Misplaced Pages

Forging

Article snapshot taken from Wikipedia with creative commons attribution-sharealike license. Give it a read and then ask your questions in the chat. We can research this topic together.

Forging is a manufacturing process involving the shaping of metal using localized compressive forces. The blows are delivered with a hammer (often a power hammer ) or a die . Forging is often classified according to the temperature at which it is performed: cold forging (a type of cold working ), warm forging, or hot forging (a type of hot working ). For the latter two, the metal is heated , usually in a forge . Forged parts can range in weight from less than a kilogram to hundreds of metric tons. Forging has been done by smiths for millennia; the traditional products were kitchenware , hardware , hand tools , edged weapons , cymbals , and jewellery .

#787212

121-533: Since the Industrial Revolution , forged parts are widely used in mechanisms and machines wherever a component requires high strength ; such forgings usually require further processing (such as machining ) to achieve a finished part. Today, forging is a major worldwide industry. Forging is one of the oldest known metalworking processes. Traditionally, forging was performed by a smith using hammer and anvil , though introducing water power to

242-460: A 20 percent higher strength-to-weight ratio compared to cast or machined parts of the same material. Forging dies are usually made of high-alloy or tool steel . Dies must be impact- and wear-resistant, maintain strength at high temperatures, and have the ability to withstand cycles of rapid heating and cooling. In order to produce a better, more economical die the following standards are maintained: Barrelling occurs when, due to friction between

363-400: A better way could be found to remove the seed. Eli Whitney responded to the challenge by inventing the inexpensive cotton gin . A man using a cotton gin could remove seed from as much upland cotton in one day as would previously have taken two months to process, working at the rate of one pound of cotton per day. These advances were capitalised on by entrepreneurs , of whom the best known

484-520: A cottage industry under the putting-out system . Occasionally, the work was done in the workshop of a master weaver. Under the putting-out system, home-based workers produced under contract to merchant sellers, who often supplied the raw materials. In the off-season, the women, typically farmers' wives, did the spinning and the men did the weaving. Using the spinning wheel , it took anywhere from four to eight spinners to supply one handloom weaver. The flying shuttle , patented in 1733 by John Kay —with

605-419: A distinctly different flow pattern. Both of these machines can be used for open-die or closed-die forging. A forging press , often just called a press, is used for press forging. There are two main types: mechanical and hydraulic presses. Mechanical presses function by using cams, cranks and/or toggles to produce a preset (a predetermined force at a certain location in the stroke) and reproducible stroke. Due to

726-478: A forging preform from liquid metal. The casting is removed after it has solidified, but while still hot. It is then finished in a single cavity die. The flash is trimmed, then the part is quench hardened. Another variation follows the same process as outlined above, except the preform is produced by the spraying deposition of metal droplets into shaped collectors (similar to the Osprey process ). Closed-die forging has

847-670: A groundswell of enterprise and productivity transformed the economy in the 17th century, laying the foundations for the world's first industrial economy. Britain was already a nation of makers by the year 1700" and "the history of Britain needs to be rewritten". Eric Hobsbawm held that the Industrial Revolution began in Britain in the 1780s and was not fully felt until the 1830s or 1840s, while T. S. Ashton held that it occurred roughly between 1760 and 1830. Rapid adoption of mechanized textiles spinning occurred in Britain in

968-430: A high initial cost due to the creation of dies and required design work to make working die cavities. However, it has low recurring costs for each part, thus forgings become more economical with greater production volume. This is one of the major reasons closed-die forgings are often used in the automotive and tool industries. Another reason forgings are common in these industrial sectors is that forgings generally have about

1089-457: A higher degree of mechanical and orientation integrity. By the constraint of oxidation to the outer layers of the part, reduced levels of microcracking occur in the finished part. Press forging can be used to perform all types of forging, including open-die and impression-die forging. Impression-die press forging usually requires less draft than drop forging and has better dimensional accuracy. Also, press forgings can often be done in one closing of

1210-425: A major turning point in history, comparable only to humanity's adoption of agriculture with respect to material advancement. The Industrial Revolution influenced in some way almost every aspect of daily life. In particular, average income and population began to exhibit unprecedented sustained growth. Some economists have said the most important effect of the Industrial Revolution was that the standard of living for

1331-511: A mechanical press are its flexibility and greater capacity. The disadvantages include a slower, larger, and costlier machine to operate. The roll forging, upsetting, and automatic hot forging processes all use specialized machinery. Industrial Revolution The Industrial Revolution , sometimes divided into the First Industrial Revolution and Second Industrial Revolution , was a period of global transition of

SECTION 10

#1732787422788

1452-421: A mechanised industry. Other inventors increased the efficiency of the individual steps of spinning (carding, twisting and spinning, and rolling) so that the supply of yarn increased greatly. Steam power was then applied to drive textile machinery. Manchester acquired the nickname Cottonopolis during the early 19th century owing to its sprawl of textile factories. Although mechanisation dramatically decreased

1573-726: A more even thickness. The technology was developed with the help of John Wyatt of Birmingham . Paul and Wyatt opened a mill in Birmingham which used their rolling machine powered by a donkey. In 1743, a factory opened in Northampton with 50 spindles on each of five of Paul and Wyatt's machines. This operated until about 1764. A similar mill was built by Daniel Bourn in Leominster , but this burnt down. Both Lewis Paul and Daniel Bourn patented carding machines in 1748. Based on two sets of rollers that travelled at different speeds, it

