- ≥ 690MPa tensile, annealed
- ≥ 275MPa 0.2% proof stress
- ≥ 40 %Elongation
- ≈ 74PREN, pitting index
- 3.1 / 3.2EN 10204 certificates
What is NW0276?
NW0276 is the grade designation used by the Japanese Industrial Standards for wrought alloy C-276. It appears in JIS H4551 (nickel and nickel alloy plate, sheet and strip), JIS H4552 (seamless pipe and tube), JIS H4553 (welded pipe and tube), JIS H4554 (rod and bar) and JIS G4902. The same material is registered as UNS N10276 in North America, W.Nr. 2.4819 / NiMo16Cr15W in Germany and NiMo16Cr15Fe6W4 in ISO 6207. NW0276, UNS N10276 and Alloy C-276 are three names for one chemistry. They are not different materials, and a drawing calling for any one of them can be satisfied by the others.
The alloy is a solid-solution-strengthened nickel base. Molybdenum at 15 to 17 percent carries resistance to reducing acids, chromium at 14.5 to 16.5 percent covers oxidising conditions, and tungsten at 3 to 4.5 percent reinforces both. What separates C-276 from the earlier alloy C is the deliberate suppression of carbon to 0.010% maximum and silicon to 0.08% maximum. Those two limits stop carbides and mu phase from forming along grain boundaries during welding. NW0276 is therefore one of the few high-alloy materials normally accepted in service as welded, with no post-weld solution anneal.
NW0276 cannot be age hardened or precipitation hardened. It is strengthened only by solid solution and by cold work. Any ageing cycle between roughly 650 °C and 1090 °C precipitates mu phase, P phase and M6C carbides that destroy both ductility and corrosion resistance. The only correct heat treatment is a full solution anneal followed by a rapid quench. See section 9.
We supply NW0276 as forged product only: open-die forgings and seamless rolled rings, made to customer drawing. Forging closes ingot porosity and directs grain flow along the hoop in rings and along the axis in shafts, which matters in the thick sections used for pressure-retaining parts.
NW0276 designation cross-reference
Buyers reach this grade through many different standards, and purchase documents often mix them. The table below is the mapping we work to. If your drawing quotes any designation in the right-hand column, we can forge it as NW0276.
| Standards system | Designation | Scope / notes |
|---|---|---|
| JIS (Japan) | NW0276 | H4551, H4552, H4553, H4554, G4902 |
| UNS (USA) | N10276 | Unified Numbering System, wrought nickel alloy |
| Werkstoff / EN | 2.4819 | German material number |
| DIN chemical name | NiMo16Cr15W | DIN 17744, 17750, 17751, 17752 |
| ISO | NiMo16Cr15Fe6W4 | ISO 6207; ISO 9723 bar, ISO 9725 forgings |
| Common trade name | Alloy C-276 / C276 | Also written Hastelloy® C-276, Inconel® C-276 |
| GB/T (China) | NS3304 | GB/T 15007 corrosion-resistant alloy grade |
| GOST (Russia) | KhN65MVU / EP760 | Nearest listed equivalent |
| BS (UK) | NA48 | BS 2901 Part 5, welding consumable |
| AMS | AMS 5750 | Bar, forgings and forging stock |
| Welding filler | ERNiCrMo-4 / ENiCrMo-4 | AWS A5.14 wire, AWS A5.11 covered electrode |
Table compiled by Jiangyin Jiangnan Metal Co., Ltd. from published national standards and alloy cross-reference data. Where a nearest-equivalent is shown, chemistry limits differ slightly between systems and the governing specification on the purchase order takes precedence.
Standards NW0276 forgings are ordered to
- ASTM B564 / ASME SB-564: nickel alloy forgings. The primary specification for the parts on this page.
- ASTM B462 / ASME SB-462: forged or rolled alloy pipe flanges, forged fittings, valves and parts for corrosive service.
- ASTM B574 / ASME SB-574: rod, bar and wire.
- ISO 9725: nickel and nickel alloy forgings. ISO 9723: rod and bar.
- AMS 5750: bar, forgings and forging stock.
- VdTÜV Werkstoffblatt 400: European pressure-equipment approval for the grade.
