The growing global population and the present living styles are telling upon the world’s ecosystems. The ensuing high CO2 emissions and waste disposal problems pose unparalleled threats to the present civilization. To a great extent, these challenges are now being solved by making use of steel as the infrastructure to meet the needs of the world. It builds towns and cities in harmony with the climate, and minimizes the impacts of natural disasters. The recyclable nature of steel and its byproducts is a boon, because, it is this primary material that integrates the global economy to propel sustainable development. This blessed steel becomes carbon steel, when carbon is added to steel. Steel and carbon steel are used in the production of various types of commercial and consumer applications. The difference between them depends upon the added components, to meet the desired objectives.
Steel
Humans began using iron, sometime after 2000 BCE, marking the Iron Age in Central Asia, by replacing bronze for making weapons and tools. Iron continued its supremacy for the next three thousand years in Europe, Asia, and Africa, but gave way to steel when Henry Bessemer, invented it in the mid 1850s.
Steel is iron based, and contains Carbon, Silicon, and Manganese. It is made through selective oxidation of impurities in Hot metal, Scrap or DRI. Steel has many sub-divisions considering the qualities and characteristics of the type, and such properties include strength, ductility, hardness, cost etc. A few of these types like nickel are not magnetic at all. In a generic sense, steel is classified in relation to its carbon content. It is non corrosive, less malleable, and hard. In order to enhance its properties steel is alloyed with chromium, nickel, molybdenum and other elements. Because of strength, hardness and elasticity, chromium steel is used in the construction of automobiles and airplane parts. The largest industry in the world is steel, which amounts to 1.3 billion tons, a year.
Carbon steel
According to Merriam-Webster dictionary, “Steel is commercial iron that contains carbon in any amount up to about 1.7 percent as an essential alloying constituent, is malleable when under suitable conditions, and is distinguished from cast iron by its malleability and lower carbon content.” Carbon steel is occasionally called ‘plain carbon steel’. The American Iron and Steel Institute distinguish carbon steel as having less than 2 % carbon without any other noticeable alloying element. The major share of the steel production accounts to carbon steel.
When the carbon content in the steel is increased, it will reduce the melting point of the steel and becomes harder and stronger, but at the same time it will tend to be less ductile and malleable. The steel will bend more allowing shaping, when its carbon content is reduced. That means it is carbon that adds strength to the steel, while leaving away the elasticity. Carbon steel products, like pans and pots that are used for cooking, get hotter evenly than other steels. Usually, carbon steel has a lusterless finish.
Mild steel is a form of carbon steel and it contains .05 – .29% carbon, while the medium type has .30 – .59%. There is .60 – .99% carbon in high carbon steel and 1.00 – 2.00% carbon in ultra carbon steel. Steel becomes carbon steel, provided it has carbon up to 2.1%. If the carbon percentage in steel is more than this, such steel is considered cast iron.
Carbon steel is stiff and exhibits ferromagnetism. That’s why they are extensively applied in automobiles and electrical appliances. It shows poor rust resistance, and therefore, they are not used in corrosive environment without applying some protective coating.