GH4738 / Waspaloy · UNS N07001 · W. Nr. 2.4654 · GB GH4738
GH4738 / Waspaloy (N07001): composition, properties, fittings and flanges
GH4738 / Waspaloy (N07001, W. Nr. 2.4654, GB GH4738) is Gamma-prime hardened nickel-chromium-cobalt-molybdenum superalloy. GH4738 / Waspaloy is specified at Nickel 58.0 balance, Chromium 18.0 - 21.0, Cobalt 12.0 - 15.0. GH4738 is the Chinese designation for Waspaloy: the standard age-hardenable disc alloy for service to about…
- UNS
- N07001
- W. Nr.
- 2.4654
- Density
- 8.19 g/cm³ (0.296 lb/in³)
- Key strength
- 1100 MPa / 160 ksi
Identification and standards
| Short form | GH4738 / Waspaloy · UNS N07001 · W. Nr. 2.4654 · GB GH4738 |
|---|---|
| Classification | Gamma-prime hardened nickel-chromium-cobalt-molybdenum superalloy |
| UNS | N07001 |
| Werkstoff number | 2.4654 |
| Material family | High-Temperature Alloys / Superalloys |
Chemical composition
| Element | Composition (wt %) | Why it is there |
|---|---|---|
| Nickel (Ni) | 58.0 balance | Matrix |
| Chromium (Cr) | 18.0 - 21.0 | Oxidation resistance |
| Cobalt (Co) | 12.0 - 15.0 | Raises gamma-prime solvus and creep strength |
| Molybdenum (Mo) | 3.50 - 5.00 | Solid-solution strengthening |
| Titanium (Ti) | 2.75 - 3.25 | Gamma-prime former |
| Aluminium (Al) | 1.20 - 1.60 | Gamma-prime former |
| Iron (Fe) | 2.00 max | Residual |
| Carbon (C) | 0.02 - 0.10 | Carbide control |
Note Single figures are maximum limits unless shown as a range. Always confirm against the heat-specific EN 10204 3.1 certificate supplied with your order.
Mechanical properties
| Tensile strength, min (aged) | 1100 MPa / 160 ksi |
|---|---|
| 0.2 % yield strength, min | 760 MPa / 110 ksi |
| Elongation in 2 in, min | 15 % |
| Typical hardness, aged | 32 - 40 HRC |
| Useful continuous service temperature | About 760 °C |
Warning Values depend on product form, section thickness and heat treatment. Larger sections generally achieve lower strength than thin product; always design against the applicable code allowable stress rather than these figures.
Physical properties
| Density | 8.19 g/cm³ (0.296 lb/in³) |
|---|---|
| Melting range | 1330 - 1360 °C (2425 - 2480 °F) |
| Modulus of elasticity | 213 GPa (30.9 x 10⁶ psi) |
| Thermal conductivity at 20 °C | 11.5 W/m·K |
| Mean coefficient of thermal expansion, 20-100 °C | 12.7 µm/m·°C |
| Specific heat capacity | 435 J/kg·K |
Specifications by product form
| Forgings & flanges | ASTM B637 / AMS 5708 / GB/T 14992 (UNS N07001) |
|---|---|
| Butt weld fittings | ASTM B366 (WP grade to order) |
| Seamless pipe & tube | To order |
| Plate / sheet / strip | AMS 5544 / GB/T 14995 |
| Bar / rod | ASTM B637 / AMS 5708 |
| Welding consumables | ERNiCrCoMo-1 or matching Waspaloy filler |
| UNS / EN / China | UNS N07001 · W. Nr. 2.4654 · GB GH4738 |
Product forms available
Hangbo supplies this grade in the following forms. Sizes outside the listed range can often be produced to order.
- Forged flanges blanks and finished flanges to ASME B16.5, B16.47 Series A/B and B16.36
- Butt weld elbows, tees, reducers, caps and stub ends to ASME B16.9 and MSS SP-43
- Seamless pipe and tube to the applicable ASTM / ASME pipe specification
- Forged rings, discs and hubs machined to your drawing
Typical applications
- Gas turbine discs, shafts, spacers and seals
- Aero-engine compressor and turbine rotating parts
- High-temperature fasteners and spring hardware
- Forged rings and flanges for 700 °C class service
Welding, forming and machining
- Welding
- Weldable with matching or ERNiCrCoMo-1 filler in the solution-treated condition, followed by the full ageing cycle. Strain-age cracking is the main risk in restrained joints.
- Heat treatment
- Solution treat at 995 - 1035 °C, oil quench, then stabilise at 845 °C and age at 760 °C for 16 hours.
- Hot and cold forming
- Hot work in the range stated by the mill for this grade, then re-solution or re-age before final machining so that the delivered condition matches the certificate.
- Machining
- Machine with sharp carbide or high-speed steel tooling, positive rake, constant feed and ample coolant. Never dwell - the surface work-hardens quickly.
Buy GH4738 / Waspaloy from Hangbo
Material is supplied with full heat-number traceability, solution annealing or ageing performed under calibrated furnace control, and an EN 10204 3.1 certificate covering chemical analysis, mechanical properties, heat treatment records and the agreed NDT scope. Positive material identification and third party inspection and test reports from SGS are available for critical service.