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Crucible steel is steel made by melting pig iron (cast iron), iron, and sometimes steel, often along with sand, glass, ashes, and other fluxes, in a crucible. Crucible steel was first developed in the middle of the 1st millennium BCE in Southern India and Sri Lanka using the wootz process. [1] [2] [3] [4]
In ancient times, it wasn't possible to produce very high temperatures with charcoal or coal fires, which was required to melt iron or steel. However, pig iron, having a higher carbon content and thus a lower melting point, could be melted, and by soaking wrought iron or steel in the liquid pig-iron for a long time, the carbon content of the pig iron could be reduced as it slowly diffused into the iron, turning both into steel. Crucible steel of this type was produced in South and Central Asia during the medieval era.
This generally produced a very hard steel, but also a composite steel that was inhomogeneous, consisting of a very high-carbon steel (formerly the pig-iron) and a lower-carbon steel (formerly the wrought iron). This often resulted in an intricate pattern when the steel was forged, filed or polished, with possibly the most well-known examples coming from the wootz steel used in Damascus swords. The steel was often much higher in carbon content (typically ranging in the area of 1.5 to 2.0%) and in quality (lacking impurities) in comparison with other methods of steel production of the time because of the use of fluxes. The steel was usually worked very little and at relatively low temperatures to avoid any decarburization, hot short crumbling, or excess diffusion of carbon.
With a carbon content close to that of cast iron, it usually required no heat treatment after shaping other than air cooling to achieve the correct hardness, relying on composition alone. The higher-carbon steel provided a very hard edge, but the lower-carbon steel helped to increase the toughness, helping to decrease the chance of chipping, cracking, or breaking. [5]
In Europe, crucible steel was developed by Benjamin Huntsman in England in the 18th century. Huntsman used coke rather than coal or charcoal, achieving temperatures high enough to melt steel and dissolve iron. Huntsman's process differed from some of the wootz processes in that it used a longer time to melt the steel and to cool it down and thus allowed more time for the diffusion of carbon. [6] Huntsman's process used iron and steel as raw materials, in the form of blister steel, rather than direct conversion from cast iron as in puddling or the later Bessemer process.
The ability to fully melt the steel removed any inhomogeneities in the steel, allowing the carbon to dissolve evenly into the liquid steel and negating the prior need for extensive blacksmithing in an attempt to achieve the same result. Similarly, it allowed steel to be cast by pouring into molds. The use of fluxes allowed nearly complete extraction of impurities from the liquid, which could then simply float to the top for removal. This produced the first steel of modern quality, providing a means of efficiently changing excess wrought iron into useful steel. Huntsman's process greatly increased the European output of quality steel suitable for use in items like knives, tools, and machinery, helping to pave the way for the Industrial Revolution.
Iron alloys are most broadly divided by their carbon content: cast iron has 2–4% carbon impurities; wrought iron oxidizes away most of its carbon, to less than 0.1%. The much more valuable steel has a delicately intermediate carbon fraction, and its material properties range according to the carbon percentage: high carbon steel is stronger but more brittle than low carbon steel. Crucible steel sequesters the raw input materials from the heat source, allowing precise control of carburization (raising) or decarburization (lowering carbon content). Fluxes, such as limestone, could be added to the crucible to remove or promote sulfur, silicon, and other impurities, further altering its material qualities.
Various methods were used to produce crucible steel. According to Islamic texts such as al-Tarsusi and Abu Rayhan Biruni, three methods are described for indirect production of steel. [7] The medieval Islamic historian Abu Rayhan Biruni (c. 973–1050) provides the earliest reference of the production of Damascus steel. [8] The first, and the most common, traditional method is solid state carburization of wrought iron. This is a diffusion process in which wrought iron is packed in crucibles or a hearth with charcoal, then heated to promote diffusion of carbon into the iron to produce steel. [9] Carburization is the basis for the wootz process of steel. The second method is the decarburization of cast iron by removing carbon from the cast iron. [8] The third method uses wrought iron and cast iron. In this process, wrought iron and cast iron may be heated together in a crucible to produce steel by fusion. [9] In regard to this method Abu Rayhan Biruni states: "this was the method used in Hearth". It is proposed that the Indian method refers to Wootz carburization method; [8] i.e., the Mysore or Tamil processes. [10]
Variations of co-fusion process have been found primarily in Persia and Central Asia but have also been found in Hyderabad, India [11] called Deccani or Hyderabad process. [10] For the carbon, a variety of organic materials are specified by the contemporary Islamic authorities, including pomegranate rinds, acorns, fruit skins like orange peel, leaves as well as the white of egg and shells. Slivers of wood are mentioned in some of the Indian sources, but significantly none of the sources mention charcoal. [12]
Crucible steel is generally attributed to production centres in India and Sri Lanka where it was produced using the so-called "wootz" process, and it is assumed that its appearance in other locations was due to long-distance trade. [13] Only recently it has become apparent that places in Central Asia like Merv in Turkmenistan and Akhsiket in Uzbekistan were important centres of production of crucible steel. [14] The Central Asian finds are all from excavations and date from the 8th to 12th centuries CE, while the Indian/Sri Lankan material is as early as 300 BCE. India's iron ore had trace vanadium and other alloying elements leading to increased hardenability in Indian crucible steel which was famous throughout the middle east for its ability to retain an edge.
