Cementation process
Encyclopedia
The cementation process is an obsolete technique for making steel
by carburization
of iron
. Unlike modern steelmaking
, it increased the amount of carbon
in the iron. It was apparently developed before the 17th century. Derwentcote Steel Furnace, built in 1720, is the earliest surviving example of a cementation furnace. Another example
in Great Britain is the one on Doncaster Street in Sheffield
.
in 1574. It was again invented by Johann Nussbaum of Magdeburg
, who began operations at Nuremberg
(with partners) in 1601. The process was patented in England
by William Ellyot and Mathias Meysey in 1614. At that date, the "invention" could consist merely of the introduction of a new industry or product, or even a mere monopoly
. They evidently soon transferred the patent to Sir Basil Brooke
, but he was forced to surrender it in 1619. A clause in the patent prohibiting the import of steel
was found to be undesirable because he could not supply as much good steel as was needed.
Brooke's furnace
s were probably in his manor of Madeley
at Coalbrookdale
(which certainly existed before the English Civil War
) where two cementation furnaces have been excavated. He probably used bar iron from the Forest of Dean
, where he was a partner in farming the King's ironworks there at two periods. By 1631, it was recognised that Swedish iron was the best raw material and then or later particularly certain marks (brands) such as double bullett from Österby
(so called from the mark OO) and Leufsta (now Lövsta), whose hoop L mark consisted of an L in a circle, both belonging to Louis De Geer
and his descendants. These were among the first ironworks in Sweden
to use the Walloon process of fining
iron, producing what was known in England as oregrounds iron
. It was so called from the Swedish port of Öregrund
, north of Stockholm, in whose hinterland most of the ironworks lay. The ore used came ultimately from the Dannemora
mine.
and charcoal
. It uses one or more long stone pots inside a furnace. Typically, in Sheffield
, each was 14 feet by 4 feet and 3.5 feet deep. Iron bars and charcoal are packed in alternating layers, with a top layer of charcoal and then refractory matter to make the pot or "coffin" airtight. Some manufacturers used a mix of powdered charcoal, soot
and mineral salt
s, called cement powder. In larger works up to 16 tons of iron was treated in each cycle.
Depending on the thickness of the iron bars, the pots were then heated from below for a week or more. Bars were regularly examined and when the correct condition was reached the heat was withdrawn and the pots were left until cool—usually around fourteen days. The iron had "gained" a little over 1% in mass from the carbon
in the charcoal, and had become heterogeneous bars of blister steel.
The bars were then shortened, bound, heated and hammered, pressed or rolled to become shear steel. Alternatively they could be broken up and melted in a crucible using a crucible furnace
with a flux
to become crucible steel
or cast steel, a process devised by Benjamin Huntsman
in the 1740s.
, an alloy
of copper
and zinc
, was usually produced by a cementation process in which metallic copper
was heated with calamine
, a zinc ore. For details of this see calamine brass
.
Steel
Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...
by carburization
Carburization
Carburizing, spelled carburising in the UK, is a heat treatment process in which iron or steel is heated in the presence of another material which liberates carbon as it decomposes. Depending on the amount of time and temperature, the affected area can vary in carbon content...
of iron
Iron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...
. Unlike modern steelmaking
Steelmaking
Steelmaking is the second step in producing steel from iron ore. In this stage, impurities such as sulfur, phosphorus, and excess carbon are removed from the raw iron, and alloying elements such as manganese, nickel, chromium and vanadium are added to produce the exact steel required.-Older...
, it increased the amount of carbon
Carbon
Carbon is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds...
in the iron. It was apparently developed before the 17th century. Derwentcote Steel Furnace, built in 1720, is the earliest surviving example of a cementation furnace. Another example
Cementation furnace, Sheffield
The Cementation furnace in Sheffield, South Yorkshire, England is a Grade II Listed Building and is the only example of this type of steel making furnace to survive intact in Great Britain...
in Great Britain is the one on Doncaster Street in Sheffield
Sheffield
Sheffield is a city and metropolitan borough of South Yorkshire, England. Its name derives from the River Sheaf, which runs through the city. Historically a part of the West Riding of Yorkshire, and with some of its southern suburbs annexed from Derbyshire, the city has grown from its largely...
.
