2. Iron is a chemical element with the
symbol Fe (from latin: ferrum) and atomic
number 26. It is a metal in the first transition
series. It is the most common element (by mass)
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. Iron's
very common presence in rocky planets like Earth
is due to its abundant production as a result of
fusion in high-mass stars, where the production
of nickel-56 (which decays to the most common
isotope of iron) is the lastnuclear fusion
reaction that is exothermic. This causes
radioactive nickel to become the last element to
be produced before collapse of a supernova leads
to the explosive events that scatter
this precursor radionuclide of iron abundantly
into space.
3. The mechanical properties of iron and its alloys can be evaluated
using a variety of tests, including the Brinell test, Rockwell
test and the Vickers hardness test. The data on iron is so
consistent that it is often used to calibrate measurements or to
compare tests.However, the mechanical properties of iron are
significantly affected by the sample's purity: pure research-purpose
single crystals of iron are actually softer than aluminium, and the
purest industrially produced iron (99.99%) has a hardness of 20–
30 Brinell.An increase in the carbon content of the iron will
initially cause a significant corresponding increase in the iron's
hardness and tensile strength. Maximum hardness of is achieved with
a 0.6% carbon content, although this produces a metal with a low
tensile strength.
4. The Wealden iron industry was located in
the Weald of south-eastern England. It
was formerly an important industry,
producing a large proportion of the bar
iron made in England in the 16th century
and most British cannon until about 1770.
Ironmaking in the Weald
used ironstone from various clay beds,
and was fuelled by charcoal made from
trees in the heavily wooded landscape.
The industry in the Weald declined when
ironmaking began to be fuelled
by coke made from coal, which does not
occur accessibly in the area.
5. Iron ore in the form of siderite, commonly known as iron stone or historically as
mine, occurs in patches or bands in the Cretaceous clays of the Weald. Differing
qualities of ore were extracted and mixed by experienced smelters to give the best
results. Sites of opencast quarries survive from the pre-Roman and Roman eras, but
medieval ore extraction was mainly done by digging a series of minepits about five
metres in diameter and up to twelve metres deep with material being winched up in
baskets suspended from a wooden tripod. This was less destructive of the land as
spoil from one pit was used to backfill the previous pit allowing continued land use.
The fuel for smelting was charcoal, which needed to be produced as close as possible
to the smelting sites because it would crumble to dust if transported far by cart over
rough tracks. Wood was also needed for pre-roasting the ore on open fires, a process
which broke down the lumps or nodules and converted the carbonate into oxide.
Large areas of woodland were available in the Weald and coppicing woodlands could
provide a sustainable source of wood. Sustainable charcoal production for a post-
medieval blast furnace required the timber production from a 3 miles (4.8 km) radius
of a furnace in a landscape that was a quarter to a third wooded. Forging and
finishing of the iron from bloomeries and blast furnaces also required large quantities
of charcoal and was usually carried out at a separate site.
6. Ferrous metallurgy began far back in prehistory.The earliest
surviving iron artifacts, from the 5th millennium BC in Iran and 2nd
millennium BC in China, were made from meteoritic iron-nickel. By the
end of the 2nd millennium BC iron was being produced fromiron
ores from South of the Saharan Africa to China.The use of wrought iron
was known in the 1st millennium BC. During the medieval period,
means were found in Europe of producing wrought iron from cast
iron (in this context known as pig iron) usingfinery forges. For all these
processes, charcoal was required as fuel.
Steel (with a smaller carbon content than pig iron but more than wrought iron) was
first produced in antiquity. New methods of producing it by carburizing bars of iron in
the cementation process were devised in the 17th century. In the Industrial
Revolution, new methods of producing bar iron without charcoal were devised and
these were later applied to produce steel. In the late 1850s,Henry Bessemer invented
a new steelmaking process, involving blowing air through molten pig iron, to produce
mild steel.This and other 19th century and later processes have led to wrought iron
no longer being produced
7. A nativemetalis any metal that is found in its metallic form,
either pure or as an alloy, in nature. Metals that can be found
as native deposits singly and/or in alloys
include aluminium, antimony, arsenic, bismuth, cadmium, ch
romium, cobalt, indium, iron,nickel, selenium, tantalum, tellu
rium, tin, titanium, and zinc, as well as two groups of metals:
the gold group, and the platinum group. The gold group
consists of gold, copper, lead, aluminium,mercury, and silver.
