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Steel Authority Of India Ltd. Business Information, Profile, and History

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History of Steel Authority Of India Ltd.

The Steel Authority of India Ltd. (SAIL) was created in 1973 as the holding company and supervisory agency for those parts of the Indian iron and steel industry which are wholly within the public sector. Its main product, by volume, is iron ore, most of which is exported. It has a total production capacity of 11 million tons of steel per year, representing more than four-fifths of India's total capacity. It operates its own collieries, a special steels plant, and a foundry for pipes and castings.

The history of the iron and steel industry in modern India is closely bound up with political and economic developments since the country achieved independence from Britain in 1947. Most of the productive units now run by SAIL were built as state ventures with aid and assistance from industrially-developed countries, and operated by SAIL's predecessor, Hindustan Steel Ltd. SAIL's main subsidiary, the Indian Iron & Steel Co. Ltd., which is India's largest single iron and steel company, developed separately as a private company before nationalization, but it depended on state subsidies from 1951 onwards and had to function within the terms of the government's planning system.

However, the industry did not spring from nowhere in 1947. Iron had been produced in India for centuries, while Indian steel was superior in quality to British steel as late as 1810. With the consolidation of the British raj the indigenous industry declined and the commercial production of steel did not begin in earnest till 1913, when the Tata Iron and Steel Company began production at Sakchi, on foundations laid by Jamsetji Tata whose sons had raised the enormous sum of Rs23 million to set up the company, partly from family funds but mostly from Bombay merchants, several maharajahs, and other wealthy Indians who supported the movement for Indian self-sufficiency (Swadeshi) but did not want to appear openly anti-British. Tata was to dominate the Indian steel industry until the 1950s. The Indian Iron & Steel Company was set up in West Bengal in 1918 by the British firm Burn & Co., with plans to become a rival steelmaker. However, steel prices declined in the early 1920s and the company produced only pig iron until 1937. The acute depression suffered by the iron and steel industry after World War I was alleviated by the government's protective measures. The industry continued to make steady progress.

From the late 1920s, when the British authorities introduced a system of tariffs which protected British and Indian steel but raised barriers against imports from other countries, the Indian market was divided in the ratio of 70 to 30 between British producers on the one hand and the Tata company on the other--thus effectively excluding indigenous newcomers. By 1939 the Tata works were producing 75% of the steel consumed in what was then the Indian Empire, comprising the present-day India, Sri Lanka, Pakistan, Bangladesh, and Burma.

In the late 1930s, as European rearmament pushed iron and steel prices upward, the export of Indian pig iron increased and two small firms began to compete directly with the Tata company in steel production. The first was the Mysore State Iron Works, which had been set up by the maharajah of Mysore in 1923, to produce pig iron at Benkipur, now Bhadravati. The second was the Steel Corporation of Bengal, a subsidiary established by the Indian Iron & Steel Company in 1937, the year after it had bought up the assets of the bankrupted Bengal Iron and Steel Company. The Steel Corporation of Bengal was reabsorbed into its parent company in 1953. All three companies profited from the British connection during World War II. Annual output rose from 1 million tons in 1939 to an average of 1.4 million tons in 1940-1945.

In 1947, when India became independent as the biggest, but not the only, successor state to the British raj, the three major iron and steel companies had a total capacity of only 2.5 million tons. A great deal of their plant was already more than three decades old, and badly in need of repair and replacement, while demand for iron and steel was growing.

Like other Third World states that have achieved political independence but still find their economic prospects determined by their subordinate position in the world economy, the new republic's policymakers decided to seek economic growth through a combination of protection for domestic industries, heavy public investment in them, encouragement of savings to finance that investment, and state direction of production and pricing. The Mahalanobis model of the Indian economy, based on the assumptions that exports could not be rapidly increased and that present consumption should be curbed for the sake of longterm growth through import substitution by the capital goods sector, provided the theoretical justification for this set of policies, which closely resembled what was done in the Soviet Union in the 1930s, in China in the 1950s, and in Africa and Asia in the 1960s, though with much less loss of life than in most of these cases.