While crucible steel is more attributed to the Middle East in early times, pattern welded swords, incorporating high-carbon, and likely crucible steel, have been discovered in Europe, from the 3rd century CE, [15] [16] particularly in Scandinavia. Swords bearing the brand name Ulfberht, and dating to a 200-year period from the 9th century to the early 11th century, are prime examples of the technique. It is speculated by many[ who? ] that the process of making these blades originated in the Middle East and subsequently had been traded during the Volga Trade Route days. [17]
In the first centuries of the Islamic period, some scientific studies on swords and steel appeared. The best known of these are by Jabir ibn Hayyan 8th century, al-Kindi 9th century, Al-Biruni in the early 11th century, al-Tarsusi in the late 12th century, and Fakhr-i-Mudabbir 13th century. Any of these contains far more information about Indian and damascene steels than appears in the entire surviving literature of classical Greece and Rome. [18]
There are many ethnographic accounts of Indian crucible steel production; however, scientific investigations of the remains of crucible steel production have only been published for four regions: three in India and one in Sri Lanka. [19] Indian/Sri Lankan crucible steel is commonly referred to as wootz, which is generally agreed to be an English corruption of the word ukko (in the Canarese language) or hookoo (in the Telugu language). [20] [21]
European accounts from the 17th century onwards have referred to the repute and manufacture of "wootz", a traditional crucible steel made specially in parts of southern India in the former provinces of Golconda, Mysore and Salem. As yet the scale of excavations and surface surveys is too limited to link the literary accounts to archaeometallurgical evidence. [22]
The proven sites of crucible steel production in south India, e.g. at Konasamudram and Gatihosahalli, date from at least the late medieval period, 16th century. [23] One of the earliest known potential sites, which shows some promising preliminary evidence that may be linked to ferrous crucible processes in Kodumanal, near Coimbatore in Tamil Nadu. [24] The site is dated between the third century BCE and the third century CE. [25] By the seventeenth century the main centre of crucible steel production seems to have been in Hyderabad. The process was apparently quite different from that recorded elsewhere. [26] Wootz from Hyderabad or the Decanni process for making watered blades involved a co-fusion of two different kinds of iron: one was low in carbon and the other was a high-carbon steel or cast iron. [27] Wootz steel was widely exported and traded throughout ancient Europe, China, the Arab world, and became particularly famous in the Middle East, where it became known as Damascus steel. [28] [29]
Recent archaeological investigations have suggested that Sri Lanka also supported innovative technologies for iron and steel production in antiquity. [30] The Sri Lankan system of crucible steel making was partially independent of the various Indian and Middle Eastern systems. [31] Their method was something similar to the method of carburization of wrought iron. [30] The earliest confirmed crucible steel site is located in the Knuckles range in the northern area of the Central Highlands of Sri Lanka dated to 6th–10th centuries CE. [32] In the twelfth century the land of Serendib (Sri Lanka) seems to have been the main supplier of crucible steel, but over the centuries production slipped back, and by the nineteenth century just a small industry survived in the Balangoda district of the central southern highlands. [33]
A series of excavations at Samanalawewa indicated the unexpected and previously unknown technology of west-facing smelting sites, which are different types of steel production. [30] [34] These furnaces were used for direct smelting to steel. [35] These are named "west facing" because they were located on the western sides of hilltops to use the prevailing wind in the smelting process. [36] Sri Lankan furnace steels were known and traded between the 9th and 11th centuries and earlier, but apparently not later. [37] These sites were dated to the 7th–11th centuries. The coincidence of this dating with the 9th century Islamic reference to Sarandib [36] is of great importance. The crucible process existed in India at the same time that the west- facing technology was operating in Sri Lanka. [38] Excavations of the Yodhawewa (near Mannar) site (in 2018) have uncovered a lower half of a bottom spherical furnace and crucible fragments used to make crucible steel in Sri Lanka during the 7th-8th centuries AD. The crucible fragments uncovered at the site were similar to the elongated tube-shaped crucibles of Samanalawewa. [2]