1694-609: A new group of innovations in what has been called the Second Industrial Revolution . These included new steel-making processes , mass production , assembly lines , electrical grid systems, the large-scale manufacture of machine tools, and the use of increasingly advanced machinery in steam-powered factories. The earliest recorded use of the term "Industrial Revolution" was in July 1799 by French envoy Louis-Guillaume Otto , announcing that France had entered

1815-406: A number of subsequent improvements including an important one in 1747—doubled the output of a weaver, worsening the imbalance between spinning and weaving. It became widely used around Lancashire after 1760 when John's son, Robert , invented the dropbox, which facilitated changing thread colors. Lewis Paul patented the roller spinning frame and the flyer-and- bobbin system for drawing wool to

1936-436: A particular process window. To provide good forming conditions a homogeneous temperature distribution in the entire workpiece is necessary. Therefore, the control of the tool temperature has a major influence to the process. For example, by optimizing the preform geometries the local effective strains can be influenced to reduce local overheating for a more homogeneous temperature distribution. High-strength aluminium alloys have

2057-410: A reverberatory furnace, coal or coke could be used as fuel. The puddling process continued to be used until the late 19th century when iron was being displaced by mild steel. Because puddling required human skill in sensing the iron globs, it was never successfully mechanised. Rolling was an important part of the puddling process because the grooved rollers expelled most of the molten slag and consolidated

2178-438: A simple, wooden framed machine that only cost about £6 for a 40-spindle model in 1792 and was used mainly by home spinners. The jenny produced a lightly twisted yarn only suitable for weft, not warp. The spinning frame or water frame was developed by Richard Arkwright who, along with two partners, patented it in 1769. The design was partly based on a spinning machine built by Kay, who was hired by Arkwright. For each spindle

2299-487: A tool to form holes or be a cut-off tool. Open-die forgings can be worked into shapes which include discs, hubs, blocks, shafts (including step shafts or with flanges), sleeves, cylinders, flats, hexes, rounds, plate, and some custom shapes. Open-die forging lends itself to short runs and is appropriate for art smithing and custom work. In some cases, open-die forging may be employed to rough-shape ingots to prepare them for subsequent operations. Open-die forging may also orient

2420-625: A variety of cotton cloth, some of exceptionally fine quality. Cotton was a difficult raw material for Europe to obtain before it was grown on colonial plantations in the Americas. The early Spanish explorers found Native Americans growing unknown species of excellent quality cotton: sea island cotton ( Gossypium barbadense ) and upland green seeded cotton Gossypium hirsutum . Sea island cotton grew in tropical areas and on barrier islands of Georgia and South Carolina but did poorly inland. Sea island cotton began being exported from Barbados in

2541-493: A weight. The weights kept the twist from backing up before the rollers. The bottom rollers were wood and metal, with fluting along the length. The water frame was able to produce a hard, medium-count thread suitable for warp, finally allowing 100% cotton cloth to be made in Britain. Arkwright and his partners used water power at a factory in Cromford , Derbyshire in 1771, giving the invention its name. Samuel Crompton invented

SECTION 20

#1732787422788

2662-430: Is Arkwright. He is credited with a list of inventions, but these were actually developed by such people as Kay and Thomas Highs ; Arkwright nurtured the inventors, patented the ideas, financed the initiatives, and protected the machines. He created the cotton mill which brought the production processes together in a factory, and he developed the use of power—first horsepower and then water power—which made cotton manufacture

2783-436: Is also used as a thermal barrier to restrict heat transfer from the workpiece to the die. Finally, the lubricant acts as a parting compound to prevent the part from sticking in the dies. Press forging works by slowly applying a continuous pressure or force, which differs from the near-instantaneous impact of drop-hammer forging. The amount of time the dies are in contact with the workpiece is measured in seconds (as compared to

2904-424: Is attached to an anvil. Usually, the hammer die is shaped as well. The hammer is then dropped on the workpiece, causing the metal to flow and fill the die cavities. The hammer is generally in contact with the workpiece on the scale of milliseconds. Depending on the size and complexity of the part, the hammer may be dropped multiple times in quick succession. Excess metal is squeezed out of the die cavities, forming what

3025-399: Is called "edging" because it is usually carried out on the ends of the workpiece. " Fullering " is a similar process that thins out sections of the forging using a convex shaped die. These processes prepare the workpieces for further forging processes. Impression-die forging is also called "closed-die forging". In impression-die forging, the metal is placed in a die resembling a mold, which

3146-572: Is called "flashless forging", or "true closed-die forging". In this type of forging, the die cavities are completely closed, which keeps the workpiece from forming flash. The major advantage to this process is that less metal is lost to flash. Flash can account for 20 to 45% of the starting material. The disadvantages of this process include additional cost due to a more complex die design and the need for better lubrication and workpiece placement. There are other variations of part formation that integrate impression-die forging. One method incorporates casting

3267-411: Is deemed cold forging . The main advantage of hot forging is that it can be done more quickly and precisely, and as the metal is deformed work hardening effects are negated by the recrystallization process. Cold forging typically results in work hardening of the piece. Drop forging is a forging process where a hammer is raised and then "dropped" into the workpiece to deform it according to the shape of

3388-402: Is done either with presses or with hammers powered by compressed air, electricity, hydraulics or steam. These hammers may have reciprocating weights in the thousands of pounds. Smaller power hammers , 500 lb (230 kg) or less reciprocating weight, and hydraulic presses are common in art smithies as well. Some steam hammers remain in use, but they became obsolete with the availability of

3509-488: Is forged in a "final" or "finisher" impression cavity. If there is only a short run of parts to be done, then it may be more economical for the die to lack a final impression cavity and instead machine the final features. Impression-die forging has been improved in recent years through increased automation which includes induction heating, mechanical feeding, positioning and manipulation, and the direct heat treatment of parts after forging. One variation of impression-die forging

