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In the aerospace and power generation sectors, material selection for rotating components is dictated by the ability to withstand sustained high stress, thermal cycling, and oxidative atmospheres without microscopic crack propagation. Waspaloy (UNS N07001 / W.Nr. 2.4654), known domestically as GH738, is a precipitation-hardening nickel-based superalloy specifically engineered for these extreme conditions. Shanghai COCESS Special Alloys Co., Ltd supplies certified Waspaloy bar, forging stock, ring rolls, and plate, adhering to rigorous ASTM B637 and AMS specifications, ensuring the microstructural integrity required for critical turbine applications.
Waspaloy derives its strength from a high volume fraction of gamma-prime (γ') precipitates, Ni₃(Al, Ti), within a solid-solution strengthened matrix. The high cobalt content (12-15%) is critical for stabilizing the gamma prime phase and enhancing high-temperature creep resistance.
Chemical Composition (Weight %):
Nickel (Ni): Balance (Approx. 55-58%)
Chromium (Cr): 18.0 – 21.0% (Oxidation resistance)
Cobalt (Co): 12.0 – 15.0% (Solid solution strengthening, γ' stability)
Molybdenum (Mo): 3.5 – 5.0% (Solid solution strengthening)
Titanium (Ti): 2.75 – 3.25% (Primary γ' former)
Aluminum (Al): 1.20 – 1.60% (Primary γ' former)
Iron (Fe): ≤ 2.0%
Carbon (C): 0.02 – 0.10% (Carbide formation)
Boron (B): 0.003 – 0.010% (Grain boundary strengthening)
Zirconium (Zr): 0.02 – 0.08% (Grain boundary strengthening)
The alloy exhibits excellent retention of properties at elevated temperatures, making it suitable for continuous service up to 650°C (1200°F) in critical rotating parts, and up to 870°C (1600°F) in less stressed components.
Physical Constants:
Density: 8.22 g/cm³ (0.297 lb/in³)
Melting Range: 1330 – 1360 °C (2425 – 2475 °F)
Elastic Modulus (20°C): ~214 GPa (31 x 10³ ksi)
Coefficient of Thermal Expansion (20-100°C): 12.2 x 10⁻⁶/°C
Typical Mechanical Properties (Fully Heat Treated Condition):
Room Temp Tensile Strength: 1275 – 1380 MPa (185 – 200 ksi)
Room Temp Yield Strength (0.2%): 795 – 895 MPa (115 – 130 ksi)
Room Temp Elongation: 15 – 25%
Hardness: 32 – 42 HRC
815°C (1500°F) Tensile Strength: ~630 MPa (92 ksi)
815°C (1500°F) Yield Strength: ~520 MPa (75 ksi)
Two attributes distinguish Waspaloy in the superalloy family:
Superior Fatigue Resistance: Compared to Alloy 718 at temperatures exceeding 650°C, Waspaloy offers enhanced fatigue life under cyclic loading, which is vital for turbine discs and blades subjected to centrifugal and vibrational stresses.
Microstructural Stability: The alloy resists over-aging and detrimental phase precipitation (such as sigma or eta phases) effectively within its service temperature range, provided the standard triple-step heat treatment (Solution + Stabilization + Aging) is correctly applied. This ensures long-term dimensional stability and creep resistance.
Shanghai COCESS supplies Waspaloy materials for the manufacture of:
Aerospace Gas Turbines: Turbine disks, compressor disks, blades, shafts, and spacers.
Industrial Gas Turbines (IGT): Rotors, seals, and high-temperature fasteners.
High-Performance Automotive: Turbocharger rotors and exhaust valves.
Oil & Gas: High-temperature downhole tool components requiring high strength and corrosion resistance.
We provide Waspaloy (GH738) in compliance with the following key standards:
Bars, Forgings, Rings: ASTM B637, AMS 5708, AMS 5706
Sheet, Plate, Strip: AMS 5544
Wire: AMS 5828
All materials are supplied with full traceability, ultrasonic testing (UT) options, and EN 10204 3.1/3.2 certification. For technical datasheets, current stock sizes, or inquiries regarding Waspaloy for your turbine engine projects, contact Shanghai COCESS Special Alloys Co., Ltd.
Website: https://en.cocessalloys.com
Email: sales@cocessalloys.com