Central Asia has a rich history of crucible steel production, beginning during the late 1st millennium CE. [39] From the sites in modern Uzbekistan and Merv in Turkmenistan, there is good archaeological evidence for the large scale production of crucible steel. [40] They all belong in broad terms to the same early medieval period between the late 8th or early 9th and the late 12th century CE, [41] contemporary with the early crusades. [40]
The two most prominent crucible steel sites in eastern Uzbekistan carrying the Ferghana Process are Akhsiket and Pap in the Ferghana Valley, whose position within the Great Silk Road has been historically and archaeologically proved. [42] The material evidence consists of large number of archaeological finds relating to steel making from 9th–12th centuries CE in the form of hundreds of thousands of fragments of crucibles, often with massive slag cakes. [39] Archaeological work at Akhsiket, has identified that the crucible steel process was of the carburization of iron metal. [12] This process appears to be typical of and restricted to the Ferghana Valley in eastern Uzbekistan, and it is therefore called the Ferghana Process. [43] This process lasted in that region for roughly four centuries..
Evidence of the production of crucible steel have been found in Merv, Turkmenistan, a major city on the 'Silk Road'. The Islamic scholar al-Kindi (801–866 CE) mentions that during the ninth century CE the region of Khorasan, the area to which the cities Nishapur, Merv, Herat and Balkh belong, was a steel manufacturing centre. [44] Evidence from a metallurgical workshop at Merv, dated to the ninth- early tenth century CE, provides an illustration of the co-fusion method of steel production in crucibles, about 1000 years earlier than the distinctly different wootz process. [45] The crucible steel process at Merv might be seen as technologically related to what Bronson (1986, 43) calls Hyderabad process, a variation of the wootz process, after the location of the process documented by Voysey in the 1820s. [46]
The production of crucible steel in China began around the first century BC, or possibly earlier. The Chinese developed a method of producing pig iron around 1200 BC, which they used to make cast iron. By the first century BC, they had developed puddling to produce mild steel and a process of rapidly decarburizing molten cast-iron to make wrought iron by stirring it atop beds of saltpeter (called the Heaton process, it was independently discovered by John Heaton in the 1860s). Around this time, the Chinese began producing crucible steel to convert excess quantities of cast iron and wrought iron into steel suitable for swords and weapons. [47] [48]
In 1064, Shen Kuo, in his book Dream Pool Essays , gave the earliest written description of the patterns in the steel, the methods of sword production, and some of the reasoning behind it:
Ancient people use chi kang, (combined steel), for the edge, and jou thieh (soft iron) for the back, otherwise it would often break. Too strong a weapon will cut and destroy its own edge; that is why it is advisable to use nothing but combined steel. As for the yu-chhang (fish intestines) effect, it is what is now called the 'snake-coiling' steel sword, or alternatively, the 'pine tree design'. If you cook a fish fully and remove its bones, the shape of its guts will be seen to be like the lines on a 'snake-coiling sword'. [49]
The first European references to crucible steel seem to be no earlier than the Post Medieval period. [50] European experiments with “Damascus” steels go back to at least the sixteenth century, but it was not until the 1790s that laboratory researchers began to work with steels that were specifically known to be Indian/wootz. [51] At this time, Europeans knew of India's ability to make crucible steel from reports brought back by travellers who had observed the process at several places in southern India.