3630-455: Is forming of a work piece in a single step in several directions. The multidirectional forming takes place through constructive measures of the tool. The vertical movement of the press ram is redirected using wedges which distributes and redirects the force of the forging press in horizontal directions. Isothermal forging is a process by which the materials and the die are heated to the same temperature ( iso- meaning "equal"). Adiabatic heating

3751-466: Is mainly used for aerospace applications. Magnesium alloys are more difficult to forge due to their low plasticity, low sensitivity to strain rates and narrow forming temperature. Using semi-open die hot forging with a three-slide forging press (TSFP) has become a newly developed forging method for Mg-Al alloy AZ31, commonly used in forming aircraft brackets. This forging method has shown to improve tensile properties but lacks uniform grain size. Even though

Forging - Misplaced Pages Continue

3872-430: Is more economical than hammer forging. The operation also creates closer tolerances. In hammer forging a lot of the work is absorbed by the machinery; when in press forging, the greater percentage of work is used in the work piece. Another advantage is that the operation can be used to create any size part because there is no limit to the size of the press forging machine. New press forging techniques have been able to create

3993-448: Is most common when parts are forged without heating the slug, bar or billet. Aluminum is a common material that can be cold forged depending on final shape. Lubrication of the parts being formed is critical to increase the life of the mating dies. Unlike the above processes, induction forging is based on the type of heating style used. Many of the above processes can be used in conjunction with this heating method. Multidirectional forging

4114-446: Is nearly double that of conventional forging because contact times are on the order of 0.06-second. The downside is that this process is only feasible on smaller symmetric parts and cost; the initial investment can be over $ 10 million, so large quantities are required to justify this process. The process starts by heating the bar to 1,200 to 1,300 °C (2,190 to 2,370 °F) in less than 60 seconds using high-power induction coils. It

4235-415: Is reduced in thickness and increased in length. Roll forging is performed using two cylindrical or semi-cylindrical rolls, each containing one or more shaped grooves. A heated bar is inserted into the rolls and when it hits a spot the rolls rotate and the bar is progressively shaped as it is rolled through the machine. The piece is then transferred to the next set of grooves or turned around and reinserted into

4356-420: Is referred to as " flash ". The flash cools more rapidly than the rest of the material; this cool metal is stronger than the metal in the die, so it helps prevent more flash from forming. This also forces the metal to completely fill the die cavity. After forging, the flash is removed. In commercial impression-die forging, the workpiece is usually moved through a series of cavities in a die to get from an ingot to

4477-454: Is required to operate the machinery. There is no flash produced so material savings are between 20 and 30% over conventional forging. The final product is a consistent 1,050 °C (1,920 °F) so air cooling will result in a part that is still easily machinable (the advantage being the lack of annealing required after forging). Tolerances are usually ±0.3 mm (0.012 in), surfaces are clean, and draft angles are 0.5 to 1°. Tool life

4598-403: Is then descaled with rollers, sheared into blanks, and transferred through several successive forming stages, during which it is upset, preformed, final forged, and pierced (if necessary). This process can also be coupled with high-speed cold-forming operations. Generally, the cold forming operation will do the finishing stage so that the advantages of cold-working can be obtained, while maintaining

4719-407: Is used to assist in the deformation of the material, meaning the strain rates are highly controlled. This technique is commonly used for forging aluminium, which has a lower forging temperature than steels. Forging temperatures for aluminum are around 430 °C (806 °F), while steels and super alloys can be 930 to 1,260 °C (1,710 to 2,300 °F). Benefits: Disadvantages: Depending on

4840-399: Is very typical for molders to have their operators trim flash with hand tools at the molding machine between cycles. Many molders and OEMs seek out the use of batch processes including vibratory tumbling, cryogenic deflashing or media blasting to remove unwanted flash from large batches of parts. In plastic injection, a faint mark called a witness mark (or witness line ) will occur along

4961-593: The British Agricultural Revolution , to provide excess manpower and food; a pool of managerial and entrepreneurial skills; available ports, rivers, canals, and roads to cheaply move raw materials and outputs; natural resources such as coal, iron, and waterfalls; political stability and a legal system that supported business; and financial capital available to invest. Once industrialisation began in Great Britain, new factors can be added:

Forging - Misplaced Pages Continue

5082-639: The East India Company . The development of trade and the rise of business were among the major causes of the Industrial Revolution. Developments in law also facilitated the revolution, such as courts ruling in favour of property rights . An entrepreneurial spirit and consumer revolution helped drive industrialisation in Britain, which after 1800, was emulated in Belgium, the United States, and France. The Industrial Revolution marked

5203-488: The spinning mule in 1779, so called because it is a hybrid of Arkwright's water frame and James Hargreaves 's spinning jenny in the same way that a mule is the product of crossbreeding a female horse with a male donkey . Crompton's mule was able to produce finer thread than hand spinning and at a lower cost. Mule-spun thread was of suitable strength to be used as a warp and finally allowed Britain to produce highly competitive yarn in large quantities. Realising that

5324-582: The technological and architectural innovations were of British origin. By the mid-18th century, Britain was the world's leading commercial nation, controlling a global trading empire with colonies in North America and the Caribbean. Britain had major military and political hegemony on the Indian subcontinent ; particularly with the proto-industrialised Mughal Bengal , through the activities of

