Steel is an alloy that consists mostly of iron, with a small amount of carbon. Carbon is a chemical element that is essential for steel production, as it binds iron molecules together, giving the steel its strength. Steel with a large amount of carbon is harder and stronger than steel with a lower amount of carbon, so by adjusting the amount of carbon present, different types of steel can be produced.
In alloy steel production, the amount of carbon present is usually between 0.15% and 2.0%, but even tiny adjustments to the percentage can make a big difference in the properties of the steel. Carbon can also affect the machinability and hardness of the steel, as well as the strength at high temperatures.
When the molten steel is first produced, it can contain a high percentage of carbon (up to 4%). After production, however, the steel needs to be treated so that the carbon content can be lowered to meet the required specifications. This process is known as decarburizing or de-oxidation, and is done by adding nitrogen or hydrogen to the steel, which binds with the oxygen in the steel and reduces its carbon content.
The most important factor to consider when deciding how much carbon to add to the steel is the specific application for which the steel is intended. For example, for structural or bridge components, steel with a higher carbon content (eg. 0.7%) would be used, as it is stronger than steel with a lower carbon content. However, for components that are intended to be welded or machined, steel with a lower carbon content (eg. 0.1%) would be used , as it would be easier to manipulate.
The amount of carbon present in the steel affects its properties in other ways. For example, when carbon is present, steel becomes more malleable and can be shaped into objects more easily. Carbon also allows heat to be conducted more quickly through the steel, which can be useful, depending on the intended application.
In short, carbon is an essential element in steel production, as it binds together iron molecules and allows them to be shaped into strong and durable structures. The amount of carbon present in steel affects its strength, malleability, and heat conductivity, and so should be carefully chosen based on the intended application of the steel. By understanding the role of carbon in steel production and choosing the right percentage for the job, steel products of all shapes and sizes can be successfully produced.
