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The Origins of Steel
Steel is one of the most widely used metals in the world, and it is also one of the most common. We use steel in a variety of different ways from large scale industrial projects to small household items. Steel is a hugely durable metal and can be used in the building of trains, ships, bridges and railways - anything that needs to be long lasting and strong. You can also find steel in your home in the washing machine, the fridge, fixtures and fittings and in nails and screws. You may not have realised it but steel is all over the place. As well as being a strong metal steel is also able to withstand some tension and is good at holding a sharp edge. It is also particularly appropriate for use in sterile environments and is often used in surgical equipment. Every year 1.3 billion tons of steel are produced, usually with a blast furnace, and used in many different industries. The fact that stainless steel is often used to give a modern finish may suggest that it is only a fairly recent invention, The reality, however, is that though the process of steel production was improved in the past few centuries its history stretches back thousands of years.
The 'Iron Age'
Steel is made as an alloy from iron and carbon, which are both prevalent elements. Humans have been using iron and making things out of it for thousands of years. Proper production of iron metal began roughly around 2000 BC, before this the most commonly used hard material was bronze, an alloy made mostly out of copper. Use of bronze was so widespread that the period was later named the ‘Bronze Age’. Bronze fell out of use as people began to realise that iron, as a harder material, was more useful. Iron could also hold a sharp edge better than bronze, making it a good choice for weapons and implements. Unsurprisingly the use of iron caught on and the period was later dubbed the ‘Iron Age’.
Depending on how much carbon iron contained it could have different properties and therefore different uses. Iron with a small amount of carbon in it (roughly 0.02%) is a more malleable form of iron but it has less strength. This kind of iron is known as ‘wrought iron’. Iron that has much more carbon in it (between 3 and 4.5%) is stronger but less malleable - almost brittle. This type of iron is called ‘cast iron’. Steel, on the other hand, is something of a compromise between the two. Containing between 0.2 and 1.5% carbon, it stronger than wrought iron but more malleable than cast iron.
The process of making steel was refined and developed only a few centuries ago which gives the impression that it is a modern creation. The efficiency of the process was improved in the 17th century and then later made less expensive in the 19th century. Though these were important developments in the production of steel and helped to see in widespread usage through mass production, it was not the first time that steel had been created. You may think that creating steel needs advanced or modern technology, but in fact steel was being produced over a thousand years ago with much less sophisticated technology. Some of the earliest evidence of steel-working was found in Anatolia and dated as being 4,000 years old. Even the 17th century method of creating steel in a blast furnace has early predecessors. Steel has been found in East Africa that has been dated to 1400 BC and was likely to have been made in an early form of blast furnace by the Haya people.
Wootz & Damascus Steel
The most well-known types of early steel are Damascus steel and wootz steel and there is a certain air of mystery that surrounds both of them. Wootz steel dates to around 300 BC and was produced in Sri Lanka and India. This type of steel was created through the use of a wind furnace - a furnace that made use of the power of the monsoon winds. Damascus steel was something of a follow-on from Wootz steel. It is believed that Damascus steel was produced from ingots of Wootz steel that were brought to the Middle East via traders from India. It was said that Damascus steel had a number of superior properties and myths began that a sword made from Damascus steel could slice through a rifle barrel because it was so strong and sharp. Though this myth is unlikely to be true there is still an air of mystery surrounding early forms of steel. The reason for this is because the original technique used to produce both Damascus and Wootz steel have been lost to history. The techniques were lost around the end of the 17th and the beginning of the 18th century. Many experimental archaeologists and historians have attempted to recreate the methods that may have been used but have so far had no luck.
Though Wootz and Damascus steel are arguably the best known types of steel, at least among metallurgists and historians, there were many different types of early steel and methods for making it. The Romans made steel known as ‘Noric steel’ which was notable for its strength. The 4th and 3rd centuries BC saw steel production in the Iberian Peninsula and in China. The Chinese produced ‘quench hardened steel’ at this time but by the 1st century AD had developed ‘carbon-intermediate steel’ through a method that melted wrought iron with cast iron. By the 17th century steel production had transformed into something akin to today’s process, smelting iron ore into pig iron in a blast furnace. The 19th century changed the process again and made it easier to mass-produce through the use of the Bessemer process. Today ‘stainless steel’ may almost be synonymous with ‘modern’ but the process of making steel actually has its roots in very early history.
Useful & Related Links
- eHow.com: Properties & Uses of Steel
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- About.com: Steel History
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- How is Stainless Steel Made?
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- HowStuffWorks: Creating Steel
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