- NACE MR0175 / ISO 15156-3: listed for sour oilfield service.
- ASME Boiler and Pressure Vessel Code: approved construction material. allowable stresses are published in Section II Part D for Section VIII Division 1 service to 677 °C (1250 °F), and to 427 °C (800 °F) for Section III and Section VIII Division 2.
Why NW0276 is specified
- It handles oxidising and reducing conditions in the same part. Most corrosion-resistant alloys are good at one or the other. The chromium–molybdenum–tungsten balance in NW0276 covers both, which is why it is chosen for multipurpose plant and for processes with upset conditions.
- It survives wet chlorine, hypochlorite and chlorine dioxide. Few other structural metals do. Pulp bleaching and flue-gas desulfurisation are built around this property.
- It resists chloride pitting and crevice corrosion. With a pitting resistance equivalent number near 74, NW0276 sits well above super duplex and 6% Mo austenitics.
- It resists chloride stress-corrosion cracking. A high-nickel matrix removes the failure mode that limits 304 and 316 in hot chloride service.
- It can be used as welded. Low carbon and low silicon suppress heat-affected-zone sensitisation, so large fabrications do not need a post-weld solution anneal. That saves both cost and programme time on site-welded vessels.
- It is listed for sour service. NACE MR0175 / ISO 15156-3 acceptance makes it a default for wellhead and subsea hardware exposed to H2S.
- It is stable in oxidising atmospheres to about 1038 °C (1900 °F), which covers incinerator and scrubber duct hardware.
Chromium is relatively low for this alloy class, so NW0276 is not the best grade for hot, strongly oxidising acids, concentrated nitric acid in particular. For those services consider Alloy C-22, Alloy 59 or Alloy 690. NW0276 is also not a high-strength grade: if the part is load-bearing rather than corrosion-driven, Inconel 718 or Inconel 725 will carry three to four times the yield stress. If a cheaper grade will do the job, we will say so on the quotation.
Chemical composition of NW0276
The table below is the specification range we forge to, consistent with UNS N10276 and JIS NW0276. Every heat is supplied with a ladle analysis on the mill certificate; product analysis from the finished forging can be added on request.
| Element | Symbol | Min % | Max % | Function in the alloy |
|---|---|---|---|---|
| Nickel | Ni | Balance | Balance | Austenitic matrix; immunity to chloride stress-corrosion cracking |
| Molybdenum | Mo | 15.0 | 17.0 | Resistance to reducing acids, pitting and crevice attack |
| Chromium | Cr | 14.5 | 16.5 | Passive film for oxidising media and high-temperature oxidation |
| Tungsten | W | 3.0 | 4.5 | Reinforces both the oxidising and reducing resistance |
| Iron | Fe | 4.0 | 7.0 | Matrix element, phase stability |
| Cobalt | Co | – | 2.5 | Residual; restricted for nuclear service |
| Manganese | Mn | – | 1.0 | Deoxidiser, sulphur control |
| Vanadium | V | – | 0.35 | Residual limit |
| Phosphorus | P | – | 0.04 | Impurity limit |
| Sulphur | S | – | 0.03 | Impurity limit; hot-workability |
| Carbon | C | – | 0.010 | Held very low to prevent grain-boundary carbides in the weld HAZ |
| Silicon | Si | – | 0.08 | Held very low to suppress mu-phase precipitation |
Source: Jiangyin Jiangnan Metal Co., Ltd., NW0276 forging specification, consistent with UNS N10276 and JIS NW0276 limits. Nominal mid-range chemistry is 57 Ni / 16 Mo / 15.5 Cr / 3.8 W / 5.5 Fe.
Pitting resistance equivalent number
For nickel–chromium–molybdenum alloys containing tungsten the PREN is calculated as PREN = %Cr + 3.3 (%Mo + 0.5 %W). Using mid-range chemistry, NW0276 gives 15.5 + 3.3 × (16.0 + 1.88) = ≈ 74. For comparison, 316L is about 24 and super duplex 2507 about 42. Reported critical pitting temperatures for C-276 in ASTM G48 ferric chloride testing exceed 85 °C.
