thermochemical processes

process example case hardening

Case hardening is a thermo-chemical process. Within the framework of this process, the surface layer of components is enriched with carbon (carburisation) or carbon and nitrogen (carbonitriding), in order to improve the mechanical properties of the component surface layer. For both process variants, various plant technologies, such as chamber furnaces, through-type furnaces, salt baths, low pressure systems etc., are available.

As a rule, case hardening comprises three working steps. In the first step, the workpieces are exposed to a carbon or carbon and nitrogen rich environment at a temperature of 800 to 1,050 °C. In the second step, the quenching (hardening) may take place either directly from the application temperature or after intermediate cooling and reheating to a material-specific hardening temperature.

The third step, the annealing treatment serves essentially to relieve the highest stresses in the material structure and to reduce sensitivity to grinding cracks.

processes available have a look at our processes!

Available carburizing processes are:

    • Controlled Atmosphere
    • Low Pressure Carburizing (LPC)


Carbonitriding is a case hardening process which also diffuses nitrogen into the surface with the purpose of increasing hardness and wear resistance.

Available nitriding processes are:

    • Gas Nitriding
    • Salt Bath Nitriding
    • Plasma/Ion Nitriding


Available nitrocarburizing processes are:

    • Gas Nitrocarburizing
    • Salt Bath Nitrocarburizing
    • Plasma/Ion Nitrocarburizing


Oxi-Nitrocarburizing is a nitro-carburizing process that includes a post-oxidation-step to increase corrosion resistance and applies an attractive ‘black’ finishing.

The Nitrotec® process is used to enhance the surface and strength characteristics of a range of carbon and low alloy steels. Wear resistance, improved fatigue performance and excellent corrosion resistance are among the properties conferred by this modern surface treatment technology. Such improvements in performance can significantly reduce the manufacturing and materials cost of components, a fact proved repeatedly by the automotive industry on pressed parts.

Stainihard is a hardening technique that allows for the hardening of the surface of stainless steel without reducing  corrosion resistance. The process is based on nitro-carburizing in gas.

Stainitec is a hardening technique that allows for the hardening of the surface of stainless steel through plasma treatment without reducing  corrosion resistance.


get in touch interested in our technologies? please contact us...

Viviane Kettermann-Fernandes
Research & Development
Daniel Guizard
Head of Aalberts Additive Manufacturing