Atmospheric high and low temperature treatments with oil-, polymer- or water quench

Atmospheric high and low temperature heat treatments, usually followed by rapid cooling (quench) in either oil, polymer or water are characterized by an atmosphere consisting carbon-bearing material to either enrich or restore the carbon content at the surface of the part, or just to avoid decarburization. In general you can say that the more carbon the more hardness after quench.Typical heat treatments are: 
Carbon restoration
Neutral hardening

Chamber furnaces: Ø 800 x 800 mm
Pit furnaces: Ø 850 x 2000 mm