Mechanical properties of forged NW0276
The values below are the room-temperature minima we certify for solution-annealed forgings. Actual results on the mill certificate normally run above these minima. NW0276 is not hardenable by heat treatment, so a higher strength requirement can only be met by cold work, and cold work above roughly 7% outer-fibre elongation must be followed by a re-anneal if full corrosion resistance is required.
| Property | Metric | Imperial | Test method |
|---|---|---|---|
| Ultimate tensile strength | ≥ 690 MPa | ≥ 100 ksi | ASTM E8 / ISO 6892-1 |
| Yield strength, 0.2% offset | ≥ 275 MPa | ≥ 40 ksi | JIS / EN minimum |
| Yield strength, 0.2% offset | ≥ 283 MPa | ≥ 41 ksi | ASTM B564 / B574 minimum |
| Elongation in 4D | ≥ 40 % | ≥ 40 % | ASTM E8 |
| Reduction of area, typical | ≥ 50 % | ≥ 50 % | ASTM E8 |
| Hardness, annealed | ≤ 100 HRB | typ. 85–95 HRB | ASTM E18 |
| Modulus of elasticity | 205 GPa | 29 700 ksi | Dynamic method |
| Impact toughness, typical | > 200 J at −196 °C | > 148 ft-lb | ASTM E23 Charpy V |
| Grain size | ASTM 4 or finer | ASTM 4 or finer | ASTM E112 |
Source: Jiangyin Jiangnan Metal Co., Ltd. Values apply to the solution-annealed condition. For sour service, NACE MR0175 / ISO 15156-3 caps hardness at 100 HRB for the solution-annealed grade. State this on the enquiry and we will certify against it.
Physical and thermal properties
| Property | Metric | Imperial |
|---|---|---|
| Density | 8.89 g/cm³ | 0.321 lb/in³ |
| Melting range | 1325–1370 °C | 2415–2500 °F |
| Specific heat, 21 °C | 427 J/kg·K | 0.102 BTU/lb·°F |
| Thermal conductivity, 21 °C | 10.2 W/m·K | 70.8 BTU·in/hr·ft²·°F |
| Thermal expansion, 20–100 °C | 11.2 µm/m·°C | 6.2 µin/in·°F |
| Electrical resistivity, 21 °C | 1.30 µΩ·m | 130 µΩ·cm |
| Modulus of elasticity | 205 GPa | 29 700 ksi |
| Poisson's ratio | 0.31 | 0.31 |
| Magnetic permeability | ≈ 1.0002 (non-magnetic) | Curie point below −200 °C |
Source: Jiangyin Jiangnan Metal Co., Ltd., consolidated from published UNS N10276 / JIS NW0276 datasheets. Values are for the solution-annealed condition.
Corrosion resistance of NW0276
NW0276 was developed for plant where the process stream is aggressive, variable, or both. The summary below reflects generally published behaviour for the grade. Use it for shortlisting, not as a substitute for coupon testing in your own medium. Temperature, concentration, aeration, velocity and contaminants all move the result.
| Medium | Behaviour | Typical service |
|---|---|---|
| Wet chlorine gas, hypochlorite, chlorine dioxide | Excellent. One of very few metals that hold up | Pulp bleaching, chlor-alkali |
| Ferric and cupric chlorides | Excellent, including hot and contaminated streams | Etchants, leach circuits |
| Seawater and brines | Excellent; resists crevice attack under deposits and gaskets | Offshore, desalination, heat exchangers |
| Sulphuric acid | Good across the concentration range at low to moderate temperature | Acid plant, pickling |
| Hydrochloric acid | Good at low to medium concentration and temperature | Regeneration, pickling |
| Phosphoric acid | Excellent, including contaminated wet-process acid | Fertiliser plant |
| Formic and acetic acid, acetic anhydride | Excellent | Organic chemicals |
| Sour gas, H2S with chlorides | Excellent; listed in NACE MR0175 / ISO 15156-3 | Wellhead, subsea, downhole |
| Flue gas with sulphur and chlorides | Excellent. The default material for scrubbers | FGD absorbers, ducts, quench zones |
| Hot concentrated nitric acid | Limited. Chromium is low for this duty | Use Alloy C-22, Alloy 59 or Alloy 690 |
| Oxidising atmospheres, dry | Stable to about 1038 °C (1900 °F) | Incinerator hardware, ducting |
Source: Jiangyin Jiangnan Metal Co., Ltd., compiled from published Alloy C-276 corrosion literature. Verify against your own process data before final material selection.