Under the terms of the new government's Industrial Policy Statement of 1948, confirmed in the Industries Development and Regulation Act three years later, new ventures in the iron and steel industry were to be undertaken only by the federal government, but existing ventures would be allowed to stay in the private sector for the first ten years. Thus the First Five Year Plan, from 1951-1956, involved the use of government funds to help Tata Iron and Steel and Indian Iron & Steel to expand and modernize while remaining in the private sector. As for new projects, in 1953 the government signed an agreement with the German steelmakers Krupp and Demag on creating a publicly owned integrated steel plant, which was sited at Rourkela, in the state of Orissa, to make use of iron ore mined at Barsua and Kalta. Krupp and Demag were chosen after the failure of Indian requests for aid from Britain and the United States, but were excluded from the project by 1959, when the Estimates Committee of the Lok Sabha, the lower house of the Indian Parliament, concluded that getting investment funds from them was equivalent to borrowing at an interest rate of 12%.

In order to carry out its side of the agreement the government set up Hindustan Steel Ltd. in 1954, as a wholly state-owned company responsible for the operation of the Rourkela plant. By 1959, when the plant was commissioned, Hindustan Steel had become responsible for two more plants, at Bhilai in Madhya Pradesh and at Durgapur in West Bengal, under the Second Five Year Plan, that started in 1956. The Bhilai plant, located between Bombay and Calcutta, was designed and equipped by Soviet technicians, under an agreement signed in 1955, and by 1961 it included six open-hearth furnaces with a total capacity of one million tons, supplied from iron ore mines at Rajhara and Dalli. The Durgapur plant, meanwhile, was built with assistance and advice from Britain and sited near the Bolani iron ore mine. Hindustan Steel took over the operation of all the iron ore mines supplying its plants, all three of which had been located to take advantage of existing supplies. This policy of locating steel production near raw materials sources reflected the relatively small and dispersed nature of the domestic market for steel at that time, and contrasted with the market-related location policies of companies in more advanced steel-producing countries, such as the United States.

Hindustan Steel's other major venture was its Alloy Steels Project, also based at Durgapur, which was inaugurated in 1964. Hindustan Steel's tasks included not only steel production but also the procurement of raw materials, and its subsidiaries included, besides the iron ore mines already mentioned, limestone and dolomite mines and coal washeries. It also operated a fertilizer plant at Rourkela.

The modernization of the two private sector leaders and the program of public sector investment together raised Indian steel output from about one million tons a year in the 1940s to three million tons in 1960, then to six million tons only four years later. Pig iron output rose by an even greater margin, from 1.6 million tons in 1950 to nearly 5 million tons in 1961. Both wings of the iron and steel industry contributed to the expansion of the engineering and machinery industries envisaged in the Mahalanobis model, and in turn were stimulated by the increased demand to raise production volume and quality. In 1965 Hindustan Steel's latest project, for an iron and steel plant with an associated township at Dhanbad in the state of Bihar, was transferred to a new company, Bokaro Steel Limited. Contact continued between the two companies, however, mainly through an arrangement whereby the chairman of each company was made a part-time director of the other. Like the Bhilai plant the Bokaro project was initiated with aid and advice from the Soviet Union, including blueprints, specialist equipment, technical training, and a loan at 2.5% interest. After the establishment of SAIL the Bokaro company was changed back into a division of the public sector steel company.

Throughout its first five years of production, 1958 to 1963, Hindustan Steel's losses rose steadily due to Rs7.51 million to Rs260 million it made a small profit in 1965 and 1966, only to slip back into the red and stay there until 1974, the last year of the company's existence under that name. Among the reasons the company gave for these disappointing results were the losses incurred at the Rourkela fertilizer plant, the Steel Alloys Project, and the Durgapur steel plant, an increased rate of interest on government loans, an increase in provision for depreciation, and the high costs of imported plant and equipment.

