Carburising/case hardening

Carburising and carbonitriding are "thermochemical" techniques used to create a high-strength surface on low-carbon steel. Performed at temperatures between 800°C and 940°C, these treatments represent the first stage of the case-hardening process.

By altering the chemical makeup of the steel’s surface, these methods ensure that the final "quenching" (rapid cooling) produces a dual-layer result:

• The Case: A localised, rock-hard exterior that resists wear and tear.
• The Core: A softer, shock-absorbent interior that provides structural toughness.

This combination allows components to be incredibly durable on the outside without becoming brittle throughout.