Incoloy 800 · UNS N08800 · W. Nr. 1.4876
Incoloy 800 (N08800): composition, properties, fittings and flanges
Incoloy 800 (N08800, W. Nr. 1.4876) is Iron-nickel-chromium alloy for general high-temperature service. Incoloy 800 is specified at Nickel 30.0 - 35.0, Chromium 19.0 - 23.0, Aluminium 0.15 - 0.60. Incoloy 800 is the base grade of the family: 32 % nickel and 21 % chromium give oxidation and carburisation resistance well above…
- UNS
- N08800
- W. Nr.
- 1.4876
- Density
- 7.94 g/cm³ (0.287 lb/in³)
- Key strength
- 517 MPa / 75 ksi
Identification and standards
| Short form | Incoloy 800 · UNS N08800 · W. Nr. 1.4876 |
|---|---|
| Classification | Iron-nickel-chromium alloy for general high-temperature service |
| UNS | N08800 |
| Werkstoff number | 1.4876 |
| Material family | Incoloy Alloys |
Chemical composition
| Element | Composition (wt %) | Why it is there |
|---|---|---|
| Nickel (Ni) | 30.0 - 35.0 | Austenite stability and carburisation resistance |
| Chromium (Cr) | 19.0 - 23.0 | Oxidation resistance |
| Iron (Fe) | 39.5 min | Matrix |
| Carbon (C) | 0.10 max | - |
| Aluminium (Al) | 0.15 - 0.60 | Oxidation scale adherence |
| Titanium (Ti) | 0.15 - 0.60 | Stabilisation |
| Manganese (Mn) | 1.50 max | - |
| 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 (annealed) | 517 MPa / 75 ksi |
|---|---|
| 0.2 % yield strength, min | 207 MPa / 30 ksi |
| Elongation in 2 in, min | 30 % |
| Typical hardness, annealed | 135 - 185 HB |
| Useful continuous service temperature | About 815 °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 | 7.94 g/cm³ (0.287 lb/in³) |
|---|---|
| Melting range | 1357 - 1385 °C (2475 - 2525 °F) |
| Modulus of elasticity | 196 GPa (28.5 x 10⁶ psi) |
| Thermal conductivity at 20 °C | 11.5 W/m·K |
| Mean coefficient of thermal expansion, 20-100 °C | 14.4 µm/m·°C |
| Specific heat capacity | 460 J/kg·K |
Specifications by product form
| Forgings & flanges | ASTM B564 / ASME SB-564 (UNS N08800) |
|---|---|
| Butt weld fittings | ASTM B366 / ASME SB-366 (WP800) |
| Seamless pipe & tube | ASTM B407 / B163 / ASME SB-407 |
| Plate / sheet / strip | ASTM B409 / ASME SB-409 |
| Bar / rod | ASTM B408 / ASME SB-408 |
| Welding consumables | ERNiCr-3 or ENiCrFe-2 |
| UNS / EN / China | UNS N08800 · W. Nr. 1.4876 · GB NS111 |
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
- Heat exchangers, reformer and cracker outlet piping
- Sheathed electrical heating elements
- Furnace fixtures and heat treatment trays
- Nuclear steam generator tubing in older designs
Welding, forming and machining
- Welding
- Weld with ERNiCr-3 or ENiCrFe-2 filler. No preheat or post-weld heat treatment is normally required for corrosion or oxidation service.
- Heat treatment
- Anneal at 980 - 1065 °C and cool as specified. For creep-critical work, specify 800H or 800HT instead.
- 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 Incoloy 800 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.