Decarburierung

Decarburization is a metallurgical process that involves the removal of carbon from the surface of a metal, typically steel. This process is often undesirable as it can degrade the mechanical properties of the material, such as hardness and strength. Decarburization occurs when steel is heated in an atmosphere that is not protective, such as air or a reducing atmosphere, which allows carbon to escape from the surface of the steel.

The primary cause of decarburization is the diffusion of carbon atoms from the surface of the steel to the surrounding atmosphere. This diffusion is driven by the concentration gradient between the steel and the atmosphere. The rate of decarburization depends on several factors, including the temperature, the composition of the atmosphere, and the time of exposure.

Decarburization can be mitigated by using a protective atmosphere, such as a vacuum or an inert gas, during the heating process. This prevents the carbon from escaping and allows the steel to be heated without significant loss of carbon. Additionally, the use of alloying elements, such as chromium, can improve the resistance of steel to decarburization.

The effects of decarburization on steel include a reduction in hardness and strength, as well as an increase in ductility and toughness. This is because the loss of carbon from the surface of the steel results in a decrease in the amount of hard, brittle carbides that are formed during the heat treatment process. As a result, decarburization can have a significant impact on the performance of steel components in applications where hardness and strength are critical.