57-708: The Middlebere Plateway , or Middlebere Tramway , was a horse-drawn plateway on the Isle of Purbeck in the English county of Dorset . One of the first railways in southern England and the first in Dorset, the plateway was built by Benjamin Fayle , who was a wealthy Irish Merchant based in London and a friend of Thomas Byerley - Josiah Wedgwood's nephew. It was intended to take Purbeck Ball Clay from his pits near Corfe Castle to
114-751: A cupola , but in modern applications, it is more often melted in electric induction furnaces or electric arc furnaces. After melting is complete, the molten cast iron is poured into a holding furnace or ladle. Cast iron's properties are changed by adding various alloying elements, or alloyants . Next to carbon , silicon is the most important alloyant because it forces carbon out of solution. A low percentage of silicon allows carbon to remain in solution, forming iron carbide and producing white cast iron. A high percentage of silicon forces carbon out of solution, forming graphite and producing grey cast iron. Other alloying agents, manganese , chromium , molybdenum , titanium , and vanadium counteract silicon, and promote
171-463: A weighbridge were built near New Line Farm to the east of the road and weathering beds were also located here; these were dumps of newly dug clay which had to weather for up to a year to allow the clay to break down to make it workable. In about 1881 new pits were opened up at Norden to the south east of the New Line Farm works. New track was laid from near the workshop area to these pits, on
228-549: A wharf on Middlebere Creek in Poole Harbour , a distance of some 3.5 miles (5.6 km). Near contemporary accounts indicate that the line was built in 1805 and opened in 1806, and it is present on a map of 1811. On 16 August 1806, Fayle wrote to Wedgwood announcing the opening of the line and a reduction in the price of clay. The engineer was John Hodgkinson, who had worked with his cousin Benjamin Outram ,
285-464: A 10-tonne impeller) to be sand cast, as the chromium reduces cooling rate required to produce carbides through the greater thicknesses of material. Chromium also produces carbides with impressive abrasion resistance. These high-chromium alloys attribute their superior hardness to the presence of chromium carbides. The main form of these carbides are the eutectic or primary M 7 C 3 carbides, where "M" represents iron or chromium and can vary depending on
342-418: A carbon content of more than 2% and silicon content around 1–3%. Its usefulness derives from its relatively low melting temperature. The alloying elements determine the form in which its carbon appears: white cast iron has its carbon combined into an iron carbide named cementite , which is very hard, but brittle, as it allows cracks to pass straight through; grey cast iron has graphite flakes which deflect
399-496: A day when travelling any distance. A few remains of the Middlebere Plateway are still visible. The quay at Middlebere Creek has gradually fallen into disrepair and almost vanished. Some of the stone sleepers remain in place today, complete with holes where the rails used to be fixed, whilst others have been reused as paving stones at various locations. Others can be found in the walls at Middlebere farm. In many places
456-631: A passing crack and initiate countless new cracks as the material breaks, and ductile cast iron has spherical graphite "nodules" which stop the crack from further progressing. Carbon (C), ranging from 1.8 to 4 wt%, and silicon (Si), 1–3 wt%, are the main alloying elements of cast iron. Iron alloys with lower carbon content are known as steel . Cast iron tends to be brittle , except for malleable cast irons . With its relatively low melting point, good fluidity, castability , excellent machinability , resistance to deformation and wear resistance , cast irons have become an engineering material with
513-510: A pioneering railway and canal engineer. Papers held in Corfe Castle Town Museum state that the contractor was named Willis. At the time the manager of the clay pits was Joseph Willis and tenant at Norden Farm, so this points to a possible "self build" by Fayle's men to John Hodgkinson's instructions. Initially the railway served clay pits to the east side of the road from Wareham to Corfe Castle , but shortly thereafter it
570-483: A route planned to run alongside and to the west of the proposed Wareham to Swanage railway. When the London and South Western Railway line to Swanage was built, a 4 ft 8 + 1 ⁄ 2 in ( 1,435 mm ) standard gauge exchange siding was laid to allow clay to be transferred from the clay trucks to main-line trucks , but most of the clay continued to be hauled by horses to Middlebere Quay. At
627-563: A rule of mixtures. In any case, they offer hardness at the expense of toughness . Since carbide makes up a large fraction of the material, white cast iron could reasonably be classified as a cermet . White iron is too brittle for use in many structural components, but with good hardness and abrasion resistance and relatively low cost, it finds use in such applications as the wear surfaces ( impeller and volute ) of slurry pumps , shell liners and lifter bars in ball mills and autogenous grinding mills , balls and rings in coal pulverisers . It