Origins
The process was described in a treatise published in PraguePrague
Prague is the capital and largest city of the Czech Republic. Situated in the north-west of the country on the Vltava river, the city is home to about 1.3 million people, while its metropolitan area is estimated to have a population of over 2.3 million...
in 1574. It was again invented by Johann Nussbaum of Magdeburg
Magdeburg
Magdeburg , is the largest city and the capital city of the Bundesland of Saxony-Anhalt, Germany. Magdeburg is situated on the Elbe River and was one of the most important medieval cities of Europe....
, who began operations at Nuremberg
Nuremberg
Nuremberg[p] is a city in the German state of Bavaria, in the administrative region of Middle Franconia. Situated on the Pegnitz river and the Rhine–Main–Danube Canal, it is located about north of Munich and is Franconia's largest city. The population is 505,664...
(with partners) in 1601. The process was patented in England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
by William Ellyot and Mathias Meysey in 1614. At that date, the "invention" could consist merely of the introduction of a new industry or product, or even a mere monopoly
Monopoly
A monopoly exists when a specific person or enterprise is the only supplier of a particular commodity...
. They evidently soon transferred the patent to Sir Basil Brooke
Basil Brooke (metallurgist)
Sir Basil Brooke , English metallurgist and recusant, inherited the manor of Madeley from his father. This contained iron and steel works and coal mines...
, but he was forced to surrender it in 1619. A clause in the patent prohibiting the import of steel
Steel
Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...
was found to be undesirable because he could not supply as much good steel as was needed.
Brooke's furnace
Furnace
A furnace is a device used for heating. The name derives from Latin fornax, oven.In American English and Canadian English, the term furnace on its own is generally used to describe household heating systems based on a central furnace , and sometimes as a synonym for kiln, a device used in the...
s were probably in his manor of Madeley
Madeley, Shropshire
Madeley is a town and civil parish in Shropshire, England, now part of the new town of Telford. The parish had a population of 17,935 at the 2001 census.Madeley is recorded in the Domesday Book, having been founded before the 8th century...
at Coalbrookdale
Coalbrookdale
Coalbrookdale is a village in the Ironbridge Gorge in Shropshire, England, containing a settlement of great significance in the history of iron ore smelting. This is where iron ore was first smelted by Abraham Darby using easily mined "coking coal". The coal was drawn from drift mines in the sides...
(which certainly existed before the English Civil War
English Civil War
The English Civil War was a series of armed conflicts and political machinations between Parliamentarians and Royalists...
) where two cementation furnaces have been excavated. He probably used bar iron from the Forest of Dean
Forest of Dean
The Forest of Dean is a geographical, historical and cultural region in the western part of the county of Gloucestershire, England. The forest is a roughly triangular plateau bounded by the River Wye to the west and north, the River Severn to the south, and the City of Gloucester to the east.The...
, where he was a partner in farming the King's ironworks there at two periods. By 1631, it was recognised that Swedish iron was the best raw material and then or later particularly certain marks (brands) such as double bullett from Österby
Österby
Österby is a village in Noarootsi Parish, Lääne County, in western Estonia....
(so called from the mark OO) and Leufsta (now Lövsta), whose hoop L mark consisted of an L in a circle, both belonging to Louis De Geer
Louis De Geer (1587-1652)
Louis De Geer was a Walloon/Dutch merchant and industrialist. He is considered the father of Swedish industry for introducing Walloon blast furnaces in Sweden...
and his descendants. These were among the first ironworks in Sweden
Sweden
Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....
to use the Walloon process of fining
Finery forge
Iron tapped from the blast furnace is pig iron, and contains significant amounts of carbon and silicon. To produce malleable wrought iron, it needs to undergo a further process. In the early modern period, this was carried out in a finery forge....
iron, producing what was known in England as oregrounds iron
Oregrounds iron
Oregrounds iron was a grade of iron that was regarded as the best grade available in 18th century England. The term was derived from the small Swedish city of Öregrund. The process to create it is known as the Walloon method....
. It was so called from the Swedish port of Öregrund
Öregrund
Öregrund is a locality situated in Östhammar Municipality, Uppsala County, Sweden with 1,555 inhabitants in 2010. It is located by the coast of the Baltic Sea. Öregrund is, despite its small population, for historical reasons often still referred to as a city.- History :The town was granted a royal...
