9Cr18Mo/440C HIGH CARBON STAINLESS STEEL

Chemiscal composition：

Heat Treatment:

The performance of 440C is highly dependent on heat treatment, typical processes:

1. Austenitizing: heating to 1010-1065°C, oil quenching or air cooling after heat preservation.

2. Temper:

- Low temperature tempering (150-370°C) : maintains high hardness (HRC 58-62), suitable for tools.

- High temperature tempering (> 480°C) : reduces hardness and improves toughness (for impact resistant parts such as bearings).

3. Cryogenic treatment (optional) : Cooling below -80°C to reduce residual austenite and improve dimensional stability.

The specialty of the steel:

Hardness: up to HRC 58-62 after heat treatment (depending on process).

- Wear resistance: Excellent, suitable for high friction environments (e.g. bearings, blades).

- Toughness: relatively low, easy to break (need reasonable design to avoid stress concentration).

Corrosion resistance: better than ordinary carbon steel, but weaker than austenitic stainless steel (such as 304/316).

- Weakness: Long-term exposure to moisture or salt spray may rust, requiring regular maintenance.

Main uses:

- Knives: high-end kitchen knives, surgical instruments, folding knives (need to be polished or coated to prevent rust).

- Bearings: precision ball bearings, valve parts (high load, wear resistance).

- Molds and machinery: plastic molds, measuring tools, wear parts.

- Aerospace: small components with specific corrosion resistance and wear resistance.