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#1732773339529684-424: A spongy steel without the stress concentration effects that flakes of graphite would produce. The carbon percentage present is 3-4% and percentage of silicon is 1.8-2.8%.Tiny amounts of 0.02 to 0.1% magnesium , and only 0.02 to 0.04% cerium added to these alloys slow the growth of graphite precipitates by bonding to the edges of the graphite planes. Along with careful control of other elements and timing, this allows
741-417: A wide range of applications and are used in pipes , machines and automotive industry parts, such as cylinder heads , cylinder blocks and gearbox cases. Some alloys are resistant to damage by oxidation . In general, cast iron is notoriously difficult to weld . The earliest cast-iron artefacts date to the 5th century BC, and were discovered by archaeologists in what is now Jiangsu , China. Cast iron
798-399: A year after it was opened. The Dee bridge disaster was caused by excessive loading at the centre of the beam by a passing train, and many similar bridges had to be demolished and rebuilt, often in wrought iron . The bridge had been badly designed, being trussed with wrought iron straps, which were wrongly thought to reinforce the structure. The centres of the beams were put into bending, with
855-438: Is added in the ladle or in the furnace, on the order of 0.5–2.5%, to decrease chill, refine graphite, and increase fluidity. Molybdenum is added on the order of 0.3–1% to increase chill and refine the graphite and pearlite structure; it is often added in conjunction with nickel, copper, and chromium to form high strength irons. Titanium is added as a degasser and deoxidizer, but it also increases fluidity. Vanadium at 0.15–0.5%
912-439: Is added to cast iron to stabilize cementite, increase hardness, and increase resistance to wear and heat. Zirconium at 0.1–0.3% helps to form graphite, deoxidize, and increase fluidity. In malleable iron melts, bismuth is added at 0.002–0.01% to increase how much silicon can be added. In white iron, boron is added to aid in the production of malleable iron; it also reduces the coarsening effect of bismuth. Grey cast iron
969-420: Is characterised by its graphitic microstructure, which causes fractures of the material to have a grey appearance. It is the most commonly used cast iron and the most widely used cast material based on weight. Most cast irons have a chemical composition of 2.5–4.0% carbon, 1–3% silicon, and the remainder iron. Grey cast iron has less tensile strength and shock resistance than steel, but its compressive strength
1026-485: Is comparable to low- and medium-carbon steel. These mechanical properties are controlled by the size and shape of the graphite flakes present in the microstructure and can be characterised according to the guidelines given by the ASTM . White cast iron displays white fractured surfaces due to the presence of an iron carbide precipitate called cementite. With a lower silicon content (graphitizing agent) and faster cooling rate,
1083-453: Is difficult to cool thick castings fast enough to solidify the melt as white cast iron all the way through. However, rapid cooling can be used to solidify a shell of white cast iron, after which the remainder cools more slowly to form a core of grey cast iron. The resulting casting, called a chilled casting , has the benefits of a hard surface with a somewhat tougher interior. High-chromium white iron alloys allow massive castings (for example,
1140-605: Is known as the Iron Bridge in Shropshire , England. Cast iron was also used in the construction of buildings . Cast iron is made from pig iron , which is the product of melting iron ore in a blast furnace . Cast iron can be made directly from the molten pig iron or by re-melting pig iron, often along with substantial quantities of iron, steel, limestone, carbon (coke) and taking various steps to remove undesirable contaminants. Phosphorus and sulfur may be burnt out of
1197-637: Is now the location of the Norden station of the Swanage Railway , a heritage railway that has taken over the track of the Wareham to Swanage main line railway. The land of old clay processing works now provides a park and ride site whereby visitors can park at Norden and ride the train to Corfe Castle or Swanage. The Purbeck Mineral and Mining Museum is situated beside the station and is dedicated to Purbeck clay industry and its associated tramways on
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#17327733395291254-433: Is one of the most common alloying elements, because it refines the pearlite and graphite structures, improves toughness, and evens out hardness differences between section thicknesses. Chromium is added in small amounts to reduce free graphite, produce chill, and because it is a powerful carbide stabilizer; nickel is often added in conjunction. A small amount of tin can be added as a substitute for 0.5% chromium. Copper
1311-698: The Chirk Aqueduct and the Pontcysyllte Aqueduct , both of which remain in use following the recent restorations. The best way of using cast iron for bridge construction was by using arches , so that all the material is in compression. Cast iron, again like masonry, is very strong in compression. Wrought iron, like most other kinds of iron and indeed like most metals in general, is strong in tension, and also tough – resistant to fracturing. The relationship between wrought iron and cast iron, for structural purposes, may be thought of as analogous to