The rate of growth of the iron and steel industry, and of the engineering and machinery producing sectors with which its fate is so closely linked, declined significantly once the phase of import substitution was complete and the droughts of the mid-1960s had forced a diversion of resources from industry. Pig iron output, which had risen so spectacularly in the 1950s, rose from 7 million tons in 1965 to 10 million tons in 1985, while production of steel rose from 6 million tons to 12 million tons in the same period. The industry suffered due tostate intervention to keep its domestic prices low as an indirect subsidy to steel users, and--though the technical problems were different--from a heritage of outdated and inefficient plant and equipment.

Indian government policy since 1965 has been to use its iron ore less as a contribution to domestic growth than as an export, earning foreign exchange and helping to reduce the country's chronic deficit on its balance of trade. Production of ore increased, from 18 million tons in 1965 to 43 million tons in 1985, in order to supply a growing number of overseas markets.

With the expansion and diversification of Hindustan Steel, the separate establishment of Bokaro and the beginning of planning for new plants at Salem, Vishakhapatnam, and Vijaynagar, it became increasingly clear that public sector iron and steel production would need some new form of co-ordination to avoid duplication and to channel resources more effectively. The Steel Authority of India Ltd. was established in January 1973 for this purpose, to function as a holding company along the lines of similar but older bodies in Italy and Sweden. The new organization was placed on a secure footing when the Indian Iron & Steel Company was nationalized, giving SAIL control of all iron and steel production apart from the venerable Tata Iron and Steel Company and a number of small-scale electric-arc furnace units. At the time of nationalization the Indian Iron & Steel Company comprised a steel plant at Burnpur in West Bengal; iron ore mines at Gua and Manoharpur; coal mines at Ramnagore, Jitpur, and Chasnalla; and a specialist subsidiary, the IISCO-Ujjain Pipe and Foundry Co. Ltd., based at Kulti.

Both SAIL and its predecessor sought to expand capacity to meet predicted rises in demand for steel. In 1971 Hindustan Steel had unveiled plans for India's first coastal steel plant, at Vishakhapatnam. The project, which in 1991 was in the process of being opened, with one blast furnace already in operation, will probably allow productivity of 230 tons per man year compared with less than 50 in SAIL's existing plants. The Authority has also invested heavily in modernizing its oldest plants, at Rourkela and Durgapur.

The 1980s were not a happy decade for SAIL. It made losses between 1982 and 1984 but went back into the black in the following two years. Meanwhile Tata Iron & Steel was consistently profitable. By 1986, when the Indian steel industry's total capacity was 15.5 million tons, only 12.8 million were actually produced, of which SAIL produced 7.1 million. Thus imports of 1.5 million tons were needed to meet total demand, after years of exporting Indian steel. By 1988 all the main steel plants in India except Vishakhapatnam were burdened with obsolescent plant and equipment, and Indian steel prices were the highest in the world. The government proposed a ten-year plan to modernize the plants, based on aid from West Germany, Japan, and the Soviet Union just at a time when the worldwide economic recession was deepening and the World Bank was recommending the privatization of SAIL and the liberalization of steel imports.

In 1989 SAIL acquired Vivesvata Iron and Steel Ltd. In its first year under SAIL's wing this new subsidiary's production and turnover showed an improvement over its last year in the private sector. This progress contrasted with results for SAIL as a whole in 1989-1990, since production declined, and once again planned targets were not met. Various factors contributed to this disappointing outcome, including unrest at the Rourkela plant as a result of the management's decision not to negotiate with a new union, Rourkela Sramik Sangha, which had challenged the established union, Rourkela Mazdoor Sabha, and had even won all the seats on the plant's elected works committee. Another problem, continuing over several years, arose from defects in power supply; the impact of power-cuts on steel output in 1989-1990 was estimated as 170,000 tons lost, and the supply of coal was unreliable.