The platinum group consists
of platinum, iridium,osmium, palladium, rhodium,
and ruthenium.
8. Iron industry of Ashdown Forest
Ashdown Forest formed an important part of the Wealden iron
industry that operated from pre-Roman times until the early 18th
century. The industry reached its peak in the two periods when the
Weald was the main iron-producing region of Britain, namely in the
first 200 years of the Roman occupation (1st to 3rd centuries AD) and
during Tudor and early Stuart times. Iron-smelting in the former
period was based on bloomery technology, while the latter depended for
its rapid growth on the blast furnace, when the Ashdown area became
the first in England to use this technology.
The Forest was a particularly favourable location for iron production
because of the presence of iron-ore in the local geology of sandstone
Ashdown Beds and overlying Wadhurst Clay, the availability of large
expanses of woodland for the production of charcoal, and deep, steep-
sided valleys that had been incised into the relatively soft sandstone
which together with locally high rainfall made it practical to dam
streams to form lakes to provide water power for furnaces and forges.
9. Cleere , Henry (1978). Roman Sussex—TheWeald. In Drewett (1978),
pp. 59–63.
Drewett, Peter, ed. (1978). Archaeology in Sussex to AD 1500.
London: Council for British Archaeology, Research Report 29.
Hodgkinson, Jeremy (2008). TheWealden Iron Industry. Stroud:The
History Press. ISBN 978-0-7524-4573-1.
Leslie, Kim; Short, Brian (1999). An Historical Atlas of Sussex.
Chichester: Phillimore & Co Ltd. ISBN 1-86077-112-2.
Rackham, Oliver (1997). The Illustrated History of the Countryside.
London: Orion Publishing Group. ISBN 1-85799-953-3.
Tebbutt, C.F. (1982) A Middle-Saxon Iron Smelting Furnace Site at
Millbrook, Ashdown Forest, Sussex. Sussex Archaeological
Collections, 120, 19-35
10. Steel is an alloy made by combining iron and other
elements, the most common of these being carbon.
When carbon is used, its content in the steel is
between 0.2% and 2.1% by weight, depending on
the grade. Other alloying elements sometimes used
are manganese, chromium, vanadim and tungsten.
11. Iron is found in the Earth's crust only in the form of an ore,
usually an iron oxide, such as magnetite, hematite etc.
Iron is extracted from iron ore by removing the oxygen
and combining the ore with a preferred chemical partner
such as carbon.This process, known as smelting, was first
applied to metals with lower melting points, such as tin,
which melts at approximately 250 °C (482 °F)and copper,
which melts at approximately 1,100 °C (2,010 °F). In
comparison, cast iron melts at approximately 1,375
°C(2,507 °F).
12. It is common todayto talkabout "the iron and steel
industry"as if it were a single entity, but historically
theywere separateproducts. The steel industryis
often consideredto be an indicator of economic
progress, because of the critical role played by steel
in infrastructuraland overall economic development
13. Modern steels are made with
varying combinations of alloy
metals to fulfill many purposes.
Carbon steel, composed simply of
iron and carbon, accounts for 90%
of steel production. High strength
low alloy steel has small additions
(usually < 2% by weight) of other
elements, typically 1.5%
manganese, to provide additional
strength for a modest price
increase
14. ron and steel are used widely in the
construction of roads, railways,
other infrastructure, appliances,
and buildings. Most large modern
structures, such
as stadiums and skyscrapers, bridg
es, and airports, are supported by a
steel skeleton. Even those with a
concrete structure will employ steel
for reinforcing. In addition, it sees
widespread use in major appliances
and cars. Despite growth in usage
of aluminium, it is still the main
material for car bodies. Steel is
used in a variety of
other construction materials, such
as bolts, nails, and screws.
15. The Steel industry in Chinahas developed over
several decades into the worldbiggest.China
accounted for 36.4%of world steel production in
2007. It has driven by rapid modernisation of its
economy, construction, infrastructure and
manufacturing industries.
16. Steel in Africa dates to
prehistory, and continues to be
manufactured presently in many
countries. In 2009 Africa
accounted for 1.3% of global steel
production or 15.2 million metric
tons.2009 was the lowest steel
production in Africa in 6 years,
both in terms of absolute
quantity and percentage of
global production.