From the mid-17th century onwards, European travellers to the Indian subcontinent wrote numerous vivid eyewitness accounts of the production of steel there. These include accounts by Jean-Baptiste Tavernier in 1679, Francis Buchanan in 1807, and H.W. Voysey in 1832. [52] The 18th, 19th and early 20th century saw a heady period of European interest in trying to understand the nature and properties of wootz steel. Indian wootz engaged the attention of some of the best-known scientists. [53] One was Michael Faraday who was fascinated by wootz steel. It was probably the investigations of George Pearson, reported at the Royal Society in 1795, which had the most far-reaching impact in terms of kindling interest in wootz amongst European scientists. [54] He was the first of these scientists to publish his results and, incidentally, the first to use the word "wootz" in print. [55]
Another investigator, David Mushet, was able to infer that wootz was made by fusion. [56] David Mushet patented his process in 1800. [57] He made his report in 1805. [55] As it happens, however, the first successful European process had been developed by Benjamin Huntsman some 50 years previously in the 1740s. [58]
Benjamin Huntsman was a clockmaker in search of a better steel for clock springs. In Handsworth near Sheffield, he began producing steel in 1740 after years of experimenting in secret. Huntsman's system used a coke-fired furnace capable of reaching 1,600 °C, into which up to twelve clay crucibles, each capable of holding about 15 kg of iron, were placed. When the crucibles or "pots" were white-hot, they were charged with lumps of blister steel, an alloy of iron and carbon produced by the cementation process, and a flux to help remove impurities. The pots were removed after about 3 hours in the furnace, impurities in the form of slag skimmed off, and the molten steel poured into moulds to end up as cast ingots. [59] [60] Complete melting of the steel produced a highly uniform crystal structure upon cooling, which gave the metal increased tensile strength and hardness in comparison with other steels being made at the time.
Before the introduction of Huntsman's technique, Sheffield produced about 200 tonnes of steel per year from Swedish wrought iron (see Oregrounds iron). The introduction of Huntsman's technique changed this radically: one hundred years later the amount had risen to over 80,000 tonnes per year, or almost half of Europe's total production. Sheffield developed from a small township into one of Europe's leading industrial cities.
The steel was produced in specialised workshops called 'crucible furnaces', which consisted of a workshop at ground level and a subterranean cellar. The furnace buildings varied in size and architectural style, growing in size towards the latter part of the 19th century as technological developments enabled multiple pots to be "fired" at once, using gas as a heating fuel. Each workshop had a series of standard features, such as rows of melting holes, teaming pits,[ clarification needed ] roof vents, rows of shelving for the crucible pots and annealing furnaces to prepare each pot before firing. Ancillary rooms for weighing each charge and for the manufacture of the clay crucibles were either attached to the workshop, or located within the cellar complex. The steel, originally intended for making clock springs, was later used in other applications such as scissors, axes and swords.
Sheffield's Abbeydale Industrial Hamlet operates for the public a scythe-making works, which dates from Huntsman's times and is powered by a water wheel, using crucible steel made at the site.
Previous to Huntsman, the most common method of producing steel was the manufacture of shear steel. In this method, blister steel produced by cementation was used, which consisted of a core of wrought iron surrounded by a shell of very high-carbon steel, typically ranging from 1.5 to 2.0% carbon. To help homogenize the steel, it was pounded into flat plates, which were stacked and forge welded together. This produced steel with alternating layers of steel and iron. The resulting billet could then be hammered flat, cut into plates, which were stacked and welded again, thinning and compounding the layers, and evening out the carbon more as it slowly diffused out of the high-carbon steel into the lower-carbon iron. However, the more the steel was heated and worked, the more it tended to decarburize, and this outward diffusion occurs much faster than the inward diffusion between layers. Thus, further attempts to homogenize the steel resulted in a carbon content too low for use in items like springs, cutlery, swords, or tools. Therefore, steel intended for use in such items, especially tools, was still being made primarily by the slow and arduous bloomery process in very small amounts and at high cost, which, albeit better, had to be manually separated from the wrought iron and was still impossible to fully homogenize in the solid state.
Huntsman's process was the first to produce a fully homogeneous steel. Unlike previous methods of steel production, the Huntsman process was the first to fully melt the steel, allowing the full diffusion of carbon throughout the liquid. With the use of fluxes it also allowed the removal of most impurities, producing the first steel of modern quality. Due to carbon's high melting point (nearly triple that of steel) and its tendency to oxidize (burn) at high temperatures, it cannot usually be added directly to molten steel. However, by adding wrought iron or pig iron, allowing it to dissolve into the liquid, the carbon content could be carefully regulated (in a way similar to Asian crucible-steels but without the stark inhomogeneities indicative of those steels). Another benefit was that it allowed other elements to be alloyed with the steel. Huntsman was one of the first to begin experimenting with the addition of alloying agents like manganese to help remove impurities such as oxygen from the steel. His process was later used by many others, such as Robert Hadfield and Robert Forester Mushet, to produce the first alloy steels like mangalloy, high-speed steel, and stainless steel.