SAIL remains in the public sector as a central instrument of state plans for industrial development. The country's reserves of iron ore and other raw materials for iron and steel make the industry central to the economy. At the beginning of the 1980s India had recoverable reserves of iron ore amounting to 10.6 billion tons, a natural endowment which it would take 650 years to deplete at then-current rates of production. The high-grade ore within this total--that is, ore with an iron content of at least 65%--was, however, thought likely to reach depletion in only 42 years; yet it still represented about one-tenth of the world total. SAIL has had to struggle to maintain production, let alone expand it, largely because of circumstances outside its control. Since the purchase of raw materials has typically accounted for 30% of the Indian steel industry's production costs, any rise in the prices of coal, ferro-manganese, limestone, or iron ore will cut into the industry's profitability. In the first half of the 1980s, for example, prices for these materials rose by between 95 and 150%, at the same time as electricity charges rose by 150%. Most of these increases were imposed by other state enterprises. Nor has it helped SAIL that the high sulfur content of Indian coal has required heavy investment in desulfurization at its steel plants. Indeed, the industry has had chronic problems in trying to operate blast furnaces designed to take low-sulfur coking coal. The more suitable process of making sponge iron with non-coking coal, then converting it to steel in electric arc furnaces, was introduced in the private sector later, though by 1989 only 300,000 tons were being produced in this way. India's basic output costs of Rs6,420 per ton in 1986 compare well with the averages for West Germany (Rs6,438), for Japan (Rs7,898) and for the United States (Rs6,786). What finally keeps Indian steel from being competitive is the imposition of levies which raise its price per ton by about 30%, and which include excise duties, a freight capitalization surcharge, and a Steel Development Fund charge.

In spite of such problems, and in response to them, SAIL announced in December 1990 that it planned to increase its annual output of steel from 11 million to 19 million tons, thus transforming itself from the world's thirteenth largest steel producer to its third largest, within ten years. SAIL's use of its steel production capacity, running at about 77% in 1990, would be raised to 95% by 1996, thus permitting output of crude steel to rise by two-fifths over its current level. However, output for 1990 had actually been only 6 million tons, compared with 6.9 million tons in 1988, and 8 million tons in 1989. SAIL is no more able than large steel companies in other countries to achieve the optimum balance between demand and supply, between increasing the quantity of output and improving its quality by modernizing, and thus escaping from its heritage of outdated plant and equipment. Neither Hindustan Steel nor SAIL was ever in a position to defy the circumstances of the Indian economy or of the world steel industry on their own, but they have largely achieved the more modest goal of contributing to India's postwar economic growth.

Principal Subsidiaries: Indian Iron and Steel Company; IISCO-Ujjain Pipe and Foundry Co.Ltd.; Maharashtra Electrosmelt Ltd..

Related information about Steel

The chief alloy of iron, and the most used of all metals. It consists of iron hardened by the presence of a small proportion of carbon. It was made in small amounts in ancient times by heating cast-iron to reduce surface carbon, and was later made in crucibles in small quantities for tools. Steel production began in China before the 6th-c AD. Western large-scale manufacture for constructional purposes began with the Bessemer process (1856 onwards). Most steel used today is a simple carbon steel, but there exist many special steels formed by the addition of other metals, such as high alloy steels for tools, and stainless steel (with nickel and chromium).

otheruses
Steel is a metal alloy whose major component is iron, with carbon content between 0.02% and 1.7% by weight. Carbon is the most cost effective alloying material for iron, but many other alloying elements are also used. Carbon and other elements act as a hardening agent, preventing dislocations in the iron atom crystal lattice from sliding past one another. Varying the amount of alloying elements and their distribution in the steel controls qualities such as the hardness, elasticity, ductility, and tensile strength of the resulting steel. Steel with increased carbon content can be made harder and stronger than iron, but is also more brittle. Alloys with higher carbon content than this are known as cast iron because of their lower melting point. Steel is also to be distinguished from wrought iron with little or no carbon, usually less than 0.035%.

