Carburizing and carbonitriding

Carburizing and carbonitriding are thermochemical surface hardening treatments. They are both used to produce a combination of properties impossible to obtain otherwise – high surface hardness combined with good tenacity and good core ductility.
The result is a real composite material with a macroscopically heterogeneous structure that presents a resilient core and a very hard surface, simultaneously increasing resistance to wear, abrasion and fatigue.

Carburizing Treatment

Thermochemical diffusion treatment with the purpose of carbon enrichment of a surface layer of the treated part. This enrichment is done in a carbon-rich environment. This treatment is always followed by quenching to harden the enriched layer by martensite formation.
This treatment provides the following advantages:

• A hard layer of pre-determined depth.
• Good wear and fatigue resistance.
• Improvement of core hardness to obtain the required resilience.

After deep carburizing, cryogenic treatment is often required to transform the residual austenite. This process makes it possible to avoid cracks due to grinding, obtain dimensional stability and procure better wear resistance and lower friction through a homogeneous martensitic structure.

Carbonitriding Treatment

This treatment consists of enriching the surface of a part with carbon and nitrogen. Always followed by quenching, carbonitriding procures the advantages of both nitriding and carburizing by giving the treated parts greater wear and fatigue resistance and reduces friction.
Thermetco performs the gas carbonitriding process, using industrial gases (methanol, nitrogen and ammonia) in controlled atmosphere furnaces.
This process gives the parts high precision and increased cleanliness. In addition, our perfectly controlled equipment allows us to achieve completely reproducible cycles.
Six furnaces using these processes are available with dimensions as large as Ø 52″ x 90″ (Ø 1320 mm x 2286 mm).