decarburisation

Decarburisation is a process used to remove carbon, particularly in the form of iron carbides, from the surface of steel or other iron-based alloys. This is typically done to improve the properties of the material, such as its hardness, ductility, or resistance to corrosion. Decarburisation can be performed through various means, including heat treatment, mechanical grinding, or chemical processing.

During the decarburisation process, the carbon content in the surface layer of the steel is reduced, resulting in a hardened layer (known as the "case") on the outer surface. This case can provide enhanced resistance to wear and corrosion. However, if the decarburisation is excessive, it can lead to a loss of toughness and ductility in the material.

Decarburisation is commonly used in the surface hardening or heat treatment of steels. It is particularly useful in applications where high wear resistance is required, such as in gears, axles, and cutting tools. Other uses of decarburisation include the removal of carbonaceous impurities from metal surfaces and the production of steel for general engineering purposes.

There are different methods of decarburisation, including gas carburising and liquid carburising, which involve the use of carbon-rich gases or liquids to remove carbon from the steel surface. In addition, some methods involve the use of flame or torches to heat the surface of the steel, allowing carbon to be locallyised and removed. The choice of decarburisation method depends on the specific requirements of the application and the properties of the steel to be treated.