5445-441: The 1650s. Upland green seeded cotton grew well on inland areas of the southern U.S. but was not economical because of the difficulty of removing seed, a problem solved by the cotton gin . A strain of cotton seed brought from Mexico to Natchez, Mississippi , in 1806 became the parent genetic material for over 90% of world cotton production today; it produced bolls that were three to four times faster to pick. The Age of Discovery

5566-453: The 1780s, and high rates of growth in steam power and iron production occurred after 1800. Mechanised textile production spread from Great Britain to continental Europe and the United States in the early 19th century, with important centres of textiles, iron and coal emerging in Belgium and the United States and later textiles in France. An economic recession occurred from the late 1830s to

5687-496: The Indian industry. Bar iron was the commodity form of iron used as the raw material for making hardware goods such as nails, wire, hinges, horseshoes, wagon tires, chains, etc., as well as structural shapes. A small amount of bar iron was converted into steel. Cast iron was used for pots, stoves, and other items where its brittleness was tolerable. Most cast iron was refined and converted to bar iron, with substantial losses. Bar iron

5808-480: The Industrial Revolution, thus causing the Great Divergence . Some historians, such as John Clapham and Nicholas Crafts , have argued that the economic and social changes occurred gradually and that the term revolution is a misnomer. This is still a subject of debate among some historians. Six factors facilitated industrialisation: high levels of agricultural productivity, such as that reflected in

5929-577: The Scottish inventor James Beaumont Neilson in 1828, was the most important development of the 19th century for saving energy in making pig iron. By using preheated combustion air, the amount of fuel to make a unit of pig iron was reduced at first by between one-third using coke or two-thirds using coal; the efficiency gains continued as the technology improved. Hot blast also raised the operating temperature of furnaces, increasing their capacity. Using less coal or coke meant introducing fewer impurities into

6050-556: The Western European models in the late 19th century. The commencement of the Industrial Revolution is closely linked to a small number of innovations, beginning in the second half of the 18th century. By the 1830s, the following gains had been made in important technologies: In 1750, Britain imported 2.5 million pounds of raw cotton, most of which was spun and woven by the cottage industry in Lancashire . The work

6171-488: The application of magnesium alloys increases by 15–20% each year in the aerospace and automotive industry, forging magnesium alloys with specialized dies is expensive and an unfeasible method to produce parts for a mass market. Instead, most magnesium alloy parts for industry are produced by casting methods. The most common type of forging equipment is the hammer and anvil. Principles behind the hammer and anvil are still used today in drop-hammer equipment. The principle behind

SECTION 50

#1732787422788

6292-471: The coal do not migrate into the metal. This technology was applied to lead from 1678 and to copper from 1687. It was also applied to iron foundry work in the 1690s, but in this case the reverberatory furnace was known as an air furnace. (The foundry cupola is a different, and later, innovation.) Coke pig iron was hardly used to produce wrought iron until 1755–56, when Darby's son Abraham Darby II built furnaces at Horsehay and Ketley where low sulfur coal

6413-409: The coke pig iron he made was not suitable for making wrought iron and was used mostly for the production of cast iron goods, such as pots and kettles. He had the advantage over his rivals in that his pots, cast by his patented process, were thinner and cheaper than theirs. In 1750, coke had generally replaced charcoal in the smelting of copper and lead and was in widespread use in glass production. In

6534-467: The column of materials (iron ore, fuel, slag) flowing down the blast furnace more porous and did not crush in the much taller furnaces of the late 19th century. As cast iron became cheaper and widely available, it began being a structural material for bridges and buildings. A famous early example is the Iron Bridge built in 1778 with cast iron produced by Abraham Darby III. However, most cast iron

6655-536: The complexity of the part requires so many mating pieces with such precise geometries that it is almost impossible to create a perfect fit on every impression. Most often, the type of material being molded, and its attendant viscosity in its liquid form, is the primary factor that leads to the creation of the unwanted mold flash. The process of removing flash, known as deflashing , is commonly performed via cutting, breaking, grinding , or tumbling . Some foundries use robot autogrinders to remove this unwanted material. It

6776-495: The cost of cotton cloth, by the mid-19th century machine-woven cloth still could not equal the quality of hand-woven Indian cloth, in part because of the fineness of thread made possible by the type of cotton used in India, which allowed high thread counts. However, the high productivity of British textile manufacturing allowed coarser grades of British cloth to undersell hand-spun and woven fabric in low-wage India, eventually destroying

6897-542: The cotton textile industry in Britain was 2.6% in 1760, 17% in 1801, and 22.4% in 1831. Value added by the British woollen industry was 14.1% in 1801. Cotton factories in Britain numbered approximately 900 in 1797. In 1760, approximately one-third of cotton cloth manufactured in Britain was exported, rising to two-thirds by 1800. In 1781, cotton spun amounted to 5.1 million pounds, which increased to 56 million pounds by 1800. In 1800, less than 0.1% of world cotton cloth

7018-427: The country. Steam engines made the use of higher-pressure and volume blast practical; however, the leather used in bellows was expensive to replace. In 1757, ironmaster John Wilkinson patented a hydraulic powered blowing engine for blast furnaces. The blowing cylinder for blast furnaces was introduced in 1760 and the first blowing cylinder made of cast iron is believed to be the one used at Carrington in 1768 that

7139-448: The die. There are two types of drop forging: open-die drop forging and impression-die (or closed-die) drop forging. As the names imply, the difference is in the shape of the die, with the former not fully enclosing the workpiece, while the latter does. Open-die forging is also known as smith forging . In open-die forging, a hammer strikes and deforms the workpiece, which is placed on a stationary anvil . Open-die forging gets its name from