1368-527: The Congo region of the Central African forest, blacksmiths invented sophisticated furnaces capable of high temperatures over 1000 years ago. There are countless examples of welding, soldering, and cast iron created in crucibles and poured into molds. These techniques were employed for the use of composite tools and weapons with cast iron or steel blades and soft, flexible wrought iron interiors. Iron wire
1425-542: The Warring States period . This is based on an analysis of the artifact's microstructures. Because cast iron is comparatively brittle, it is not suitable for purposes where a sharp edge or flexibility is required. It is strong under compression, but not under tension. Cast iron was invented in China in the 5th century BC and poured into molds to make ploughshares and pots as well as weapons and pagodas. Although steel
1482-403: The surface tension to form the graphite into spheroidal particles rather than flakes. Due to their lower aspect ratio , the spheroids are relatively short and far from one another, and have a lower cross section vis-a-vis a propagating crack or phonon . They also have blunt boundaries, as opposed to flakes, which alleviates the stress concentration problems found in grey cast iron. In general,
1539-707: The 13th century and other travellers subsequently noted an iron industry in the Alburz Mountains to the south of the Caspian Sea . This is close to the silk route , thus the use of cast-iron technology being derived from China is conceivable. Upon its introduction to the West in the 15th century it was used for cannon and shot . Henry VIII (reigned 1509–1547) initiated the casting of cannon in England. Soon, English iron workers using blast furnaces developed
1596-533: The 1720s and 1730s by a small number of other coke -fired blast furnaces. Application of the steam engine to power blast bellows (indirectly by pumping water to a waterwheel) in Britain, beginning in 1743 and increasing in the 1750s, was a key factor in increasing the production of cast iron, which surged in the following decades. In addition to overcoming the limitation on water power, the steam-pumped-water powered blast gave higher furnace temperatures which allowed
1653-546: The Norden site. Plateway Too Many Requests If you report this error to the Wikimedia System Administrators, please include the details below. Request from 172.68.168.133 via cp1102 cp1102, Varnish XID 535715608 Upstream caches: cp1102 int Error: 429, Too Many Requests at Thu, 28 Nov 2024 05:55:39 GMT Cast iron Cast iron is a class of iron – carbon alloys with
1710-488: The alloy's composition. The eutectic carbides form as bundles of hollow hexagonal rods and grow perpendicular to the hexagonal basal plane. The hardness of these carbides are within the range of 1500-1800HV. Malleable iron starts as a white iron casting that is then heat treated for a day or two at about 950 °C (1,740 °F) and then cooled over a day or two. As a result, the carbon in iron carbide transforms into graphite and ferrite plus carbon. The slow process allows
1767-479: The annual tonnage to 22,000 long tons (22,353 t; 24,640 short tons). Horses continued to be used right up until 1946. The plateway was one of the first users of the patent axle that was designed by John Collinge of Bridge Road, Lambeth. This axle was largely used for road vehicles and a few other applications to rail vehicles. It implies that the wheels rotated on fixed axles, and, until its introduction, wheels had to be removed and axle arms greased at least once
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1824-429: The benefit of what is called precipitation hardening (as in some steels, where much smaller cementite precipitates might inhibit [plastic deformation] by impeding the movement of dislocations through the pure iron ferrite matrix). Rather, they increase the bulk hardness of the cast iron simply by virtue of their own very high hardness and their substantial volume fraction, such that the bulk hardness can be approximated by
1881-537: The blast furnaces at Coalbrookdale. Other inventions followed, including one patented by Thomas Paine . Cast-iron bridges became commonplace as the Industrial Revolution gathered pace. Thomas Telford adopted the material for his bridge upstream at Buildwas , and then for Longdon-on-Tern Aqueduct , a canal trough aqueduct at Longdon-on-Tern on the Shrewsbury Canal . It was followed by
1938-539: The bolt holes were also cast and not drilled. Thus, because of casting's draft angle, the tension from the tie bars was placed on the hole's edge rather than being spread over the length of the hole. The replacement bridge was built in wrought iron and steel. Further bridge collapses occurred, however, culminating in the Norwood Junction rail accident of 1891. Thousands of cast-iron rail underbridges were eventually replaced by steel equivalents by 1900 owing to