Iron and steel


Iron, like most metals, is not found in the Earth's crust in an elemental state. Iron can be found in the crust only in combination with oxygen or sulfur. Typically Fe2O3—the form of iron oxide (rust) found as the mineral hematite, and FeS2—Pyrite (fool's gold). This process, known as smelting, was first applied to metals with lower melting points. Copper melts at just over 1000 °C, while tin melts around 250 °C. Unlike copper and tin, liquid iron dissolves carbon quite readily, so that smelting results in an alloy containing too much carbon to be called steel.

Even in the narrow range of concentrations that make up steel, mixtures of carbon and iron can form into a number of different structures, or allotropes, with very different properties; At room temperature, the most stable form of iron is the body-centered cubic (BCC) structure ferrite or ?-iron, a fairly soft metallic material that can dissolve only a small concentration of carbon (no more than 0.021 wt% at 910 °C). Above 910 °C ferrite undergoes a phase transition from body-centered cubic to a face-centered cubic (FCC) structure, called austenite or ?-iron, which is similarly soft and metallic but can dissolve considerably more carbon (as much as 2.03 wt% carbon at 1154 °C). One way for carbon to leave the austenite is for cementite to precipitate out of the mix, leaving behind iron that is pure enough to take the form of ferrite, and resulting in a cementite-ferrite mixture. Self-reinforcing patterns often emerge during this process, leading to a patterned layering known as pearlite due to its pearl-like appearance, or the similar but less beautiful bainite.

Perhaps the most important allotrope is martensite, a chemically metastable substance with about four to five times the strength of ferrite. As such, it requires extremely little thermal activation energy to form.

The heat treatment process for most steels involves heating the alloy until austenite forms, then quenching the hot metal in water or oil, cooling it so rapidly that the transformation to ferrite or pearlite does not have time to take place. Internal stresses from this expansion generally take the form of compression on the crystals of martensite and tension on the remaining ferrite, with a fair amount of shear on both constituents. Nickel and manganese in steel add to its tensile strength and make austenite more chemically stable, chromium increases the hardness and melting temperature, and vanadium also increases the hardness while reducing the effects of metal fatigue. Large amounts of chromium and nickel (often 18% and 8%, respectively) are added to stainless steel so that a hard oxide forms on the metal surface to inhibit corrosion. Tungsten interferes with the formation of cementite, allowing martensite to form with slower quench rates, resulting in high speed steel. On the other hand sulfur, nitrogen, and phosphorus make steel more brittle, so these commonly found elements must be removed from the ore during processing.

When iron is smelted from its ore by commercial processes, it contains more carbon than is desirable.

History of iron and steelmaking



Iron was in limited use long before it became possible to smelt it. The first signs of iron use come from Ancient Egypt and Sumer, where around 4000 BC small items, such as the tips of spears and ornaments, were being fashioned from iron recovered from meteorites (see Iron: History). About 6% of meteorites are composed of an iron-nickel alloy, and iron recovered from meteorite falls allowed ancient peoples to manufacture small numbers of iron artifacts.

Meteoric iron was also fashioned into tools in precontact North America. Beginning around the year 1000, the Thule people of Greenland began making harpoons and other edged tools from pieces of the Cape York meteorite. When the American polar explorer Robert Peary shipped the largest piece of the meteorite to the American Museum of Natural History in New York City in 1897, it still weighed over 33 tons.

The name for iron in several ancient languages means "sky metal" or something similar. In distant antiquity, iron was regarded as a precious metal, suitable for royal ornaments.

The Iron Age

Beginning between 3000 BC to 2000 BC increasing numbers of smelted iron objects (distinguishable from meteoric iron by their lack of nickel) appear in Anatolia, Egypt and Mesopotamia (see Iron: History). The oldest known samples of iron that appear to have been smelted from iron oxides are small lumps found at copper-smelting sites on the Sinai Peninsula, dated to about 3000 BC.

