6. Glossary

carbon potential of an atmosphere

Carbon mass fraction of a steel in thermodynamic equilibrium with this atmosphere.

standard carbonitriding

Thermochemical treatment is found in most workshops. Practitioners currently limit ammonia injection to no more than 3% of the total volume of gases injected into the furnace.

case-hardening

Thermochemical process for surface carbon enrichment (between 0.7 and 0.9% by mass) by diffusion in the austenitic range (900 to 1,050°C depending on the process), followed by quenching and tempering, if necessary, to obtain a high surface hardness (58 to 62 HRC) with a gradient decreasing over a given depth.