, north of Stockholm, in whose hinterland most of the ironworks lay. The ore used came ultimately from the Dannemora
Dannemora, Sweden
Dannemora is an old mining town and a locality situated in Östhammar Municipality, Uppsala County, Sweden with 238 inhabitants in 2005.-Dannemora mine:...
mine.
Process
The process begins with wrought ironWrought iron
thumb|The [[Eiffel tower]] is constructed from [[puddle iron]], a form of wrought ironWrought iron is an iron alloy with a very low carbon...
and charcoal
Charcoal
Charcoal is the dark grey residue consisting of carbon, and any remaining ash, obtained by removing water and other volatile constituents from animal and vegetation substances. Charcoal is usually produced by slow pyrolysis, the heating of wood or other substances in the absence of oxygen...
. It uses one or more long stone pots inside a furnace. Typically, in Sheffield
Sheffield
Sheffield is a city and metropolitan borough of South Yorkshire, England. Its name derives from the River Sheaf, which runs through the city. Historically a part of the West Riding of Yorkshire, and with some of its southern suburbs annexed from Derbyshire, the city has grown from its largely...
, each was 14 feet by 4 feet and 3.5 feet deep. Iron bars and charcoal are packed in alternating layers, with a top layer of charcoal and then refractory matter to make the pot or "coffin" airtight. Some manufacturers used a mix of powdered charcoal, soot
Soot
Soot is a general term that refers to impure carbon particles resulting from the incomplete combustion of a hydrocarbon. It is more properly restricted to the product of the gas-phase combustion process but is commonly extended to include the residual pyrolyzed fuel particles such as cenospheres,...
and mineral salt
Salt
In chemistry, salts are ionic compounds that result from the neutralization reaction of an acid and a base. They are composed of cations and anions so that the product is electrically neutral...
s, called cement powder. In larger works up to 16 tons of iron was treated in each cycle.
Depending on the thickness of the iron bars, the pots were then heated from below for a week or more. Bars were regularly examined and when the correct condition was reached the heat was withdrawn and the pots were left until cool—usually around fourteen days. The iron had "gained" a little over 1% in mass from the carbon
Carbon
Carbon is the chemical element with symbol C and atomic number 6. As a member of group 14 on the periodic table, it is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds...
in the charcoal, and had become heterogeneous bars of blister steel.
The bars were then shortened, bound, heated and hammered, pressed or rolled to become shear steel. Alternatively they could be broken up and melted in a crucible using a crucible furnace
Crucible steel
Crucible steel describes a number of different techniques for making steel in a crucible. Its manufacture is essentially a refining process which is dependent on preexisting furnace products...
with a flux
Flux (metallurgy)
In metallurgy, a flux , is a chemical cleaning agent, flowing agent, or purifying agent. Fluxes may have more than one function at a time...
to become crucible steel
Crucible steel
Crucible steel describes a number of different techniques for making steel in a crucible. Its manufacture is essentially a refining process which is dependent on preexisting furnace products...
or cast steel, a process devised by Benjamin Huntsman
Benjamin Huntsman
Benjamin Huntsman was an English inventor and manufacturer of cast or crucible steel.-Biography:Huntsman was born the third son of a Quaker farmer in Epworth, Lincolnshire. His parents were Germans who had emigrated only a few years before his birth.Huntsman started business as a clock, lock and...
in the 1740s.
Cementation process for brass
In the early modern period, brassBrass
Brass is an alloy of copper and zinc; the proportions of zinc and copper can be varied to create a range of brasses with varying properties.In comparison, bronze is principally an alloy of copper and tin...
, an alloy
Alloy
An alloy is a mixture or metallic solid solution composed of two or more elements. Complete solid solution alloys give single solid phase microstructure, while partial solutions give two or more phases that may or may not be homogeneous in distribution, depending on thermal history...
of copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
and zinc
Zinc
Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...
, was usually produced by a cementation process in which metallic copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
was heated with calamine
Calamine (mineral)
Calamine is a historic name for an ore of zinc. The name calamine was derived from the Belgian town of Kelmis, whose French name is "La Calamine", which is home to a zinc mine...
, a zinc ore. For details of this see calamine brass
Calamine brass
Calamine brass is brass produced by a particular alloying technique using the zinc ore calamine directly, rather than first refining it to metallic zinc...
.