In Anatolia, smelted iron was occasionally used for ornamental weapons: an iron-bladed dagger with a bronze hilt has been recovered from a Hattic tomb dating from 2500 BC. Also, the Egyptian ruler Tutankhamun died in 1323 BC and was buried with an iron dagger with a golden hilt. An Ancient Egyptian sword bearing the name of pharaoh Merneptah as well as a battle axe with an iron blade and gold-decorated bronze haft were both found in the excavation of Ugarit (see Ugarit). The early Hittites are known to have bartered iron for silver, at a rate of 40 times the iron's weight, with Assyria.

Iron did not, however, replace bronze as the chief metal used for weapons and tools for several centuries, despite some attempts. Then, between 1200 and 1000 BC, iron tools and weapons displaced bronze ones throughout the near east. This process appears to have begun in the Hittite Empire around 1300 BC, or in Cyprus and southern Greece, where iron artifacts dominate the archaeological record after 1050 BC. Mesopotamia was fully into the Iron Age by 900 BC, central Europe by 800 BC. Egypt, on the other hand, did not experience such a rapid transition from the bronze to iron ages: although Egyptian smiths did produce iron artifacts, bronze remained in widespread use there until after Egypt's conquest by Assyria in 663 BC.

Iron smelting at this time was based on the bloomery, a furnace where bellows were used to force air through a pile of iron ore and burning charcoal. The carbon monoxide produced by the charcoal reduced the iron oxides to metallic iron, but the bloomery was not hot enough to melt the iron. The result of this time-consuming and laborious process was wrought iron, a malleable but fairly soft alloy containing little carbon.

Wrought iron can be carburized into a mild steel by holding it in a charcoal fire for prolonged periods of time. The oldest quench-hardened steel artifact is a knife found on Cyprus at a site dated to 1100 BC. Around 500 BC, however, metalworkers in the southern state of Wu developed an iron smelting technology that would not be practiced in Europe until late medieval times. As a liquid, iron can be cast into molds, a method far less laborious than individually forging each piece of iron from a bloom.

Cast iron is rather brittle and unsuitable for striking implements. The artifacts recovered from this grave are variously made of wrought iron, cast iron, malleabilized cast iron, and quench-hardened steel, with only a few, probably ornamental, bronze weapons.

During the Han Dynasty (202 BC窶鄭D 220), Chinese ironworking achieved a scale and sophistication not reached in the West until the eighteenth century. (In Chinese, the process was called chao, literally, stir frying.)

Also during this time, Chinese metallurgists had found that wrought iron and cast iron could be melted together to yield an alloy of intermediate carbon content, that is, steel.

Steelmaking in India and Sri Lanka

Perhaps as early as 300 BC, although certainly by AD 200, high quality steel was being produced in southern India also by what Europeans would later call the crucible technique. forged or cast in the 4th century AD, and which has stood for many centuries next to the Qutab Minar in the Qutb complex in Delhi, is a testimony of the metallurgical skills of Indian artisans.

Steelmaking in the Middle East

By the 9th century, smiths in the Abbasid caliphate had developed techniques for forging wootz to produce steel blades of unusual flexibility and sharpness (Damascus steel).

Ironworking in medieval Europe

The middle ages in Europe saw the construction of progressively larger bloomeries. By the 8th century, smiths in northern Spain had developed a style that become known as a Catalan forge, a furnace about 1 meter (3 feet) tall, capable of smelting up to 150 kg (350 lb) of iron in each batch. In succeeding centuries, smiths in the Frankish empire and later the Holy Roman Empire scaled up this basic design, increasing the height of the flue to as tall as 5 meters (16 feet) and smelting as much as 350 kg (750 lb) of iron in each batch. To this end, waterwheels were employed to power the bellows and hammers.

Eventually, the scaling up of the bloomery reached a point where the furnace was hot enough to produce cast iron. Although the brittle cast iron may initially have been a nuisance to the smith, as it was too brittle to be forged, the spread of cannons to Europe in the 1300s provided an application for iron casting: cast iron cannonballs.

