Keyword: Nimonic 901 UNS N09901
# Nimonic 901 (UNS N09901) Superalloy: Properties and Applications
Introduction to Nimonic 901
Nimonic 901, also known by its UNS designation N09901, is a nickel-based superalloy renowned for its exceptional strength and corrosion resistance at elevated temperatures. Developed by the British company Henry Wiggin & Co. (now part of Special Metals Corporation), this alloy has become a critical material in demanding industrial applications.
Chemical Composition
The outstanding properties of Nimonic 901 stem from its carefully balanced chemical composition:
- Nickel (Ni): 40-45% (base element)
- Chromium (Cr): 11-14%
- Iron (Fe): Balance
- Titanium (Ti): 2.8-3.1%
- Aluminum (Al): 0.9-1.5%
- Carbon (C): ≤0.10%
- Manganese (Mn): ≤1.0%
- Silicon (Si): ≤0.50%
- Copper (Cu): ≤0.50%
- Boron (B): ≤0.01%
Mechanical Properties
Nimonic 901 exhibits remarkable mechanical properties that make it suitable for high-stress applications:
| Property | Value |
|---|---|
| Tensile Strength | 1100-1300 MPa |
| Yield Strength | 700-900 MPa |
| Elongation | 10-20% |
| Hardness | 300-350 HB |
| Density | 8.14 g/cm³ |
Key Characteristics
Several distinctive features make Nimonic 901 stand out among superalloys:
- High-temperature strength: Maintains excellent mechanical properties up to 650°C (1200°F)
- Creep resistance: Outstanding resistance to deformation under constant stress at high temperatures
- Oxidation resistance: Forms a protective chromium oxide layer that prevents further oxidation
- Fatigue resistance: Performs well under cyclic loading conditions
- Good fabricability: Can be forged, machined, and welded with proper techniques
Heat Treatment
Proper heat treatment is crucial for achieving optimal properties in Nimonic 901:
- Solution treatment: 1080-1120°C (1975-2050°F) followed by rapid cooling
- Aging: 775-805°C (1425-1480°F) for 4-8 hours, air cooling
Applications