7260-477: The dies are in contact with workpiece; the dies facilitate drastically more heat transfer than the surrounding atmosphere. As the workpiece cools it becomes stronger and less ductile, which may induce cracking if deformation continues. Therefore, heated dies are usually used to reduce heat loss, promote surface flow, and enable the production of finer details and closer tolerances. The workpiece may also need to be reheated. When done in high productivity, press forging

7381-472: The dies, allowing for easy automation. Upset forging increases the diameter of the workpiece by compressing its length. Based on number of pieces produced, this is the most widely used forging process. A few examples of common parts produced using the upset forging process are engine valves, couplings, bolts, screws, and other fasteners. Upset forging is usually done in special high-speed machines called crank presses . The machines are usually set up to work in

SECTION 60

#1732787422788

7502-456: The eagerness of British entrepreneurs to export industrial expertise and the willingness to import the process. Britain met the criteria and industrialized starting in the 18th century, and then it exported the process to western Europe (especially Belgium, France, and the German states) in the early 19th century. The United States copied the British model in the early 19th century, and Japan copied

7623-607: The early 1840s when the adoption of the Industrial Revolution's early innovations, such as mechanised spinning and weaving, slowed as their markets matured; and despite the increasing adoption of locomotives, steamboats and steamships, and hot blast iron smelting . New technologies such as the electrical telegraph , widely introduced in the 1840s and 1850s in the United Kingdom and the United States, were not powerful enough to drive high rates of economic growth. Rapid economic growth began to reoccur after 1870, springing from

7744-465: The expiration of the Arkwright patent would greatly increase the supply of spun cotton and lead to a shortage of weavers, Edmund Cartwright developed a vertical power loom which he patented in 1785. In 1776, he patented a two-man operated loom. Cartwright's loom design had several flaws, the most serious being thread breakage. Samuel Horrocks patented a fairly successful loom in 1813. Horock's loom

7865-429: The fact that the dies (the surfaces that are in contact with the workpiece) do not enclose the workpiece, allowing it to flow except where contacted by the dies. The operator therefore needs to orient and position the workpiece to get the desired shape. The dies are usually flat in shape, but some have a specially shaped surface for specialized operations. For example, a die may have a round, concave, or convex surface or be

7986-456: The final form. The first impression is used to distribute the metal into the rough shape in accordance to the needs of later cavities; this impression is called an "edging", "fullering", or "bending" impression. The following cavities are called "blocking" cavities, in which the piece is working into a shape that more closely resembles the final product. These stages usually impart the workpiece with generous bends and large fillets . The final shape

8107-444: The final product from a precision forging needs little or no final machining. Cost savings are gained from the use of less material, and thus less scrap, the overall decrease in energy used, and the reduction or elimination of machining. Precision forging also requires less of a draft, 1° to 0°. The downside of this process is its cost, therefore it is only implemented if significant cost reduction can be achieved. Near net shape forging

8228-528: The first highly mechanised factory was John Lombe 's water-powered silk mill at Derby , operational by 1721. Lombe learned silk thread manufacturing by taking a job in Italy and acting as an industrial spy; however, because the Italian silk industry guarded its secrets closely, the state of the industry at that time is unknown. Although Lombe's factory was technically successful, the supply of raw silk from Italy

8349-400: The first successful cylinder for a Boulton and Watt steam engine in 1776, he was given an exclusive contract for providing cylinders. After Watt developed a rotary steam engine in 1782, they were widely applied to blowing, hammering, rolling and slitting. The solutions to the sulfur problem were the addition of sufficient limestone to the furnace to force sulfur into the slag as well as

8470-401: The forming temperature steel forging can be divided into: For industrial processes steel alloys are primarily forged in hot condition. Brass, bronze, copper, precious metals and their alloys are manufactured by cold forging processes; each metal requires a different forging temperature. Due to the narrow temperature range and high thermal conductivity, aluminium forging can only be realized in

8591-455: The foundation. Moreover, a large machine base is needed to absorb the impacts. To overcome some shortcomings of the drop-hammer, the counterblow machine or impactor is used. In a counterblow machine both the hammer and anvil move and the workpiece is held between them. Here excess energy becomes recoil. This allows the machine to work horizontally and have a smaller base. Other advantages include less noise, heat and vibration. It also produces

8712-534: The general population in the Western world began to increase consistently for the first time in history, although others have said that it did not begin to improve meaningfully until the late 19th and 20th centuries. GDP per capita was broadly stable before the Industrial Revolution and the emergence of the modern capitalist economy, while the Industrial Revolution began an era of per-capita economic growth in capitalist economies. Economic historians agree that

8833-417: The grain to increase strength in the required direction. " Cogging " is the successive deformation of a bar along its length using an open-die drop forge. It is commonly used to work a piece of raw material to the proper thickness. Once the proper thickness is achieved the proper width is achieved via "edging". " Edging " is the process of concentrating material using a concave shaped open-die. The process

8954-412: The high speed of automatic hot forging. Examples of parts made by this process are: wheel hub unit bearings, transmission gears, tapered roller bearing races, stainless steel coupling flanges, and neck rings for liquid propane (LP) gas cylinders. Manual transmission gears are an example of automatic hot forging used in conjunction with cold working. Roll forging is a process where round or flat bar stock

9075-446: The horizontal plane, to facilitate the quick exchange of workpieces from one station to the next, but upsetting can also be done in a vertical crank press or a hydraulic press. The initial workpiece is usually wire or rod, but some machines can accept bars up to 25 cm (9.8 in) in diameter and a capacity of over 1000 tons. The standard upsetting machine employs split dies that contain multiple cavities. The dies open enough to allow