The oldest known blast furnace in Europe was constructed at Lapphyttan in Sweden, sometime between 1150 and 1350. Other early European blast furnaces were built throughout the Rhine valley: blast furnaces were in operation near Liティge (a city in modern-day Belgium) in the 1340s, and at Massevaux in France by 1409.

The first English blast furnace was not built until 1491, when Queenstock furnace was built at Buxted, followed by one commissioned Henry VII at Newbridge, in 1496 in a part of Sussex known as the Weald. In 1543, William Levett, an English rector who doubled as a Wealden ironmaster , and Peter Baude, a French craftsman in Henry VIII's employ, cast the Weald's first one-piece iron cannon. The superiority of English cannons over Spanish ones has been credited as one factor in England's 1588 defeat of the Spanish Armada.

In 1619, Jan Andries Moerbeck, a Dutch ironmaster, began importing Wealden iron ore for comparison to the ore available on the Continent.

Soon after that it was found that the best steel could only be produced by buying expensive テカrgrund (or oregrounds) iron from Sweden. This Swedish iron provided the main basis for English steelmaking until the 1850s

Benjamin Huntsman in the 1740s found a method of producing a more homogeneous steel. He made this discovery at Handsworth in England. Sheffield's Abbeydale Industrial Hamlet has preserved a waterwheel powered, scythe-making works dating from Huntsman's times. King, 'The cartel in oregrounds iron' Journal of Industrial History 6 (2003), 25-48.

Ironmaking in early modern Europe

From the 16th century to the 18th century, most iron was made by a two-stage process involving a blast furnace and finery forge, using charcoal as fuel. In 1709 Abraham Darby began smelting iron using coke, a refined coal product, in place of charcoal at his ironworks at Coalbrookdale in England. It was not until the 1750s, when Darby's son, also called Abraham, managed to start selling coke-smelted pig iron for the production of wrought iron in finery forges. In particular, the form of coal-fired puddling furnace developed by the British ironmaster Henry Cort in 1784 made it possible to convert cast iron into wrought iron in large batches (without charcoal), rendering the ancient finery forge obsolescent.

Industrial steelmaking

The problem of mass-producing steel was solved in 1855 by Henry Bessemer, with the introduction of the Bessemer converter at his steelworks in Sheffield, England. In the Bessemer process, molten pig iron from the blast furnace was charged into a large crucible, and then air was blown through the molten iron from below, igniting the dissolved carbon from the coke. After the carbon content in the melt had dropped to the desired level, the air draft was cut off: a typical Bessemer converter could convert a 25-ton batch of pig iron to steel in half an hour.

In 1867, the German-British engineer Sir William Siemens introduced an improved puddling furnace – The next year Pierre and Émile Martin, French ironmasters who had licensed Siemens' furnace design, developed a method for measuring the carbon content of molten iron. Reasons for this include its ability to recycle scrap metal in addition to fresh pig iron, its greater scalability (up to hundreds of tons per batch, compared to tens of tons for the Bessemer process), and the more precise quality control it permitted.

Initially, only ores low in phosphorus and sulfur could be used for quality steelmaking; This problem was solved in 1878 by Percy Carlyle Gilchrist and his cousin Sidney Gilchrist Thomas at the ironworks at Blaenavon in Wales. Their modified Bessemer process used a converter lined with limestone or dolomite, and additional lime was added to the molten metal as a Flux. This development expanded the range of iron ores that could be used to make steel, especially in France and Germany, where high-phosphorus ores abounded.

Finally, the basic oxygen process was introduced at the Voest-Alpine works in 1952; The top three steel-producing countries were China (349.4 mmt), Japan (112.5 mmt) and the United States (93.9 mmt) (see chart below).