Due to variations in the carbon content of the blister steel, the carbon steel produced could vary in carbon content between crucibles by as much as 0.18%, but on average produced a eutectoid steel containing ~ 0.79% carbon. Due to the quality and high hardenability of the steel, it was quickly adopted for the manufacture of tool steel, machine tools, cutlery, and many other items. Because no oxygen was blown through the steel, it exceeded Bessemer steel in both quality and hardenability, so Huntsman's process was used for manufacturing tool steel until better methods, utilizing an electric arc, were developed in the early 20th century. [61] [62]
In another method, developed in the United States in the 1880s, iron and carbon were melted together directly to produce crucible steel. [63] Throughout the 19th century and into the 1920s a large amount of crucible steel was directed into the production of cutting tools, where it was called tool steel.
The crucible process continued to be used for specialty steels, but is today obsolete. Similar quality steels are now made with an electric arc furnace. Some uses of tool steel were displaced, first by high-speed steel [63] and later by materials such as tungsten carbide.
Another form of crucible steel was developed in 1837 by the Russian engineer Pavel Anosov. His technique relied less on the heating and cooling, and more on the quenching process of rapidly cooling the molten steel when the right crystal structure had formed within. He called his steel bulat; its secret died with him. In the United States crucible steel was pioneered by William Metcalf.
An alloy is a mixture of chemical elements of which in most cases at least one is a metallic element, although it is also sometimes used for mixtures of elements; herein only metallic alloys are described. Most alloys are metallic and show good electrical conductivity, ductility, opacity, and luster, and may have properties that differ from those of the pure elements such as increased strength or hardness. In some cases, an alloy may reduce the overall cost of the material while preserving important properties. In other cases, the mixture imparts synergistic properties such as corrosion resistance or mechanical strength.
Brass is an alloy of copper and zinc, in proportions which can be varied to achieve different colours and mechanical, electrical, acoustic and chemical properties, but copper typically has the larger proportion, generally 66% copper and 34% zinc. In use since prehistoric times, it is a substitutional alloy: atoms of the two constituents may replace each other within the same crystal structure.
Damascus steel refers to the high carbon crucible steel of the blades of historical swords forged using the wootz process in the Near East, characterized by distinctive patterns of banding and mottling reminiscent of flowing water, sometimes in a "ladder" or "rose" pattern. "Damascus steel" developed a high reputation for being tough, resistant to shattering, and capable of being honed to a sharp, resilient edge.
Pattern welding is the practice in sword and knife making of forming a blade of several metal pieces of differing composition that are forge-welded together and twisted and manipulated to form a pattern. Often mistakenly called Damascus steel, blades forged in this manner often display bands of slightly different patterning along their entire length. These bands can be highlighted for cosmetic purposes by proper polishing or acid etching. Pattern welding was an outgrowth of laminated or piled steel, a similar technique used to combine steels of different carbon contents, providing a desired mix of hardness and toughness. Although modern steelmaking processes negate the need to blend different steels, pattern welded steel is still used by custom knifemakers for the cosmetic effects it produces.
Steel is an alloy of iron and carbon with improved strength and fracture resistance compared to other forms of iron. Because of its high tensile strength and low cost, steel is one of the most commonly manufactured materials in the world. Steel is used in buildings, as concrete reinforcing rods, in bridges, infrastructure, tools, ships, trains, cars, bicycles, machines, electrical appliances, furniture, and weapons.
The Bessemer process was the first inexpensive industrial process for the mass production of steel from molten pig iron before the development of the open hearth furnace. The key principle is removal of impurities from the iron by oxidation with air being blown through the molten iron. The oxidation also raises the temperature of the iron mass and keeps it molten.
Wrought iron is an iron alloy with a very low carbon content in contrast to that of cast iron. It is a semi-fused mass of iron with fibrous slag inclusions, which give it a wood-like "grain" that is visible when it is etched, rusted, or bent to failure. Wrought iron is tough, malleable, ductile, corrosion resistant, and easily forge welded, but is more difficult to weld electrically.
A crucible is a container in which metals or other substances may be melted or subjected to very high temperatures. Although crucibles have historically tended to be made out of clay, they can be made from any material that withstands temperatures high enough to melt or otherwise alter its contents.
Wootz steel is a crucible steel characterized by a pattern of bands and high carbon content. These bands are formed by sheets of microscopic carbides within a tempered martensite or pearlite matrix in higher-carbon steel, or by ferrite and pearlite banding in lower-carbon steels. It was a pioneering steel alloy developed in southern India in the mid-1st millennium BC and exported globally.
