the Ironbridge Gorge in the borough of Telford and Wrekin and ceremonial county of Shropshire, England ^[18] Another important one was that of John Wright and Joseph Jesson of West Bromwich. West Bromwich ( is a town within the Metropolitan Borough of Sandwell, in the West Midlands, England ^[19]

Puddling process

Schematic drawing of a puddling furnace

Main article: Puddling (metallurgy)

A number of processes for making wrought iron without charcoal were devised as the Industrial Revolution began during the latter half of the 18th century. Puddling was an Industrial Revolution means of making iron and Steel. 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 The most successful of these was puddling, using a puddling furnace (a variety of the reverberatory furnace). A reverberatory furnace is a metallurgical or process Furnace that isolates the material being processed from contact with the Fuel, but not from contact This was invented by Henry Cort in 1784. Henry Cort (1740 &ndash May 23 1800) was an English Ironmaster. ^[20] It was later improved by others including Joseph Hall. Joseph Hall 1789 - 1862, the inventor of 'Wet Puddling' was born in 1789 and apprenticed in 1806 as a puddler to use Henry Cort 's puddling process In this type of furnace, the metal does not come into contact with the fuel, and so is not contaminated by impurities in it. The flame from the fire is reverberated or sent back down onto the metal on the fire bridge of the furnace.

Unless the raw material used is white cast iron, the pig iron or other raw material first had to be refined into refined iron or finers metal. Pig iron is the intermediate product of Smelting Iron ore with coke, usually with Limestone as a flux This would be done in a refinery where raw coal is used to remove silicon and convert carbon from a graphitic form to a combined form. Silicon (ˈsɪlɪkən or /ˈsɪlɪkɒn/ silicium is the Chemical element that has the symbol Si and Atomic number 14

This metal was placed into the hearth of the puddling furnace where it was melted. The hearth was lined with oxidizing agents such as haematite and iron oxide. Hematite, also spelt hæmatite, is the Mineral form of Iron(III oxide (Fe2O3 one of several Iron oxides ^[21] This mixture is subjected to a strong current of air and stirred with long bars, called puddling bars or rabbles,^[22][23] through working doors. ^[24] The air, stirring, and "boiling" action of the metal help the oxidizing agents to oxidize the impurities and carbon out of the pig iron to their maximum capability. As the impurities oxidize, the retaining material solidifies into spongy wrought iron balls, called puddle balls. ^[21]

Shingling

Main article: Shingling (metallurgy)

There is still some slag left in the puddle balls so while they are still hot they must be shingled,^[25] to remove the remaining slag and cinder. Shingling was a stage in the production of bar iron or Steel, in the finery and puddling processes ^[25][21] It may be achieved by forging the balls under a power hammer or by squeezing the bloom in a squeezing machine. The material obtained at the end of shingling is known as bloom and it is still in red-hot condition. ^[25] The blooms are not useful in this form so they must be rolled into a final product.

Sometimes European ironworks would skip this step completely and roll the puddle balls. The only drawback to this is that the edges of the rough bars are not as well compressed so when the rough bar is reheated the edges may separate and be lost into the furnace. ^[25]

Rolling

Main article: Rolling mill

The bloom is passed through grooved rollers and flat bars were produced. A rolling mill is a Machine or Factory for shaping Metal by passing it between a pair of Work rolls. These bars of wrought iron were of poor quality, called muck bars,^[25][26] or puddle bars. ^[21] To improve the quality of wrought iron, these bars were cut up, piled, and tied together by wires, a process known as faggoting, or piling. ^[25] They were then reheated and rolled again in merchant rolls. This process may be repeated several times to get wrought iron of desired quality. Wrought iron that has been rolled multiple times is called merchant bars or merchant iron. ^[23][27]

Lancashire process

The advantage of puddling was that it used coal, not charcoal as fuel. However this was little advantage in Sweden, which lacks coal. "Sverige" redirects here For other uses see Sweden (disambiguation and Sverige (disambiguation. Gustaf Ekman observed charcoal fineries at Ulverstone, which were quite different from any in Sweden. Ulverstone is a town on the northwest coast of Tasmania, Australia. After his return to Sweden in the 1830s, he experimented and developed a process similar to puddling but using forewood and charcoal, which was widely adopted in the Bergslagen in the following decades. Bergslagen ( Swedish for "Mountain's Law" is a historically culturally and linguistically distinct mining district located north of Lake Mälaren in northern ^[28]

