Carburising

What is Carburising?

Carburising is a case-hardening heat-treatment process where carbon atoms diffuse into the surface of stainless steel, creating a hard outer layer while retaining a tough, ductile core. In traditional steel, this takes place at temperatures of 850 °C–950 °C. For stainless steels, advanced methods like low-temperature plasma carburising (300–500 °C) allow high surface hardness without compromising corrosion resistance.

What is the Carburising Process?

Modern low-temperature plasma or gas methods, operating at ~400–500 °C, prevent carbide precipitation, resulting in a precipitation-free, supersaturated layer. The carburising cycle generally follows these phases:

1. Preparation: A low-carbon stainless steel component is placed in a carbon-rich environment.
2. Heating & Carbon Diffusion: Elevated temperatures enable atoms to permeate the surface.
3. Quenching: Rapid cooling converts the enriched surface into hard, wear-resistant martensite.
4. Tempering: Post-quench heating reduces brittleness while maintaining hardness.