1995-522: The carbon in white cast iron precipitates out of the melt as the metastable phase cementite , Fe 3 C, rather than graphite. The cementite which precipitates from the melt forms as relatively large particles. As the iron carbide precipitates out, it withdraws carbon from the original melt, moving the mixture toward one that is closer to eutectic , and the remaining phase is the lower iron-carbon austenite (which on cooling might transform to martensite ). These eutectic carbides are much too large to provide
2052-439: The carbon to separate as spheroidal particles as the material solidifies. The properties are similar to malleable iron, but parts can be cast with larger sections. Cast iron and wrought iron can be produced unintentionally when smelting copper using iron ore as a flux. The earliest cast-iron artifacts date to the 5th century BC, and were discovered by archaeologists in what is now modern Luhe County , Jiangsu in China during
2109-627: The cotton, hemp , or wool being spun. As a result, textile mills had an alarming propensity to burn down. The solution was to build them completely of non-combustible materials, and it was found convenient to provide the building with an iron frame, largely of cast iron, replacing flammable wood. The first such building was at Ditherington in Shrewsbury , Shropshire. Many other warehouses were built using cast-iron columns and beams, although faulty designs, flawed beams or overloading sometimes caused building collapses and structural failures. During
2166-599: The development of steel-framed skyscrapers. Cast iron was also used sometimes for decorative facades, especially in the United States, and the Soho district of New York has numerous examples. It was also used occasionally for complete prefabricated buildings, such as the historic Iron Building in Watervliet, New York . Another important use was in textile mills . The air in the mills contained flammable fibres from
2223-520: The effects of sulfur, manganese is added, because the two form into manganese sulfide instead of iron sulfide. The manganese sulfide is lighter than the melt, so it tends to float out of the melt and into the slag . The amount of manganese required to neutralize sulfur is 1.7 × sulfur content + 0.3%. If more than this amount of manganese is added, then manganese carbide forms, which increases hardness and chilling , except in grey iron, where up to 1% of manganese increases strength and density. Nickel
2280-440: The line's 100-year life. Two horses worked in tandem pulling 5 wagons weighing almost one long ton (1.0 t; 1.1 short tons) each and with a 2-long-ton (2.03 t; 2.24-short-ton) capacity and making 3 round trips a day, giving an annual total of 9,000–10,000 long tons (9,100–10,200 t; 10,000–11,000 short tons). By 1865 and additional team of horses and wagons had been brought into use and passing places constructed to raise
2337-539: The lower edge in tension, where cast iron, like masonry , is very weak. Nevertheless, cast iron continued to be used in inappropriate structural ways, until the Tay Rail Bridge disaster of 1879 cast serious doubt on the use of the material. Crucial lugs for holding tie bars and struts in the Tay Bridge had been cast integral with the columns, and they failed in the early stages of the accident. In addition,
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2394-406: The molten iron, but this also burns out the carbon, which must be replaced. Depending on the application, carbon and silicon content are adjusted to the desired levels, which may be anywhere from 2–3.5% and 1–3%, respectively. If desired, other elements are then added to the melt before the final form is produced by casting . Cast iron is sometimes melted in a special type of blast furnace known as
2451-551: The plateway's days were numbered. The channel at Middlebere was silting up, limiting the size of vessel that could approach the quay. The company already had a deeper-water quay at Goathorn on the southern shore of Poole Harbour, used for the export of clay from pits at nearby Newton . The Middlebere Plateway was abandoned in about 1907, when it was replaced by the Norden & Goathorn Railway, which connected Fayle's clay works at Norden with their works at Newton and thence to Poole Harbour at Goathorn. N&G Railway took over much of
2508-410: The plateway's trackbed in the Norden area, including the exchange siding and the bridge over the main line railway. However the plateway's main route to Middlebere Creek, and the tunnels under the railway and road were all abandoned. As a plateway , the Middlebere Plateway differed from the edge railway that eventually became the norm, in that the flanges retaining the truck wheels on the line were on
2565-418: The properties of malleable cast iron are more like those of mild steel . There is a limit to how large a part can be cast in malleable iron, as it is made from white cast iron. Developed in 1948, nodular or ductile cast iron has its graphite in the form of very tiny nodules with the graphite in the form of concentric layers forming the nodules. As a result, the properties of ductile cast iron are that of