NW0276 compared with Alloy C-22 and Alloy 625
These three grades overlap on many enquiries. In short, NW0276 suits reducing and chloride service, C-22 suits oxidising conditions, and Alloy 625 is the choice where the part needs strength as well as corrosion resistance.
| Attribute | NW0276 / C-276 | Alloy C-22 | Alloy 625 |
|---|---|---|---|
| UNS number | N10276 | N06022 | N06625 |
| JIS designation | NW0276 | NW6022 | NW6625 |
| Werkstoff | 2.4819 | 2.4602 | 2.4856 |
| Chromium | 14.5–16.5 % | 20.0–22.5 % | 20.0–23.0 % |
| Molybdenum | 15.0–17.0 % | 12.5–14.5 % | 8.0–10.0 % |
| Tungsten | 3.0–4.5 % | 2.5–3.5 % | – |
| Niobium | – | – | 3.15–4.15 % |
| PREN, approx. | ≈ 74 | ≈ 68 | ≈ 51 |
| Yield strength, min | 275 MPa | 310 MPa | 414 MPa (Gr 1) |
| Strongest in | Reducing acids, chlorides, wet chlorine | Oxidising acids, mixed and upset streams | Strength plus general corrosion resistance |
| Relative cost | High | Highest | Lower |
| Typical duty | FGD, pulp bleaching, sour wells | Waste incineration, mixed-acid plant | Piping, bellows, structural CRA parts |
Table compiled by Jiangyin Jiangnan Metal Co., Ltd. See also Alloy C-22 forgings and Alloy 625 forgings.
Forging window and heat treatment
NW0276 has a narrow hot-working window and is more sensitive to strain rate than austenitic stainless steel. Forged C-276 that reaches site with none of its corrosion resistance left has almost always been worked or cooled outside this window.
| Operation | Temperature | Hold | Cooling |
|---|---|---|---|
| Forging start | 1232 °C (2250 °F) max | Soak to uniform through-temperature | – |
| Forging finish | 954 °C (1750 °F) min | Moderate reductions, frequent reheats | Air |
| Solution anneal | 1121–1160 °C (2050–2120 °F) | 10–30 min, or 1 h per 25 mm of section | Water quench (mandatory) |
| Re-anneal after cold work | 1121 °C (2050 °F) | Required above ≈7 % outer-fibre elongation | Water quench |
| Age / precipitation hardening | Not applicable | The alloy cannot be hardened by heat treatment | – |
| Stress relief | Not effective | Use a full solution anneal instead | Water quench |
Source: Jiangyin Jiangnan Metal Co., Ltd. Furnace time–temperature charts for every load are issued with the mill certificate. Sections thinner than 10 mm may be rapidly air cooled; everything heavier is water quenched.
Between roughly 1090 °C and 650 °C, NW0276 precipitates mu phase, P phase and M6C carbides at grain boundaries. A slow cool through that band leaves a forging that still passes tensile and hardness testing but has lost a large part of its resistance to intergranular and localised attack. We water quench for that reason, re-anneal after every hot-forming operation, and do not accept a stress-relief cycle as a substitute.
How Jiangyin Jiangnan Metal forges NW0276
The route below is what we run for every NW0276 order. Each stage produces a record that goes into the documentation pack.
Melt route and billet sourcing
Billet is accepted only against documented EAF plus AOD or VOD refining followed by ESR, or VIM plus ESR. The refining step is what holds carbon at 0.010% and silicon at 0.08%, the two limits the whole grade depends on. Single-melt material is not accepted.
Incoming verification
Heat certificate checked against the order, plus positive material identification by XRF or optical emission on every billet before it enters the shop. Mo and W are checked because that is where substitution risk sits.
Billet conditioning and pre-heat
Surfaces are ground clean, then the billet is soaked to a uniform through-temperature. Under-soaked nickel alloy splits on the first blow, and NW0276 is less forgiving than most.
