Nitrocarburizing is a process for surface hardening of materials. As a result of thermochemical diffusion, the surface layer of the material is enriched with nitrogen and carbon. In contrast to this is nitriding, a process in which only nitrogen is deposited in the surface layer. The compound layer formed through nitrocarburizing is generally thicker, more corrosion resistant and often takes the form of Epsilon Iron Nitride.
Nitrocarburizing can be carried out in different media. The process can take place in gas, in a salt bath or in plasma. In addition, the process takes place at relatively low temperatures. The result is a very hard surface layer, a thin connection layer and the remaining soft core of the material itself. The connecting layer is particularly resistant to corrosion and wear. In contrast to nitriding, however, it is not brittle. This layer therefore contributes significantly to improving the material properties.
The advantages of the process can be seen in the high wear resistance of the material and in the low costs for the treatment.
In addition, a good surface quality is created and the susceptibility of the material to corrosion is reduced. This method can also be used to surface harden elements that have not been pre-tempered.
fields of application
Nitrocarburizing is more commonly applied to low alloy steels, mild steels and cast irons, but can equally be applied to any steel which is thermally stable at the treatment temperatures.