9196-623: The human economy towards more widespread, efficient and stable manufacturing processes that succeeded the Agricultural Revolution . Beginning in Great Britain , the Industrial Revolution spread to continental Europe and the United States , from around 1760 to about 1820–1840. This transition included going from hand production methods to machines ; new chemical manufacturing and iron production processes;

9317-433: The impression-die forging method are outlined in the table below. The dimensions across the parting plane are affected by the closure of the dies, and are therefore dependent on die wear and the thickness of the final flash. Dimensions that are completely contained within a single die segment or half can be maintained at a significantly greater level of accuracy. A lubricant is used when forging to reduce friction and wear. It

9438-451: The increasing use of water power and steam power ; the development of machine tools ; and the rise of the mechanised factory system . Output greatly increased, and the result was an unprecedented rise in population and the rate of population growth . The textile industry was the first to use modern production methods, and textiles became the dominant industry in terms of employment, value of output, and capital invested. Many of

9559-517: The iron industries during the Industrial Revolution was the replacement of wood and other bio-fuels with coal ; for a given amount of heat, mining coal required much less labour than cutting wood and converting it to charcoal , and coal was much more abundant than wood, supplies of which were becoming scarce before the enormous increase in iron production that took place in the late 18th century. In 1709, Abraham Darby made progress using coke to fuel his blast furnaces at Coalbrookdale . However,

9680-496: The late 19th century, and his expression did not enter everyday language until then. Credit for popularising the term may be given to Arnold Toynbee , whose 1881 lectures gave a detailed account of the term. Economic historians and authors such as Mendels, Pomeranz , and Kridte argue that proto-industrialisation in parts of Europe, the Muslim world , Mughal India , and China created the social and economic conditions that led to

9801-465: The machine at room temperature and hot forged products emerge from the other end. This all occurs rapidly; small parts can be made at a rate of 180 parts per minute (ppm) and larger can be made at a rate of 90 ppm. The parts can be solid or hollow, round or symmetrical, up to 6 kg (13 lb), and up to 18 cm (7.1 in) in diameter. The main advantages to this process are its high output rate and ability to accept low-cost materials. Little labor

9922-444: The machine is simple: raise the hammer and drop it or propel it into the workpiece, which rests on the anvil. The main variations between drop-hammers are in the way the hammer is powered; the most common being air and steam hammers. Drop-hammers usually operate in a vertical position. The main reason for this is excess energy (energy that is not used to deform the workpiece) that is not released as heat or sound needs to be transmitted to

10043-467: The mass of hot wrought iron. Rolling was 15 times faster at this than a trip hammer . A different use of rolling, which was done at lower temperatures than that for expelling slag, was in the production of iron sheets, and later structural shapes such as beams, angles, and rails. The puddling process was improved in 1818 by Baldwyn Rogers, who replaced some of the sand lining on the reverberatory furnace bottom with iron oxide . In 1838 John Hall patented

10164-427: The material between the two surfaces of a mold (beginning along the parting line ) or between the base material and the mold in the case of overmolding . Molding flash is seen when the optimized parameter on cull height is not calibrated. Proper design of mold parting surfaces can reduce or eliminate flash. Molding flash can be caused from old or worn mold cavities that no longer fit tightly together. Other times,

10285-436: The metal temperature is above or below the recrystallization temperature. If the temperature is above the material's recrystallization temperature it is deemed hot forging ; if the temperature is below the material's recrystallization temperature but above 30% of the recrystallization temperature (on an absolute scale) it is deemed warm forging ; if below 30% of the recrystallization temperature (usually room temperature) then it

10406-418: The milliseconds of drop-hammer forges). The press forging operation can be done either cold or hot. The main advantage of press forging, as compared to drop-hammer forging, is its ability to deform the complete workpiece. Drop-hammer forging usually only deforms the surfaces of the work piece in contact with the hammer and anvil; the interior of the workpiece will stay relatively undeformed. Another advantage to

10527-407: The nature of this type of system, different forces are available at different stroke positions. Mechanical presses are faster than their hydraulic counterparts (up to 50 strokes per minute). Their capacities range from 3 to 160 MN (300 to 18,000 short tons-force). Hydraulic presses, such as the four-die device , use fluid pressure and a piston to generate force. The advantages of a hydraulic press over

10648-599: The number of cotton goods consumed in Western Europe was minor until the early 19th century. By 1600, Flemish refugees began weaving cotton cloth in English towns where cottage spinning and weaving of wool and linen was well established. They were left alone by the guilds who did not consider cotton a threat. Earlier European attempts at cotton spinning and weaving were in 12th-century Italy and 15th-century southern Germany, but these industries eventually ended when

10769-418: The onset of the Industrial Revolution is the most important event in human history since the domestication of animals and plants. The precise start and end of the Industrial Revolution is still debated among historians, as is the pace of economic and social changes . According to Cambridge historian Leigh Shaw-Taylor, Britain was already industrialising in the 17th century, and "Our database shows that

10890-495: The other, more convenient, power sources. There are many different kinds of forging processes available; however, they can be grouped into three main classes: Common forging processes include: roll forging, swaging , cogging , open-die forging, impression-die forging (closed die forging), press forging, cold forging, automatic hot forging and upsetting. All of the following forging processes can be performed at various temperatures; however, they are generally classified by whether

11011-419: The pig iron. This meant that lower quality coal could be used in areas where coking coal was unavailable or too expensive; however, by the end of the 19th century transportation costs fell considerably. Flash (manufacturing) Flash , also known as flashing , is excess material attached to a molded , forged , or cast product, which must usually be removed. This is typically caused by leakage of