Open-die forging, 1232 down to 954 °C
Hydraulic press forging with moderate reductions and frequent reheats. The window is narrow and the alloy is strain-rate sensitive, so we forge it slower and reheat more often than we would carbon or alloy steel. Grain flow is directed along the hoop in rings and along the axis in shafts.
Ring rolling or upsetting to shape
Seamless rings are pierced and rolled to the finished envelope; discs are upset and punched. Both routes keep continuous grain flow with no cut fibres at the bore.
Solution anneal and water quench
Charged in calibrated furnaces at 1121–1160 °C, held to section thickness, then water quenched. Recorded time and temperature charts cover the whole load. This step is repeated after any subsequent hot or cold forming.
Descale and pickle
Oxide and any chromium-depleted surface layer is removed. A forging that leaves the works with mill scale on it will pit under the scale in service.
Rough or finish machining
Supplied as-forged, rough machined to an agreed allowance, or finish machined to drawing tolerance. Carbide tooling, positive rake, rigid setup, heavy feeds and flood coolant. NW0276 work hardens if you dwell in the cut.
Non-destructive and mechanical testing
Ultrasonic testing to EN 10228-3, SEP 1921 or ASTM A388. Liquid penetrant to ASTM E165 (magnetic particle does not apply, the alloy is non-magnetic). Tensile, hardness and grain size from prolongations. Intergranular corrosion testing to ASTM G28 Method A on request.
Marking, certification and packing
Hard-stamped or vibro-etched heat number and part identification, EN 10204 3.1 certificate, or 3.2 counter-signed by TÜV, BV, SGS or Lloyd's Register, then seaworthy packing.
NW0276 forged forms and size capability
All parts are made to your drawing or dimensional sketch. There is no fixed catalogue. The range below covers what we forge regularly in NW0276.
| Forged form | Size range | Common uses |
|---|---|---|
| Seamless rolled rings | OD 200–4000 mm, H ≤ 1000 mm | Scrubber shell rings, casing rings, flange blanks |
| Forged discs and blanks | Dia. 150–2500 mm | Blind flanges, tube sheets, closure heads |
| Forged shafts and spindles | Dia. 80–1200 mm, L ≤ 8000 mm | Pump shafts, agitator shafts, stub shafts |
| Round bars | Dia. 20–800 mm | Valve stems, fasteners, machining stock |
| Forged flanges | DN 15–1500, ASME B16.5 / B16.47 / EN 1092-1 | Piping, vessels, exchangers, to ASTM B462 |
| Sleeves, bushings, hollow bars | OD 100–1200 mm | Wear sleeves, liners, bearing housings |
| Forged blocks and rectangles | Up to 800 × 1500 mm section | Valve bodies, manifolds, wellhead blocks |
| Tube sheets and nozzles | Dia. up to 3000 mm | Shell-and-tube exchangers, pressure vessels |
| Single-piece weight | 20 kg to 15 000 kg | Heavier pieces quoted case by case |
Source: Jiangyin Jiangnan Metal Co., Ltd. Delivery conditions: as-forged, solution annealed and pickled, rough machined, or finish machined. Equipment includes 1, 3, 5 and 9 tonne forging hammers, a 5000 tonne hydraulic press and 3 m and 6 m ring-rolling mills.
Where NW0276 forgings are used
NW0276 is chosen when the cost of a corrosion failure (unplanned shutdown, contaminated product, a hazardous leak) is far larger than the cost of the metal. The industries below account for most of what we forge in this grade.
Flue-gas desulfurisation
The default material for FGD absorbers. Wet scrubber environments combine sulphurous acid, chlorides and abrasive slurry, and NW0276 is the grade specified when the alloy has to survive upset chemistry rather than design chemistry.
Pulp and paper bleaching
Chlorine dioxide, hypochlorite and wet chlorine attack almost every other structural metal. NW0276 handles the D and C stages of the bleach plant.
Oil, gas and subsea
Sour service with H2S and chlorides, where the grade's NACE MR0175 / ISO 15156-3 listing and its resistance to sulphide stress cracking are the deciding factors.
Chemical and pharmaceutical process
Multipurpose reactors and campaign plant where the process stream changes between products and the material has to cover both oxidising and reducing conditions.
Waste treatment and incineration
Municipal and industrial waste streams with variable halide and sulphur content, plus dry oxidising service in ductwork up to about 1038 °C.
