Nimonic 263 · UNS N07263 · W. Nr. 2.4650
Nimonic 263 (N07263): composition, properties, fittings and flanges
Nimonic 263 (N07263, W. Nr. 2.4650) is Gamma-prime hardened nickel-chromium-cobalt-molybdenum alloy. Nimonic 263 is specified at Nickel Balance, Chromium 19.0 - 21.0, Cobalt 19.0 - 21.0. Nimonic 263 is a weldable age-hardenable Nimonic grade: molybdenum gives solid-solution strength and the controlled carbon plus titanium and…
- UNS
- N07263
- W. Nr.
- 2.4650
- Density
- 8.36 g/cm³ (0.302 lb/in³)
- Key strength
- 1000 MPa / 145 ksi
Identification and standards
| Short form | Nimonic 263 · UNS N07263 · W. Nr. 2.4650 |
|---|---|
| Classification | Gamma-prime hardened nickel-chromium-cobalt-molybdenum alloy |
| UNS | N07263 |
| Werkstoff number | 2.4650 |
| Material family | Nimonic Alloys |
Chemical composition
| Element | Composition (wt %) | Why it is there |
|---|---|---|
| Nickel (Ni) | Balance | Matrix |
| Chromium (Cr) | 19.0 - 21.0 | Oxidation resistance |
| Cobalt (Co) | 19.0 - 21.0 | Creep strength |
| Molybdenum (Mo) | 5.60 - 6.10 | Solid-solution strengthening |
| Titanium (Ti) | 1.90 - 2.40 | Gamma-prime former |
| Aluminium (Al) | 0.60 max | Gamma-prime former |
| Carbon (C) | 0.04 - 0.08 | Grain boundary carbide control |
| Iron (Fe) | 0.70 max | Residual |
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) | 1000 MPa / 145 ksi |
|---|---|
| 0.2 % yield strength, min | 620 MPa / 90 ksi |
| Elongation in 2 in, min | 25 % |
| Typical hardness, aged | 290 - 350 HB |
| Useful continuous service temperature | About 850 °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 | 8.36 g/cm³ (0.302 lb/in³) |
|---|---|
| Melting range | 1300 - 1360 °C (2370 - 2480 °F) |
| Modulus of elasticity | 208 GPa (30.2 x 10⁶ psi) |
| Thermal conductivity at 20 °C | 11.0 W/m·K |
| Mean coefficient of thermal expansion, 20-100 °C | 12.3 µm/m·°C |
| Specific heat capacity | 461 J/kg·K |
Specifications by product form
| Forgings & flanges | ASTM B637 / BS HR 206 / AMS 5872 (UNS N07263) |
|---|---|
| Butt weld fittings | ASTM B366 (WP grade to order) |
| Seamless pipe & tube | ASTM B167 |
| Plate / sheet / strip | ASTM B168 / AMS 5872 |
| Bar / rod | ASTM B637 |
| Welding consumables | Matching composition or ERNiCrCoMo-1; age after welding |
| UNS / EN / China | UNS N07263 · W. Nr. 2.4650 |
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
- Combustion chambers, casings and exhaust ducting
- Transition ducts and hot gas path fabrications
- Welded sheet structures that must be age-hardened afterwards
- Land-based turbine hot-section components
Welding, forming and machining
- Welding
- One of the few age-hardenable Nimonic grades considered readily weldable. Use matching filler, moderate heat input, and re-solution plus age after welding to restore creep strength.
- Heat treatment
- Solution treat at 1150 °C, then age at 800 °C for 8 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 263 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.