9Ni-4Co-25
Alloy Steel9Ni-4Co-25
AISI 9Ni-4Co ultra-high-strength steel.
Chemical Composition (%)
| C | 0.23 |
|---|---|
| SI | 0.1 |
| MN | 0.1 |
| NI | 8.5 |
| CR | 0.65 |
| MO | 0.9 |
| CO | 4 |
| P | 0.01 |
| S | 0.008 |
Applications
High-end / niche grade used in aerospace, defense, tooling, bearing, gear or heavy shaft applications.
Available Forms
Bar, plate, sheet, tube, forgings, strip, wire, powder
Uses
Low-alloy engineering steel with enhanced hardenability and strength from alloying elements. Chromium (≈0.75%) improves hardenability, wear and corrosion resistance. Molybdenum (≈1%) raises high-temperature strength and prevents temper embrittlement. Nickel (≈9%) increases toughness and impact strength at low temperature. Applied to gears, shafts, bolts, connecting rods, pressure parts and heavy forgings in automotive, energy and machinery sectors.
Heat Treatment
Austenitize at 820–870 °C (oil or water quench depending on section) and temper at 400–650 °C to the required strength/toughness balance.
Precautions
Weldable with standard procedures; preheat may be needed for thick sections or higher-carbon/ alloy grades. Protect from decarburization during heating (controlled atmosphere or protective coating).
Comments 0