Discover the latest trends and innovations in the nickel alloy industry. We provide expert insights and in-depth analysis on the newest developments in nickel alloys.
GH738 (commercially known as Waspaloy, UNS N07001) is a precipitation-hardening nickel-chromium-cobalt-molybdenum superalloy. It is specifically engineered for critical rotating and stationary components in aerospace engines and industrial gas turbines, offering an optimal balance of high tensile strength, creep resistance, and oxidation stability up to 870°C (1600°F). Shanghai COCESS Special Alloys Co., Ltd stands as a reliable manufacturer and supplier of this premium-grade alloy, delivering certified materials that meet rigorous international aerospace and energy standards.
Chemical Composition & Metallurgical Characteristics
The superior performance of GH738 is driven by its high Cobalt content and the precise ratio of Aluminum and Titanium, which form the gamma prime [γ′-Ni₃(Al, Ti)] precipitates responsible for its age-hardening capability.
Chemical Composition (%): Ni Bal., Cr 18.0–21.0, Co 12.0–15.0, Mo 3.5–5.0, Ti 2.75–3.25, Al 1.2–1.6, Fe ≤ 2.0, C 0.03–0.10, B 0.003–0.010, Zr 0.02–0.08.
Strengthening Mechanism: Precipitation hardening via γ′ phase, supplemented by solid solution strengthening from Co, Cr, and Mo, and grain boundary strengthening via B and Zr.
Physical Properties: Density 8.22 g/cm³; Melting Range 1330–1360°C; Non-magnetic.
Mechanical Properties & High-Temperature Performance
In its fully heat-treated condition (solution treated + double aged), GH738 exhibits high strength and excellent creep-rupture resistance, making it ideal for high-stress, high-temperature environments.
Room Temperature: Tensile Strength ≥ 1200 MPa, Yield Strength ≥ 800 MPa, Elongation ≥ 15%, Hardness HRC 30–38.
Elevated Temperature: Retains a tensile strength of ≥ 900 MPa at 650°C and ≥ 608 MPa at 815°C.
Creep Rupture: Exhibits a stress rupture life exceeding 23 hours at 815°C / 328 MPa, ensuring long-term dimensional stability under load.
Oxidation Resistance: Forms a protective Cr₂O₃ scale; in air at 900°C, the oxidation rate is approximately 0.083 g/(m²·h), suitable for prolonged exposure to combustion gases.
Product Forms & Manufacturing Standards
Shanghai COCESS Special Alloys Co., Ltd supplies GH738 in various metallurgically processed forms to suit specific component manufacturing routes:
Bars & Forgings: Produced via Vacuum Induction Melting (VIM) + Vacuum Arc Remelting (VAR) to ensure ultra-high purity and structural homogeneity. Compliant with ASTM B637, AMS 5706, AMS 5707, AMS 5708.
Rings & Discs: Seamless rolled rings and forged discs for turbine rotors and cases.
Sheets & Plates: AMS 5596, used for combustion chamber components and casings.
Heat Treatment: Supplied in the fully heat-treated condition (e.g., 1080°C solution + 840°C/24h age + 760°C/16h age) to guarantee immediate usability for machining.
Key Applications in Aerospace & Gas Turbines
GH738 is predominantly utilized in the "hot section" of engines and turbines where components endure extreme centrifugal forces, thermal gradients, and corrosive combustion byproducts.
Aerospace Engines: Turbine disks (rotors), compressor disks, high-pressure shaft components, turbine blades (in some medium-temperature designs), and high-strength fasteners (bolts, nuts).
Industrial Gas Turbines (IGT): Land-based power generation turbine discs, blades, seals, and casings; components in offshore/marine gas turbines requiring resistance to salt fog and sulfur-containing fuels.
Other Energy Sectors: Components for nuclear applications and high-temperature petrochemical processing (e.g., turbo-expanders).
Quality Assurance & Traceability
As a dedicated superalloy manufacturer, Shanghai COCESS Special Alloys Co., Ltd ensures that every batch of GH738 is accompanied by an EN 10204 3.1 Certificate, detailing full chemical analysis, mechanical test results (room temp and high temp), and non-destructive testing (Ultrasonic Testing UT, Penetrant Testing PT) reports. We support third-party inspections and provide technical data packages required for aerospace qualification.
For inquiries regarding GH738 bars, forgings, or rings, including available diameters, heat treatment conditions, and lead times, please contact our technical sales team at Shanghai COCESS Special Alloys Co., Ltd.
Website: https://en.cocessalloys.com
Email: sales@cocessalloys.com