11132-442: The process includes the knowledge of the new part's strain rate. By controlling the compression rate of the press forging operation, the internal strain can be controlled. There are a few disadvantages to this process, most stemming from the workpiece being in contact with the dies for such an extended period of time. The operation is a time-consuming process due to the amount and length of steps. The workpiece will cool faster because

11253-422: The production and working of iron in the 12th century allowed the use of large trip hammers or power hammers that increased the amount and size of iron that could be produced and forged. The smithy or forge has evolved over centuries to become a facility with engineered processes, production equipment, tooling, raw materials and products to meet the demands of modern industry. In modern times, industrial forging

11374-501: The race to industrialise. In his 1976 book Keywords: A Vocabulary of Culture and Society , Raymond Williams states in the entry for "Industry": "The idea of a new social order based on major industrial change was clear in Southey and Owen , between 1811 and 1818, and was implicit as early as Blake in the early 1790s and Wordsworth at the turn of the [19th] century." The term Industrial Revolution applied to technological change

11495-443: The same grooves. This continues until the desired shape and size is achieved. The advantage of this process is there is no flash and it imparts a favorable grain structure into the workpiece. Examples of products produced using this method include axles , tapered levers and leaf springs . This process is also known as precision forging . It was developed to minimize cost and waste associated with post-forging operations. Therefore,

11616-418: The slag from almost 50% to around 8%. Puddling became widely used after 1800. Up to that time, British iron manufacturers had used considerable amounts of iron imported from Sweden and Russia to supplement domestic supplies. Because of the increased British production, imports began to decline in 1785, and by the 1790s Britain eliminated imports and became a net exporter of bar iron. Hot blast , patented by

11737-457: The smelting and refining of iron, coal and coke produced inferior iron to that made with charcoal because of the coal's sulfur content. Low sulfur coals were known, but they still contained harmful amounts. Conversion of coal to coke only slightly reduces the sulfur content. A minority of coals are coking. Another factor limiting the iron industry before the Industrial Revolution was the scarcity of water power to power blast bellows. This limitation

11858-528: The supply of cotton was cut off. The Moors in Spain grew, spun, and wove cotton beginning around the 10th century. British cloth could not compete with Indian cloth because India's labour cost was approximately one-fifth to one-sixth that of Britain's. In 1700 and 1721, the British government passed Calico Acts to protect the domestic woollen and linen industries from the increasing amounts of cotton fabric imported from India. The demand for heavier fabric

11979-615: The tensile strength of medium strong steel alloys while providing significant weight advantages. Therefore, aluminium forged parts are mainly used in aerospace, automotive industry and many other fields of engineering especially in those fields, where highest safety standards against failure by abuse, by shock or vibratory stresses are needed. Such parts are for example pistons, chassis parts, steering components and brake parts. Commonly used alloys are AlSi1MgMn ( EN AW-6082 ) and AlZnMgCu1,5 ( EN AW-7075 ). About 80% of all aluminium forged parts are made of AlSi1MgMn. The high-strength alloy AlZnMgCu1,5

12100-415: The use of low sulfur coal. The use of lime or limestone required higher furnace temperatures to form a free-flowing slag. The increased furnace temperature made possible by improved blowing also increased the capacity of blast furnaces and allowed for increased furnace height. In addition to lower cost and greater availability, coke had other important advantages over charcoal in that it was harder and made

12221-406: The use of roasted tap cinder ( iron silicate ) for the furnace bottom, greatly reducing the loss of iron through increased slag caused by a sand lined bottom. The tap cinder also tied up some phosphorus, but this was not understood at the time. Hall's process also used iron scale or rust which reacted with carbon in the molten iron. Hall's process, called wet puddling , reduced losses of iron with

12342-410: The water frame used a series of four pairs of rollers, each operating at a successively higher rotating speed, to draw out the fibre which was then twisted by the spindle. The roller spacing was slightly longer than the fibre length. Too close a spacing caused the fibres to break while too distant a spacing caused uneven thread. The top rollers were leather-covered and loading on the rollers was applied by

12463-415: The work piece and the die or punch , the work piece bulges at its centre in such a way as to resemble a barrel . This leads to the central part of the work piece to come in contact with the sides of the die sooner than if there were no friction present, creating a much greater increase in the pressure required for the punch to finish the forging. The dimensional tolerances of a steel part produced using

12584-543: The workpiece to move from one cavity to the next; the dies then close and the heading tool, or ram, then moves longitudinally against the bar, upsetting it into the cavity. If all of the cavities are utilized on every cycle, then a finished part will be produced with every cycle, which makes this process advantageous for mass production. These rules must be followed when designing parts to be upset forged: The automatic hot forging process involves feeding mill-length steel bars (typically 7 m (23 ft) long) into one end of

12705-505: Was 7,800 tons and coke cast iron was 250,000 tons. In 1750, the UK imported 31,200 tons of bar iron and either refined from cast iron or directly produced 18,800 tons of bar iron using charcoal and 100 tons using coke. In 1796, the UK was making 125,000 tons of bar iron with coke and 6,400 tons with charcoal; imports were 38,000 tons and exports were 24,600 tons. In 1806 the UK did not import bar iron but exported 31,500 tons. A major change in

12826-407: Was a means of decarburizing molten pig iron by slow oxidation in a reverberatory furnace by manually stirring it with a long rod. The decarburized iron, having a higher melting point than cast iron, was raked into globs by the puddler. When the glob was large enough, the puddler would remove it. Puddling was backbreaking and extremely hot work. Few puddlers lived to be 40. Because puddling was done in