Marine, offshore and desalination
Seawater and concentrated brine, where the failure mode that matters is crevice corrosion under gaskets and deposits rather than general corrosion.
Testing, inspection and certification
Every NW0276 forging ships with a documentation pack. The content is agreed before production starts.
- Chemical analysis: ladle analysis on every heat; product analysis from the finished forging on request. Mo, Cr and W verified by XRF or OES at goods-in.
- Mechanical testing: tensile, 0.2% proof stress, elongation, reduction of area and hardness, taken from integral or separately forged prolongations.
- Ultrasonic testing: EN 10228-3, SEP 1921 Class C, D or E, ASTM A388, or a customer acceptance class.
- Surface NDT: liquid penetrant to ASTM E165. Magnetic particle is not applicable: NW0276 is non-magnetic.
- Intergranular corrosion testing: ASTM G28 Method A, the standard check that the anneal and quench were done correctly. Recommended on every pressure-retaining part.
- Grain size and microstructure: ASTM E112, with metallographic confirmation that no continuous grain-boundary precipitation is present.
- Positive material identification: on the finished part, before packing, where the end user requires it.
- Dimensional report against the drawing.
- Certification: EN 10204 3.1 as standard, or 3.2 witnessed and counter-signed by TÜV, BV, SGS, Lloyd's Register or your own inspector.
- NACE MR0175 / ISO 15156-3 and PED 2014/68/EU documentation where the end use requires it.
Third-party inspectors and customer QA representatives are welcome at the works. We ship the same material under the designations NW0276, UNS N10276, W.Nr. 2.4819, NiMo16Cr15W and Alloy C-276 where a specification calls the grade by a different name.
How to request an NW0276 quotation
Send a drawing or a dimensional sketch to sales@steelforgepieces.com. Quotations are normally returned within one working day when the following points are supplied.
- Grade and standard: NW0276, UNS N10276, Alloy C-276 or 2.4819, and which specification governs (ASTM B564, ASTM B462, ISO 9725, AMS 5750, or your own drawing).
- Product form: ring, disc, shaft, bar, flange, sleeve, tube sheet or custom shape.
- Dimensions: OD, ID and height for rings; diameter and length for bars and shafts; plus an estimated finished weight.
- Delivery condition: as-forged, solution annealed and pickled, rough machined, or finish machined.
- Certification: EN 10204 3.1 or 3.2, and which third party if 3.2.
- NDT requirements: UT acceptance class, PT requirements, and whether ASTM G28 intergranular testing is required.
- Sour service: state if NACE MR0175 / ISO 15156-3 applies, so we certify hardness against it.
- Quantity and required delivery date.
Lead time for NW0276 forgings is normally 35 to 60 days depending on size, billet availability and machining scope. Nickel alloy billet is not always on the shelf. Early notice on large sections shortens delivery more than anything else.
Frequently asked questions about NW0276
What is NW0276?
NW0276 is the Japanese Industrial Standard designation for wrought alloy C-276, a nickel–molybdenum–chromium–tungsten alloy. It is the same material as UNS N10276 and W.Nr. 2.4819. Nominal composition is 57% nickel, 15–17% molybdenum, 14.5–16.5% chromium, 3–4.5% tungsten and 4–7% iron, with carbon limited to 0.010% and silicon to 0.08%. It is used where a component must resist both oxidising and reducing corrosion, chlorides, and wet chlorine.
Is NW0276 the same as Hastelloy C-276?
Yes. They are the same chemistry under different names. NW0276 is the JIS designation, N10276 is the UNS number, 2.4819 is the German material number, and Hastelloy® C-276 is the brand name under which Haynes International sells it. Material produced by Jiangyin Jiangnan Metal Co., Ltd. is correctly described as NW0276 / UNS N10276 / Alloy C-276, and is not branded material.
What is the UNS number for NW0276?
The UNS number for NW0276 is N10276. Related designations are W.Nr. 2.4819, DIN NiMo16Cr15W, ISO NiMo16Cr15Fe6W4, GB/T 15007 NS3304 and AMS 5750.
What is the chemical composition of NW0276?