Until these 19th century developments, steel was an expensive commodity and only used for a limited number of purposes where a particularly hard or flexible metal was needed, as in the cutting edges of tools and springs. Mild steel ultimately replaced wrought iron for almost all purposes, and wrought iron is not now (or is hardly now) made. Stainless steel was only developed on the eve of the First World War and only began to come into widespread use in the 1920s.

Types of steel

Alloy steels were known from antiquity, being nickel-rich iron from meteorites hot-worked into useful products.

Historic types

  • Damascus steel, which was famous in ancient times for its durability and ability to hold an edge, was created from a number of different materials (some only in traces), essentially a complicated alloy with iron as main component.
  • Blister steel - steel produced by the cementation process
  • Crucible steel - steel produced by Benjamin Huntsman's crucible technique
  • Styrian Steel, also called 'German steel' or 'Cullen steel' (being traded through Cologne) was made in Styria in Austria by fining cast iron from certain manganese-rich ores.
  • Shear steel was blister steel that was broken up, faggotted, heated and welded to produce a more homogeneous product

Contemporary steel

  • Carbon steel, composed simply of iron and carbon accounts for 90% of steel production.
  • HSLA steel (high strength, low alloy) have small additions (usually <2% by weight) of other elements, typically 1.5% manganese, to provide additional strength for a modest price increase.
  • Low alloy steel is alloyed with other elements, usually molybdenum, manganese, chromium, or nickel, in amounts of up to 10% by weight to improve the hardenability of thick sections.
  • Stainless steels and surgical stainless steels contain a minimum of 10% chromium, often combined with nickel, to resist corrosion (rust).
  • Tool steels are alloyed with large amounts of tungsten and cobalt or other elements to maximize solution hardening, allow precipitation hardening and improve temperature resistance.
  • Advanced High Strength Steels
    • Complex Phase Steel
    • Dual Phase Steel
    • TRIP steel
    • TWIP steel
    • Maraging steel
    • Eglin Steel
  • Ferrous superalloys
  • Hadfield steel (after Sir Robert Hadfield) or Manganese steel, this contains 12-14% manganese which when abraded forms an incredibly hard skin which resists wearing. Some examples are tank tracks, bulldozer blade edges and cutting blades on the jaws of life.

Though not an alloy, there exists also galvanized steel, which is steel that has gone through the chemical process of being hot-dipped or electroplated in zinc for protection against rust. The relatively soft core helps in ductility of the steel while treated skin has good weldability to suit to the construction requirements.

Production methods

Historical methods

  • bloomery
  • pattern welding
  • catalan forge
  • wootz steel (crucible technique): developed in India, used in the Middle East where it was known as Damascus steel.
  • Cementation process used to convert bars of wrought iron into blister steel.
  • crucible technique, similar to the wootz steel, independently redeveloped in Sheffield by Benjamin Huntsman in c.1740, and Pavel Anosov in Russia in 1837.
  • Puddling

Modern methods

  • Electric arc furnace a form of secondary steelmaking from scrap, though the process can also use direct-reduced iron
  • Production of pig iron using blast furnace
  • Converters (steel from pig iron):
  1. Bessemer process, the first large-scale steel production process for mild steel.
  2. The Siemens-Martin process, using an Open hearth furnace
  3. Basic oxygen steelmaking

Uses of steel

Historically

Steel was expensive and was only used where nothing else would do, particularly for the cutting edge of knives, razors, swords, and other tools where a hard sharp edged was needed. It continues to be used in many situations, though the new availabilty of plastics during the 20th century has meant that it has ceased to be used for some.

Long steel

  • Wires
  • Rail tracks
  • As girders in building modern tall buildings, bridges

Flat carbon steel

  • For the inside and outside body of cars, trains
  • Major appliances

Stainless steel

  • Cutlery
  • Rulers

See also

  • Structural steel
  • Rolling (metalworking)
  • Cold rolling
  • Hot rolling
  • Steel producers
  • Steel mill
  • Rolling mill
  • Foundry
  • Tinplate
  • Global steel industry trends

Additional topics

Company HistoryMetal Manufacturing & Fabricating

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