12947-606: Was available (and not far from Coalbrookdale). These furnaces were equipped with water-powered bellows, the water being pumped by Newcomen steam engines . The Newcomen engines were not attached directly to the blowing cylinders because the engines alone could not produce a steady air blast. Abraham Darby III installed similar steam-pumped, water-powered blowing cylinders at the Dale Company when he took control in 1768. The Dale Company used several Newcomen engines to drain its mines and made parts for engines which it sold throughout

13068-663: Was becoming more common by the late 1830s, as in Jérôme-Adolphe Blanqui 's description in 1837 of la révolution industrielle . Friedrich Engels in The Condition of the Working Class in England in 1844 spoke of "an industrial revolution, a revolution which at the same time changed the whole of civil society". Although Engels wrote his book in the 1840s, it was not translated into English until

13189-414: Was converted to wrought iron. Conversion of cast iron had long been done in a finery forge . An improved refining process known as potting and stamping was developed, but this was superseded by Henry Cort 's puddling process. Cort developed two significant iron manufacturing processes: rolling in 1783 and puddling in 1784. Puddling produced a structural grade iron at a relatively low cost. Puddling

13310-566: Was cut off to eliminate competition. In order to promote manufacturing, the Crown paid for models of Lombe's machinery which were exhibited in the Tower of London . Parts of India, China, Central America, South America, and the Middle East have a long history of hand manufacturing cotton textiles, which became a major industry sometime after 1000 AD. In tropical and subtropical regions where it

13431-403: Was designed by John Smeaton . Cast iron cylinders for use with a piston were difficult to manufacture; the cylinders had to be free of holes and had to be machined smooth and straight to remove any warping. James Watt had great difficulty trying to have a cylinder made for his first steam engine. In 1774 Wilkinson invented a precision boring machine for boring cylinders. After Wilkinson bored

13552-559: Was done by hand in workers' homes or occasionally in master weavers' shops. Wages in Lancashire were about six times those in India in 1770 when overall productivity in Britain was about three times higher than in India. In 1787, raw cotton consumption was 22 million pounds, most of which was cleaned, carded, and spun on machines. The British textile industry used 52 million pounds of cotton in 1800, which increased to 588 million pounds in 1850. The share of value added by

13673-544: Was followed by a period of colonialism beginning around the 16th century. Following the discovery of a trade route to India around southern Africa by the Portuguese, the British founded the East India Company , along with smaller companies of different nationalities which established trading posts and employed agents to engage in trade throughout the Indian Ocean region. One of the largest segments of this trade

13794-569: Was grown, most was grown by small farmers alongside their food crops and was spun and woven in households, largely for domestic consumption. In the 15th century, China began to require households to pay part of their taxes in cotton cloth. By the 17th century, almost all Chinese wore cotton clothing. Almost everywhere cotton cloth could be used as a medium of exchange . In India, a significant amount of cotton textiles were manufactured for distant markets, often produced by professional weavers. Some merchants also owned small weaving workshops. India produced

13915-479: Was improved by Richard Roberts in 1822, and these were produced in large numbers by Roberts, Hill & Co. Roberts was additionally a maker of high-quality machine tools and a pioneer in the use of jigs and gauges for precision workshop measurement. The demand for cotton presented an opportunity to planters in the Southern United States, who thought upland cotton would be a profitable crop if

14036-660: Was in cotton textiles, which were purchased in India and sold in Southeast Asia , including the Indonesian archipelago where spices were purchased for sale to Southeast Asia and Europe. By the mid-1760s, cloth was over three-quarters of the East India Company's exports. Indian textiles were in demand in the North Atlantic region of Europe where previously only wool and linen were available; however,

14157-400: Was later used in the first cotton spinning mill . In 1764, in the village of Stanhill, Lancashire, James Hargreaves invented the spinning jenny , which he patented in 1770. It was the first practical spinning frame with multiple spindles. The jenny worked in a similar manner to the spinning wheel, by first clamping down on the fibres, then by drawing them out, followed by twisting. It was

14278-437: Was made by the bloomery process, which was the predominant iron smelting process until the late 18th century. In the UK in 1720, there were 20,500 tons of cast iron produced with charcoal and 400 tons with coke. In 1750 charcoal iron production was 24,500 and coke iron was 2,500 tons. In 1788, the production of charcoal cast iron was 14,000 tons while coke iron production was 54,000 tons. In 1806, charcoal cast iron production

14399-419: Was met by a domestic industry based around Lancashire that produced fustian , a cloth with flax warp and cotton weft . Flax was used for the warp because wheel-spun cotton did not have sufficient strength, but the resulting blend was not as soft as 100% cotton and was more difficult to sew. On the eve of the Industrial Revolution, spinning and weaving were done in households, for domestic consumption, and as

14520-413: Was overcome by the steam engine. Use of coal in iron smelting started somewhat before the Industrial Revolution, based on innovations by Clement Clerke and others from 1678, using coal reverberatory furnaces known as cupolas. These were operated by the flames playing on the ore and charcoal or coke mixture, reducing the oxide to metal. This has the advantage that impurities (such as sulphur ash) in

14641-425: Was produced on machinery invented in Britain. In 1788, there were 50,000 spindles in Britain, rising to 7 million over the next 30 years. The earliest European attempts at mechanised spinning were with wool; however, wool spinning proved more difficult to mechanise than cotton. Productivity improvement in wool spinning during the Industrial Revolution was significant but far less than that of cotton. Arguably

#787212