Nimonic 90 · UNS N07090 · W. Nr. 2.4632 · GB GH4090
Nimonic 90 (N07090): composition, properties, fittings and flanges
Nimonic 90 (N07090, W. Nr. 2.4632, GB GH4090) is Gamma-prime hardened nickel-chromium-cobalt high-temperature alloy. Nimonic 90 is specified at Nickel Balance, Chromium 18.0 - 21.0, Cobalt 15.0 - 21.0. Nimonic 90 raises cobalt to 15-21 % on top of Nimonic 80A chemistry, which lifts the useful temperature range to roughly 870 °C…
- UNS
- N07090
- W. Nr.
- 2.4632
- Density
- 8.18 g/cm³ (0.295 lb/in³)
- Key strength
- 1080 MPa / 157 ksi
Identification and standards
| Short form | Nimonic 90 · UNS N07090 · W. Nr. 2.4632 · GB GH4090 |
|---|---|
| Classification | Gamma-prime hardened nickel-chromium-cobalt high-temperature alloy |
| UNS | N07090 |
| Werkstoff number | 2.4632 |
| Material family | Nimonic Alloys |
Chemical composition
| Element | Composition (wt %) | Why it is there |
|---|---|---|
| Nickel (Ni) | Balance | Matrix |
| Chromium (Cr) | 18.0 - 21.0 | Oxidation resistance |
| Cobalt (Co) | 15.0 - 21.0 | Raises the gamma-prime solvus and creep strength |
| Titanium (Ti) | 2.00 - 3.00 | Gamma-prime former |
| Aluminium (Al) | 1.00 - 2.00 | Gamma-prime former |
| Carbon (C) | 0.13 max | - |
| Iron (Fe) | 1.50 max | Residual |
| Silicon (Si) | 1.00 max | - |
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 bar) | 1080 MPa / 157 ksi |
|---|---|
| 0.2 % yield strength, min | 690 MPa / 100 ksi |
| Elongation in 2 in, min | 20 % |
| Typical hardness, aged | 310 - 380 HB |
| Useful continuous service temperature | About 870 °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 | 8.18 g/cm³ (0.295 lb/in³) |
|---|---|
| Melting range | 1310 - 1370 °C (2390 - 2500 °F) |
| Modulus of elasticity | 207 GPa (30.0 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 | 446 J/kg·K |
Specifications by product form
| Forgings & flanges | ASTM B637 / BS HR 2 / AMS 5829 (UNS N07090) |
|---|---|
| Butt weld fittings | ASTM B366 (WP grade to order) |
| Seamless pipe & tube | ASTM B167 |
| Plate / sheet / strip | ASTM B168 |
| Bar / rod | ASTM B637 / AMS 5829 |
| Welding consumables | ERNiCr-3 or matching composition; re-age after welding |
| UNS / EN / China | UNS N07090 · W. Nr. 2.4632 · GB GH4090 |
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
- Turbine blades, discs and rings in aero and industrial engines
- Hot-section springs, bolts and fasteners
- High-temperature tooling and hot shear blades
- Creep-critical furnace and reactor internals
Welding, forming and machining
- Welding
- Limited weldability. Weld in the solution-treated condition with ERNiCr-3 or a matching filler, then full solution plus age to recover properties.
- Heat treatment
- Solution treat at 1080 - 1120 °C, then age at 700 - 750 °C for 16 hours and air cool.
- 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 Nimonic 90 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.