The Aston process

In 1925, James Aston of the United States developed a process for manufacturing wrought iron quickly and economically. James "Jack" Aston ( 1 July 1877 – February 1934 was an English professional footballer born in Walsall, Staffordshire The United States of America —commonly referred to as the It involves taking molten steel from a Bessemer converter and pouring it into cooler liquid slag. The Bessemer process was the first inexpensive Industrial process for the mass-production of Steel from molten Pig iron. The temperature of the steel is about 1500 °C and the liquid slag is maintained at approximately 1200 °C. The molten steel contains a large amount of dissolved gases so when the liquid steel hits the cooler surfaces of the liquid slag the gases are liberated. The molten steel then freezes to yield a spongy mass having a temperature of about 1370 °C. ^[21] This spongy mass must then be finished by being shingled and rolled as described under puddling (above). Shingling was a stage in the production of bar iron or Steel, in the finery and puddling processes A rolling mill is a Machine or Factory for shaping Metal by passing it between a pair of Work rolls. Three to four tons can be converted per batch with this method. ^[21]

Wrought iron is no longer commercially produced. The last wrought iron facility shut down in 1969. ^[1] In the 1960s the price of steel production was dropping due to recycling and even using the Aston process wrought iron production was a labor intensive process. It has been estimated that the production of wrought iron costs approximately twice as much as the production of low carbon steel. ^[1]

Properties

The slag inclusions in wrought iron give it properties not found in other forms of ferrous metal. There are approximately 250,000 inclusions per square inch. ^[1] A fresh fracture shows a clear bluish color with a high silky luster and fibrous appearance.

Wrought iron lacks the carbon content necessary for hardening through heat treatment, but in areas where steel was uncommon or unknown, tools were sometimes cold-worked (hence cold iron) in order to harden them. Second Album by Rock and roll Singer-songwriter near-legend Graham Parker. Cold iron is a poetic and archaic term for Iron, referring to the fact that it feels cold to the touch An advantage of its low carbon content is its excellent weldability. ^[1] Furthermore, sheet wrought iron cannot bend as much as steel sheet metal (when cold worked). ^[29][30][31] Wrought iron can be cast, however there is no engineering advantage, as compared to cast iron; cast iron is much easier to produce, and thus cheaper, so it is exclusively chosen over wrought iron. Cast iron usually refers to grey cast iron, but identifies a large group of Ferrous Alloys which solidify with a Eutectic. ^[32][33]

Wrought iron is less affected by rust than most other ferrous metals due to its slag inclusions. The slag fibers tend to disperse the corrosion into an even film, thereby resisting pitting. ^[1] Wrought iron has a rough surface so it can hold platings and coatings better. For instance, a galvanic zinc finish is approximately 25–40% thicker than the same finish on steel. ^[1]

In Table 1 the chemical composition of wrought iron is compared to that of pig iron and carbon steel. Carbon steel, also called plain carbon steel, is Steel where the main alloying constituent is Carbon. Although it appears that wrought iron and plain carbon steel have similar chemical compositions, this is deceiving. Most of the manganese, sulfur, phosphorus, and silicon are incorporated into the slag fibers present in the wrought iron, so wrought iron really is purer than plain carbon steel. ^[25]

Amongst its other properties, wrought iron becomes soft at red heat, and can be easily forged and forge welded. Forging is the term for shaping metal by using localized compressive forces Forge welding is a Welding process of heating two or more pieces of Metal and then hammering them together ^[38] It can be used to form temporary magnets, but cannot be magnetized permanently,^[39][40] and is ductile, malleable and tough. A magnet (from Greek grc μαγνήτης λίθος " Magnesian stone" is a material or object that produces a Magnetic field. Ductility is a mechanical property used to describe the extent to which materials can be deformed plastically or "stretched" into "wires" without For malleability in Cryptography, see Malleability (cryptography. Toughness, in Materials science and Metallurgy, is the resistance to Fracture of a material when stressed. ^[25]

See also

• Cast iron
• Cold iron
• Ornamental metal
• Osmond process
• Pig iron
• Wrought iron furniture

References

Notes

Bibliography

External links

• The Wrought Iron Advisory Centre - Commercial site
• Forensic Studies of the Titanic's wrought iron rivets - Jennifer Hooper McCarty and Tim Foecke