Ferrite (α-iron, δ-iron) Austenite (γ-iron) Pearlite (88% ferrite, 12% cementite) Martensite Bainite Ledeburite (ferrite-cementite eutectic, 4.3% carbon) Cementite (iron carbide, Fe3C) |
| Steel classes |
Alloy steel (contains non-carbon elements)
|
| Other iron-based materials |
Cast iron (>2.1% carbon) Wrought iron (contains slag) |
Thursday, September 23, 2010
IRON Alloy Phases
Saturday, September 18, 2010
There is little bit of steel in one's life
Iron and steel in history
It is believed that iron in pre-historic times may have been obtained from fragments of meteorites and it remained a rare metal for many centuries. Even after man learned how to extract iron from its ores, the product probably was so relatively soft and unpredictable, that bronze continued to be preferred for tools and weapons. Eventually iron replaced the non-ferrous metal for these purposes when man learned how to master the difficult arts of smelting, forging, hardening and tempering iron.
Man's use of iron in antiquity is attested by references to the metal in fragmentary writing and inscriptions from the ancient civilizations of Babylon, Egypt, China, India, Greece and Rome. Archeological finds in Mesopotamia and Egypt are proof that iron, and later steel, have been in the service of mankind for almost 6000 years. In early times, iron was melted with the use of charcoal made from wood. Later coal was discovered as a great source of heat. Subsequently, it was converted into coke, which was found to be ideal for smelting of iron ore.
Iron kept its dominant position for around 200 or more years after the Saugus works, the first successful iron works in America, was founded in 1646. With the advance of the Industrial Revolution, iron formed the rails for the newly invented railroad trains. It was also used to armour the sides of the fighting ships. About the mid-19th century, the age of steel began with the invention of the Bessemer process (1856), which allowed steel to be made in large quantities and at reasonable cost.
Use of iron in ancient India
Indian history is also full of references to the use of iron and steel. Some of the ancient monuments like the famous Iron pillar in New Delhi or the massive beams used in the Sun Temple at Konark bear ample testimony to the technological excellence of ancient Indian metallurgists.
The use of iron in India goes back to the ancient era. Vedic literary sources such as the Rig Veda, the Atharva Veda, the Puranas and epics are filled with references to iron and to its uses in peace and war. According to one of the studies, iron has been produced in India for over 3000 years in primitive, small-scale facilities.
Some milestones in iron and steel in Indian history
326 BC Porus presented Alexander 30 lbs of Indian iron
300 BC Kautilya (Chanakya) showed knowledge of minerals, including iron ores, and the art of extracting metals in 'Arthshastra'.
320 AD A 16-meter Iron pillar erected at Dhar, ancient capital of Malwa (near Indore).
330-380 AD Iron pillar in memory of Chandragupta II erected near Delhi. This solid shaft of wrought iron is about 8 meters in height and has dia. 0.32 to 0.46m.
13th century Massive iron beams used in the construction of the Sun temple, Konark
16th century Indian steel known as 'Wootz' of watery appearance used in the Middle East and Europe
17th century Manufacture of cannons, firearms and swords and agricultural implements
1830 Suspension bridge built over the Beas at Saugor with iron from Tendulkhma (MP). JM Heath built iron smelter at Porto Nova, Madras Presidency
1870 Bengal Iron works established at Kulti
1907 Tata Iron & Steel Company formed
1953 Indian Government entered into agreement with Krupp Demag, Federal Republic of Germany to set up steel plant at Rourkela
1954 Hindustan Steel Limited formed to construct and manage three integrated steel plants at Rourkela, Durgapur and Bhilai
1956 Second Industrial Policy resolution vested the state with the exclusive responsibility for developing industries, including iron and steel, and the term Public
Sector came into use for these
1960 Alloy steels plant installed at Durgapur
1965 Government of India signed agreement to establish steel plant at Bokaro
1973 Steel Authority of India Limited formed on 24th January
2006 IISCO merged with SAIL. Renamed IISCO Steel Plant.
Global Scenario
World's total crude steel production grew at a slower rate during the first half of this century and the growth rate picked up at a significant rate after the second world war:
It is believed that iron in pre-historic times may have been obtained from fragments of meteorites and it remained a rare metal for many centuries. Even after man learned how to extract iron from its ores, the product probably was so relatively soft and unpredictable, that bronze continued to be preferred for tools and weapons. Eventually iron replaced the non-ferrous metal for these purposes when man learned how to master the difficult arts of smelting, forging, hardening and tempering iron.
Man's use of iron in antiquity is attested by references to the metal in fragmentary writing and inscriptions from the ancient civilizations of Babylon, Egypt, China, India, Greece and Rome. Archeological finds in Mesopotamia and Egypt are proof that iron, and later steel, have been in the service of mankind for almost 6000 years. In early times, iron was melted with the use of charcoal made from wood. Later coal was discovered as a great source of heat. Subsequently, it was converted into coke, which was found to be ideal for smelting of iron ore.
Iron kept its dominant position for around 200 or more years after the Saugus works, the first successful iron works in America, was founded in 1646. With the advance of the Industrial Revolution, iron formed the rails for the newly invented railroad trains. It was also used to armour the sides of the fighting ships. About the mid-19th century, the age of steel began with the invention of the Bessemer process (1856), which allowed steel to be made in large quantities and at reasonable cost.
Use of iron in ancient India
Indian history is also full of references to the use of iron and steel. Some of the ancient monuments like the famous Iron pillar in New Delhi or the massive beams used in the Sun Temple at Konark bear ample testimony to the technological excellence of ancient Indian metallurgists.
The use of iron in India goes back to the ancient era. Vedic literary sources such as the Rig Veda, the Atharva Veda, the Puranas and epics are filled with references to iron and to its uses in peace and war. According to one of the studies, iron has been produced in India for over 3000 years in primitive, small-scale facilities.
Some milestones in iron and steel in Indian history
326 BC Porus presented Alexander 30 lbs of Indian iron
300 BC Kautilya (Chanakya) showed knowledge of minerals, including iron ores, and the art of extracting metals in 'Arthshastra'.
320 AD A 16-meter Iron pillar erected at Dhar, ancient capital of Malwa (near Indore).
330-380 AD Iron pillar in memory of Chandragupta II erected near Delhi. This solid shaft of wrought iron is about 8 meters in height and has dia. 0.32 to 0.46m.
13th century Massive iron beams used in the construction of the Sun temple, Konark
16th century Indian steel known as 'Wootz' of watery appearance used in the Middle East and Europe
17th century Manufacture of cannons, firearms and swords and agricultural implements
1830 Suspension bridge built over the Beas at Saugor with iron from Tendulkhma (MP). JM Heath built iron smelter at Porto Nova, Madras Presidency
1870 Bengal Iron works established at Kulti
1907 Tata Iron & Steel Company formed
1953 Indian Government entered into agreement with Krupp Demag, Federal Republic of Germany to set up steel plant at Rourkela
1954 Hindustan Steel Limited formed to construct and manage three integrated steel plants at Rourkela, Durgapur and Bhilai
1956 Second Industrial Policy resolution vested the state with the exclusive responsibility for developing industries, including iron and steel, and the term Public
Sector came into use for these
1960 Alloy steels plant installed at Durgapur
1965 Government of India signed agreement to establish steel plant at Bokaro
1973 Steel Authority of India Limited formed on 24th January
2006 IISCO merged with SAIL. Renamed IISCO Steel Plant.
Global Scenario
World's total crude steel production grew at a slower rate during the first half of this century and the growth rate picked up at a significant rate after the second world war:
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