Hastelloy C-276 · UNS N10276 · W. Nr. 2.4819 · NS334 · NiMo16Cr15W
Hastelloy C-276 (N10276): composition, properties, fittings and flanges
Hastelloy C-276 (UNS N10276, W. Nr. 2.4819, NS334) is the benchmark wrought Ni-Cr-Mo corrosion alloy, with nickel balance, 14.5-16.5 % chromium, 15.0-17.0 % molybdenum, 3.0-4.5 % tungsten and very low carbon (0.01 % maximum) and silicon (0.08 % maximum). Those restrictions allow welded plate structures to be used as-welded…
- UNS
- N10276
- W. Nr.
- 2.4819
- Density
- 8.89 g/cm³ (0.321 lb/in³)
- Key strength
- 690 MPa / 100 ksi
Identification and standards
| Short form | Hastelloy C-276 · UNS N10276 · W. Nr. 2.4819 · NS334 · NiMo16Cr15W |
|---|---|
| Classification | Low-carbon wrought nickel-chromium-molybdenum corrosion resistant alloy |
| UNS | N10276 |
| Werkstoff number | 2.4819 |
| Material family | Hastelloy Alloys |
Chemical composition
| Element | Composition (wt %) | Why it is there |
|---|---|---|
| Nickel (Ni) | Balance | Matrix |
| Chromium (Cr) | 14.5 - 16.5 | Oxidising media resistance |
| Molybdenum (Mo) | 15.0 - 17.0 | Reducing acid resistance, pitting resistance |
| Iron (Fe) | 4.0 - 7.0 | - |
| Tungsten (W) | 3.0 - 4.5 | Additional pitting and crevice resistance |
| Cobalt (Co) | 2.50 max | - |
| Manganese (Mn) | 1.00 max | - |
| Vanadium (V) | 0.35 max | - |
| Silicon (Si) | 0.08 max | Restricted to prevent harmful phase precipitation |
| Carbon (C) | 0.01 max | Restricted for as-welded service |
| Phosphorus (P) | 0.040 max | - |
| Sulphur (S) | 0.030 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 plate, ASTM B575) | 690 MPa / 100 ksi |
|---|---|
| 0.2 % yield strength, min | 283 MPa / 41 ksi |
| Elongation in 2 in, min | 40 % |
| Typical hardness, annealed | 180 - 220 HB (approximately 88 HRB) |
| Typical fatigue strength at 10⁷ cycles | About 240 MPa |
| Practical service range | -198 °C to about 400 °C in reducing process duty |
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 | 8.89 g/cm³ (0.321 lb/in³) |
|---|---|
| Melting range | 1325 - 1370 °C (2417 - 2500 °F) |
| Modulus of elasticity | 205 GPa (29.8 x 10⁶ psi) |
| Thermal conductivity at 20 °C | 9.8 W/m·K |
| Mean coefficient of thermal expansion, 20-100 °C | 11.2 µm/m·°C |
| Electrical resistivity at 20 °C | 1.30 µΩ·m |
Specifications by product form
| Plate / sheet / strip | ASTM B575 / ASME SB-575 |
|---|---|
| Bar / rod / wire | ASTM B574 / ASME SB-574 |
| Seamless pipe & tube | ASTM B622 / ASME SB-622 |
| Welded pipe & tube | ASTM B619 / B626 |
| Forgings & flanges | ASTM B564 / ASME SB-564 (UNS N10276) |
| Butt weld fittings | ASTM B366 / ASME SB-366 (WP276 / WPHC276) |
| Welding consumables | ERNiCrMo-4 wire, ENiCrMo-4 electrode |
| UNS / EN / China | UNS N10276 · EN NiMo16Cr15W · W. Nr. 2.4819 · GB NS334 |
Product forms available
Hangbo supplies this grade in the following forms. Sizes outside the listed range can often be produced to order.
- Seamless and welded pipe and tube
- Forged flanges to ASME B16.5 Class 150-2500
- Butt weld elbows, tees, reducers and stub ends to ASME B16.9
- Machined reactor internals, agitators, trays and heat exchanger parts
Typical applications
- Flue gas desulphurisation scrubbers, dampers, stack liners and reheaters
- Chemical reactors handling mixed acids, acetic anhydride and acid chlorides
- Pulp and paper bleach plants using chlorine dioxide
- Pharmaceutical and fine chemical reactors requiring zero metal contamination
- Waste incineration, municipal sludge and hazardous waste treatment
- Pickling line equipment handling contaminated hydrochloric and sulphuric acids
- Sour gas handling and geothermal brine systems
Welding, forming and machining
- Welding
- Excellent as-welded corrosion performance. Use GTAW or GMAW with ERNiCrMo-4 filler, low heat input below about 1.5 kJ/mm, interpass temperature below 100 °C and argon backing shielding on the root pass to avoid sugaring.
- Hot forming
- Solution anneal at 1120-1175 °C then water quench. Hot work between 1175 °C and 950 °C; avoid prolonged exposure in the 550-1100 °C range, which precipitates mu and sigma phases.
- Machining
- High work-hardening rate. Use sharp carbide with positive rake, generous depth of cut, low-to-medium speeds and flood coolant.
- Pickling
- Descale by grit blasting followed by an HF-HNO₃ pickle. Sulphur-bearing cutting fluids must be removed before any high-temperature exposure.
Buy Hastelloy C-276 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.