The history of joining metals goes back several millennia. The ancient Greek historian Herodotus mentions that 'iron welding' was invented in the 5th century BCE. And the Iron pillar of Delhi, weighing 5.4 metric tons, was erected about 310 CE.
The ancient art of forge welding, in which blacksmiths pounded hot metal until bonding occurred, was improved during the Middle Ages and, in 1540, Vannoccio Biringuccio published descriptions of the forging operation, particularly the welding of hoops for wagon wheels and barrels.
In 1800, Sir Humphry Davy discovered the short-pulse electrical arc and independently, in 1803, Russian scientist Vasily Petrov published news of a continuous electric arc and suggested its use for melting metals.
Until the 19th century, the only welding process was forge welding, where metals were joined by heating and hammering. Steel ships, locomotives, bridges and steam engine boilers for the Industrial Revolution were assembled by rivetting plates of steel together, a painstaking process of drilling rows of holes through two plates inserting a red hot rivet and then hammering the end of the rivet into a neat hemisphere. The process was made a little less arduous with the use of compressed air hammers.
In 1882 inventors Nikolai Benardos (Russian) and Stanisław Olszewski (Polish) created the first electric arc welding method using carbon electrodes. Arc welding with metal electrodes was invented in Russia by Nikolai Slavyanov in 1888 and independently, in America, by C. L. Coffin in 1890.
About 1900, British engineer, A. P. Strohmenger, developed a coated metal electrode in Britain, which provided a more stable arc. In 1905, Russian scientist Vladimir Mitkevich proposed using a three-phase electric arc for welding and C. J. Holslag developed an alternating current system in 1919, but neither technique became popular until 1929.
In 1815, William Murdock developed a city lighting system for the city of London using coal gas burning lamps. To supply gas to the lamps Murdock made pipes by welding barrels of old discarded muskets. The demand for his lighting system created the need for long metal tubes.
In 1824, James Russell patented a technique of heating a flat iron strip until it was malleable, folding it into a tube so that the edges were pressed together and forged welded with a drop hammer. The tube was then finished by passing it through a grooved rolling mill. The following year, Comenius Whitehouse developed a simpler process where thin strips of iron were heated and drawn through a cone-shaped opening in a die.
Arc welding and oxy-fuel welding were developed late in the 19th century with electric resistance welding soon after. In 1911, John Moon built machinery to produce pipe in a continuous process by passing a steel strip through a series of grooved rollers that force the strip into a circular shape and finishing with arc welding electrodes.
As early as 1840, ironworkers were producing seamless tubes by drilling a hole through a solid cylindrical billet. The billet was then heated and drawn through a series of dies which elongated it to form a tube. In 1888, the solid billed was cast around a fireproof brick core. When it was cooled, the brick was removed leaving a hole in the middle.
These tubes were initially used for bicycle frames but the need for pipes and tubes increased with the automobile and oil industries.
French engineers Edmond Fouché and Charles Picard developed oxygen-acetylene welding in 1903. Oxy-fuel welding uses fuel gases or liquid fuels and pure oxygen to weld or cut metals. This melts a pool of molten metal and additional filler metal. Pure oxygen is used to increase the flame temperature to the melting point of steel. Propane/air flame burns at about 1,980 °C (3,590 °F), while a propane/oxygen flame burns at about 2,253 °C (4,087 °F). An oxyhydrogen flame burns at 2,800 °C (5,072 °F) and an acetylene/oxygen flame burns at about 3,500 °C (6,332 °F).
Acetylene (C2H2), a colourless gas widely used as a fuel, was accidentally discovered in 1836 by Edmund Davy, while attempting to isolate potassium metal, but it was not practical for welding until about 1900, when a suitable torch was developed. The torch had to supply controlled amounts of oxygen and acetylene gas from separate gas cylinders to a nozzle where it was ignited.
Initially, oxy/fuel welding was the only process capable of making high quality welds in most metals and it was popular because of its portability and relatively low cost. It was the most common method until the development of coated arc welding electrodes in the late 1920s. Since then, it has been superseded by various arc welding methods providing faster welding and the ability to weld titanium and other reactive metal.
However, oxy-acetylene is still used extensively when access to electricity is limited and also to cut steel by first heating it and then using a stream of oxygen to burn the iron into iron oxide.
Fuel/air torches are typically used for low temperature work such as soldering and brazing. The are incapable of melting most metals.
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