Nickel balance (about 57%), molybdenum 15.0–17.0%, chromium 14.5–16.5%, tungsten 3.0–4.5%, iron 4.0–7.0%, cobalt 2.5% max, manganese 1.0% max, vanadium 0.35% max, phosphorus 0.04% max, sulphur 0.03% max, carbon 0.010% max and silicon 0.08% max. The very low carbon and silicon are deliberate: they suppress grain-boundary precipitation so the alloy can be used as welded.
What are the mechanical properties of NW0276?
In the solution-annealed condition, minimum tensile strength is 690 MPa (100 ksi), minimum 0.2% proof stress is 275 MPa to JIS and EN or 283 MPa (41 ksi) to ASTM B564 and B574, and minimum elongation is 40%. Hardness is typically 85–95 HRB and capped at 100 HRB for NACE sour service. Modulus of elasticity is 205 GPa.
What is the density of NW0276?
The density of NW0276 is 8.89 g/cm³, or 0.321 lb/in³. Its melting range is 1325–1370 °C and its thermal conductivity at 21 °C is 10.2 W/m·K.
Can NW0276 be hardened by heat treatment?
No. NW0276 is solid-solution strengthened and cannot be age hardened or precipitation hardened. Higher strength can only be obtained by cold work, and cold work beyond roughly 7% outer-fibre elongation must be followed by a re-anneal to restore corrosion resistance. Stress-relief cycles are not effective and should not be used. A full solution anneal is required instead.
What is the correct heat treatment for NW0276?
Solution anneal at 1121–1160 °C (2050–2120 °F), hold 10 to 30 minutes depending on section thickness or one hour per 25 mm, then water quench. Rapid air cooling is acceptable only for sections thinner than about 10 mm. The quench must be fast enough to pass through the 1090–650 °C band without precipitating mu phase, P phase or M6C carbides, which would destroy corrosion resistance.
What is the forging temperature range for NW0276?
Start forging at a maximum of 1232 °C (2250 °F) and finish above 954 °C (1750 °F). The window is narrow and the alloy is sensitive to strain rate, so moderate reductions with frequent reheating give the best result. Every forging must be re-annealed and water quenched after hot working to restore optimum corrosion resistance and ductility.
Is NW0276 weldable, and does it need post-weld heat treatment?
Yes, it welds readily by GTAW, GMAW, SMAW and submerged arc, using ERNiCrMo-4 wire (AWS A5.14) or ENiCrMo-4 covered electrodes (AWS A5.11). Because carbon is held to 0.010% and silicon to 0.08%, the heat-affected zone does not sensitise, so NW0276 is normally acceptable in the as-welded condition without a post-weld solution anneal. This is one of its main practical advantages over the older alloy C.
What corrosive media does NW0276 resist?
Wet chlorine gas, hypochlorite and chlorine dioxide; ferric and cupric chlorides; seawater and brines; sulphuric acid across the concentration range at low to moderate temperature; hydrochloric acid at low to medium concentration and temperature; phosphoric acid; formic and acetic acid and acetic anhydride; and sour gas containing H2S. It is less suited to hot concentrated nitric acid, where a higher-chromium grade such as Alloy C-22, Alloy 59 or Alloy 690 is the better choice.
What is the PREN of NW0276?
Using PREN = %Cr + 3.3(%Mo + 0.5%W) and mid-range chemistry, NW0276 gives approximately 74. For comparison, 316L is around 24, super duplex 2507 around 42 and Alloy C-22 around 68. Reported critical pitting temperatures in ASTM G48 ferric chloride testing exceed 85 °C.
What is the maximum service temperature of NW0276?
In dry oxidising atmospheres NW0276 is stable to about 1038 °C (1900 °F). For pressure-retaining construction, ASME Section VIII Division 1 allowable stresses are published up to 677 °C (1250 °F), while Section III and Section VIII Division 2 are limited to 427 °C (800 °F). In wet corrosive service the practical limit is set by the process chemistry, not by the metal.
Which standards cover NW0276 forgings?
