Technical Specifications
Chemical Composition
- Carbon (C): 0.50–0.60% – Provides base strength and contributes to hardenability.
- Silicon (Si): 0.10–0.40% – Improves strength and supports deoxidisation.
- Manganese (Mn): 0.60–0.95% – Enhances toughness and ductility.
- Chromium (Cr): 1.50–1.80% – Offers high hardenability and wear resistance.
- Nickel (Ni): 1.50–1.80% – Increases toughness and low-temperature strength.
- Molybdenum (Mo): 0.45–0.55% – Boosts elevated temperature strength and hardenability.
- Vanadium (V): 0.07–0.12% – Refines grain structure and improves strength and wear resistance.
- Phosphorus (P): ≤ 0.030% – Limits brittleness and ensures soundness.
- Sulfur (S): ≤ 0.030% – Maintains machinability and finish quality.
Treatment
- Pre-Hardening / Annealing: Heat to approx. 760–780 °C, hold, then furnace cool or air cool to achieve approx. 248 HB max for machining readiness.
- Hardening: Austenitise at around 840–860 °C, hold to achieve full transformation; quench in oil or air depending on section size for maximum hardenability.
- Tempering: Immediately temper after quenching; typical tempering temperature range 400–650 °C depending on desired hardness/toughness balance (e.g., 46 HRC approx.).
- Finishing: After heat treatment, tool steel can be polished or coated for enhanced wear/corrosion resistance; minimal section distortion due to high hardenability.