2622-662: The rails (plates) rather than on the wheels. The plates were three feet (0.91 m) long, L-shaped and made of cast iron , weighing 40 lb (18 kg). They were supported on stone sleepers weighing 60–70 lb (27–32 kg); the ends of the plates were held down by nails driven into wooden plugs inserted into holes in the sleepers. The gauge is generally quoted as being about 3 ft 9 in ( 1,143 mm ), although some recent archeological investigations suggest it may have been as narrow as 3 ft 6 in ( 1,067 mm ). The clay trucks were flange-less. They were hauled by horses and remained so throughout
2679-762: The relationship between wood and stone. Cast-iron beam bridges were used widely by the early railways, such as the Water Street Bridge in 1830 at the Manchester terminus of the Liverpool and Manchester Railway , but problems with its use became all too apparent when a new bridge carrying the Chester and Holyhead Railway across the River Dee in Chester collapsed killing five people in May 1847, less than
2736-475: The retention of carbon and the formation of those carbides. Nickel and copper increase strength and machinability, but do not change the amount of graphite formed. Carbon as graphite produces a softer iron, reduces shrinkage, lowers strength, and decreases density. Sulfur , largely a contaminant when present, forms iron sulfide , which prevents the formation of graphite and increases hardness . Sulfur makes molten cast iron viscous, which causes defects. To counter
2793-414: The route across Hartland moor can be traced. The tunnel under the Wareham to Corfe road is now used by a stream draining the former clay working and is a listed building , although the north portal was buried when the road was realigned in the 1980s. The iron bridge over the main line railway, first built for the plateway and then used by Fayle's Tramway , still stands. The site of the clay works at Norden
2850-403: The same time a tunnel was provided under the main line railway for use by the plateway to the original workings. In the early 1900s, the line to Norden clay works had been extended over the main line railway to serve clay pits on its western side. This line was extended across the Wareham to Corfe Castle road by a level crossing to serve further clay pits to the north east. However, by this time
2907-501: The technique of producing cast-iron cannons, which, while heavier than the prevailing bronze cannons, were much cheaper and enabled England to arm her navy better. Cast-iron pots were made at many English blast furnaces at the time. In 1707, Abraham Darby patented a new method of making pots (and kettles) thinner and hence cheaper than those made by traditional methods. This meant that his Coalbrookdale furnaces became dominant as suppliers of pots, an activity in which they were joined in
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#17327733395292964-566: The use of higher lime ratios, enabling the conversion from charcoal (supplies of wood for which were inadequate) to coke. The ironmasters of the Weald continued producing cast irons until the 1760s, and armament was one of the main uses of irons after the Restoration . The use of cast iron for structural purposes began in the late 1770s, when Abraham Darby III built The Iron Bridge , although short beams had already been used, such as in
3021-518: The widespread concern about cast iron under bridges on the rail network in Britain. Cast-iron columns , pioneered in mill buildings, enabled architects to build multi-storey buildings without the enormously thick walls required for masonry buildings of any height. They also opened up floor spaces in factories, and sight lines in churches and auditoriums. By the mid 19th century, cast iron columns were common in warehouse and industrial buildings, combined with wrought or cast iron beams, eventually leading to
3078-514: Was also produced. Numerous testimonies were made by early European missionaries of the Luba people pouring cast iron into molds to make hoes. These technological innovations were accomplished without the invention of the blast furnace which was the prerequisite for the deployment of such innovations in Europe and Asia. The technology of cast iron was transferred to the West from China. Al-Qazvini in
3135-399: Was extended under the road to serve clay workings on the other side of the road. There are two tunnels under the road, serving different workings. The northern tunnel carries a plaque on its east face reading BF 1807 . The southern tunnel has a plaque on its west face Dated in 1848 , but as the tunnel is shown on earlier tithe maps , that is believed to be a rebuilding date. Workshops and
3192-410: Was more desirable, cast iron was cheaper and thus was more commonly used for implements in ancient China, while wrought iron or steel was used for weapons. The Chinese developed a method of annealing cast iron by keeping hot castings in an oxidizing atmosphere for a week or longer in order to burn off some carbon near the surface in order to keep the surface layer from being too brittle. Deep within
3249-522: Was used in ancient China to mass-produce weaponry for warfare, as well as agriculture and architecture. During the 15th century AD, cast iron became utilized for cannons and shot in Burgundy , France, and in England during the Reformation . The amounts of cast iron used for cannons required large-scale production. The first cast-iron bridge was built during the 1770s by Abraham Darby III , and
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