The cementation process is an obsolete technology 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 the UK is the cementation furnace in Doncaster Street, Sheffield.
Carburizing, or carburising, is a heat treatment process in which iron or steel absorbs carbon while the metal is heated in the presence of a carbon-bearing material, such as charcoal or carbon monoxide. The intent is to make the metal harder and more wear resistant. Depending on the amount of time and temperature, the affected area can vary in carbon content. Longer carburizing times and higher temperatures typically increase the depth of carbon diffusion. When the iron or steel is cooled rapidly by quenching, the higher carbon content on the outer surface becomes hard due to the transformation from austenite to martensite, while the core remains soft and tough as a ferritic and/or pearlite microstructure.
A bloomery is a type of metallurgical furnace once used widely for smelting iron from its oxides. The bloomery was the earliest form of smelter capable of smelting iron. Bloomeries produce a porous mass of iron and slag called a bloom. The mix of slag and iron in the bloom, termed sponge iron, is usually consolidated and further forged into wrought iron. Blast furnaces, which produce pig iron, have largely superseded bloomeries.
Case-hardening or carburization is the process of introducing carbon to the surface of a low carbon iron or much more commonly low carbon steel object in order to enable the surface to be hardened.
The history of metallurgy in the Indian subcontinent began prior to the 3rd millennium BCE. Metals and related concepts were mentioned in various early Vedic age texts. The Rigveda already uses the Sanskrit term ayas. The Indian cultural and commercial contacts with the Near East and the Greco-Roman world enabled an exchange of metallurgic sciences. The advent of the Mughals further improved the established tradition of metallurgy and metal working in India. During the period of British rule in India, the metalworking industry in India stagnated due to various colonial policies, though efforts by industrialists led to the industry's revival during the 19th century.
Bladesmithing is the art of making knives, swords, daggers and other blades using a forge, hammer, anvil, and other smithing tools. Bladesmiths employ a variety of metalworking techniques similar to those used by blacksmiths, as well as woodworking for knife and sword handles, and often leatherworking for sheaths. Bladesmithing is an art that is thousands of years old and found in cultures as diverse as China, Japan, India, Germany, Korea, the Middle East, Spain and the British Isles. As with any art shrouded in history, there are myths and misconceptions about the process. While traditionally bladesmithing referred to the manufacture of any blade by any means, the majority of contemporary craftsmen referred to as bladesmiths are those who primarily manufacture blades by means of using a forge to shape the blade as opposed to knifemakers who form blades by use of the stock removal method, although there is some overlap between both crafts.
A Walloon forge is a type of finery forge that decarbonizes pig iron into wrought iron.
Ferrous metallurgy is the metallurgy of iron and its alloys. The earliest surviving prehistoric iron artifacts, from the 4th millennium BC in Egypt, were made from meteoritic iron-nickel. It is not known when or where the smelting of iron from ores began, but by the end of the 2nd millennium BC iron was being produced from iron ores in the region from Greece to India, The use of wrought iron was known by the 1st millennium BC, and its spread defined the Iron Age. During the medieval period, smiths in Europe found a way of producing wrought iron from cast iron, in this context known as pig iron, using finery forges. All these processes required charcoal as fuel.
Toledo steel, historically known for being unusually hard, is from Toledo, Spain, which has been a traditional sword-making, metal-working center since about the Roman period, and came to the attention of Rome when used by Hannibal in the Punic Wars. It soon became a standard source of weaponry for Roman legions.
Early Japanese iron-working techniques are known primarily from archaeological evidence dating to the Asuka period. Iron was first brought to Japan during the earlier Yayoi period. Iron artifacts of the period include farm implements, arrowheads, and rarely a knife blade. An ironworking industry likely evolved during the late Yayoi or the Kofun period, when iron weapons and armor became more common. However, the best archaeological evidence for early iron-working techniques in Japan dates to the Asuka period, after Buddhism had been introduced to the imperial court of the Yamato state.
The Iron and Steel industry in India is among the most important industries within the country. India surpassed Japan as the second largest steel producer in January 2019. As per worldsteel, India's crude steel production in 2018 was at 106.5 million tonnes (MT), 4.9% increase from 101.5 MT in 2017, which means that India overtook Japan as the world's second largest steel production country. Japan produced 104.3 MT in year 2018, decrease of 0.3% compared to year 2017.