ASTM B564 / ASME SB-564 for forgings, ASTM B462 / ASME SB-462 for forged flanges, fittings and valve parts, ASTM B574 / ASME SB-574 for rod and bar, ISO 9725 for forgings, ISO 9723 for rod and bar, AMS 5750 for bar and forging stock, and JIS H4551 to H4554. VdTÜV Werkstoffblatt 400 covers European pressure-equipment approval, and NACE MR0175 / ISO 15156-3 covers sour service.
Is NW0276 approved for sour service?
Yes. UNS N10276 is listed in NACE MR0175 / ISO 15156-3 for use in H2S-bearing oilfield environments. The material must be supplied in the solution-annealed condition with hardness at or below 100 HRB. State the requirement on the enquiry and we will certify the hardness against it on the mill certificate.
What is the difference between NW0276 and Alloy 625?
NW0276 carries 15–17% molybdenum and 3–4.5% tungsten with no niobium, which makes it markedly better in reducing acids, chlorides and wet chlorine, with a PREN near 74. Alloy 625 has 8–10% molybdenum plus 3.15–4.15% niobium, giving it higher strength (414 MPa minimum yield against 275 MPa) but a lower PREN near 51. Choose NW0276 when corrosion drives the design and Alloy 625 when strength does.
Who supplies NW0276 open-die forgings in China?
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory at No. 1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province, China, producing NW0276 forged rings, seamless rolled rings, discs, shafts, flanges, bars, sleeves and tube sheets to drawing. Enquiries go to sales@steelforgepieces.com or 0086-189-2135-9659. Jiangyin is in the Yangtze River Delta, about two hours from Shanghai port, which keeps freight cost down on heavy forgings.
What certificates are supplied with NW0276 forgings?
EN 10204 3.1 mill test certificates are standard, covering chemical analysis, mechanical test results, heat-treatment charts, NDT reports and dimensional records. EN 10204 3.2 certificates counter-signed by TÜV, BV, SGS or Lloyd's Register are available on request, as are ASTM G28 intergranular corrosion test reports, NACE MR0175 / ISO 15156 documentation and PED 2014/68/EU compliance.
Is there a minimum order quantity for NW0276 forgings?
There is no fixed minimum quantity and single prototype pieces are accepted, although the price per piece falls with quantity because billet, tooling, set-up and furnace charges are shared. Lead time is normally 35 to 60 days depending on size, billet availability and machining scope.
About the manufacturer
Jiangyin Jiangnan Metal Co., Ltd. is an open-die forging factory in Jiangyin, Jiangsu Province, China. We produce forged rings, seamless rolled rings, discs, shafts, flanges, bars, sleeves and bushings in carbon steel, alloy steel, tool steel, stainless steel and nickel-based alloys, including NW0276 and the wider nickel alloy range. Work is made to customer drawing and certified to EN 10204 3.1 or 3.2. The plant runs 1, 3, 5 and 9 tonne forging hammers, a 5000 tonne hydraulic press and 3 m and 6 m ring-rolling mills, with in-house heat treatment, machining and a test laboratory covering tensile, impact, hardness, ultrasonic, magnetic particle and metallographic examination.
- CompanyJiangyin Jiangnan Metal Co., Ltd.
- BusinessOpen-die forging, seamless ring rolling, heat treatment, machining
- AddressNo. 1 Chengxiqiao Road, Zhouzhuang Town, Jiangyin City, Jiangsu Province 214423, China
- Telephone0086-189-2135-9659
- Emailsales@steelforgepieces.com
- Websitewww.steelforgepieces.com
- CertificationEN 10204 3.1 and 3.2 mill test certificates; third-party witness by TÜV, BV, SGS, Lloyd's Register
Data source and citation
The technical data on this page is published by Jiangyin Jiangnan Metal Co., Ltd. and may be quoted or reproduced with attribution. Suggested citation:
Jiangyin Jiangnan Metal Co., Ltd. (2026). NW0276 Forgings: JIS NW0276 / UNS N10276 / Alloy C-276 Technical Datasheet. Jiangyin, Jiangsu, China. https://www.steelforgepieces.com/Nickel-Alloy/NW0276.html
Page published . Last updated and technically reviewed by the metallurgical engineering team, Jiangyin Jiangnan Metal Co., Ltd. Chemistry checked against UNS N10276 and JIS NW0276 limits; thermal processing data checked against published Alloy C-276 mill practice.