| UNS Designation | N10276 | Melting Range | 1323–1371 °C |
| Werkstoff Nr. | 2.4819 | Density | 8.89 g/cm³ |
| Nickel | Bal. (57% min) | Tensile Strength | 690 MPa min |
| Molybdenum | 15.0–17.0% | Yield Strength | 283 MPa min |
| Chromium | 14.5–16.5% | Elongation | 40% min |
| Tungsten | 3.0–4.5% | PREN (approx) | 65–70 |
| Iron | 4.0–7.0% | Max Service Temp | ~1040 °C (oxidizing) |
| Magnetic? | Non-magnetic | Filler Metal | ERNiCrMo-4 |
C276's composition is dominated by nickel with 15–17% molybdenum, 14.5–16.5% chromium, 3–4.5% tungsten, and 4–7% iron—deliberately low in carbon (≤0.01%) and silicon (≤0.08%) to prevent weld HAZ precipitation.
| Element | Spec Range | Nominal | Metallurgical Role |
|---|---|---|---|
| Nickel (Ni) | Bal. (57 min) | ~61% | Matrix; SCC resistance; ductility |
| Molybdenum (Mo) | 15.0–17.0% | 16% | Reducing acid resistance; pitting resistance |
| Chromium (Cr) | 14.5–16.5% | 15.5% | Oxidizing acid passivation |
| Iron (Fe) | 4.0–7.0% | 5.5% | Cost control; matrix stability |
| Tungsten (W) | 3.0–4.5% | 3.75% | Solid-solution strengthening; crevice resistance |
| Cobalt (Co) | ≤ 2.5% | 1.0% | Impurity control |
| Manganese (Mn) | ≤ 1.0% | 0.5% | Deoxidation |
| Carbon (C) | ≤ 0.01% | 0.005% | Low carbon prevents carbide precipitation (key to weldability) |
| Silicon (Si) | ≤ 0.08% | 0.03% | Low silicon prevents intermetallic precipitation |
| Vanadium (V) | ≤ 0.35% | 0.15% | Micro-alloying |
| Phosphorus (P) | ≤ 0.04% | 0.01% | Impurity control |
| Sulfur (S) | ≤ 0.03% | 0.005% | Impurity control |
The ultra-low carbon and silicon are what distinguish C276 from the original Hastelloy C and make it the weldable, as-deposited corrosion-resistant alloy used today. See the full breakdown in Hastelloy C276 Chemical Composition.
C276 offers high strength (690 MPa UTS, 283 MPa yield) with excellent ductility (40% elongation) at room temperature, and retains useful strength to 650 °C. It remains tough at cryogenic temperatures, qualifying it for LNG and cryogenic acid service.
| Property | Value | Notes |
|---|---|---|
| Tensile Strength (min) | 690 MPa (100 ksi) | Solution-annealed, room temp |
| Yield Strength (min, 0.2% offset) | 283 MPa (41 ksi) | High for a solid-solution alloy |
| Elongation (min) | 40% | Excellent ductility |
| Hardness (Brinell) | ~ 210 HB | Annealed |
| Elastic Modulus (20°C) | 205 GPa | Comparable to nickel alloys |
| Charpy Impact (RT) | > 250 J | Very tough; no ductile-brittle transition |
| Charpy Impact (-196°C) | > 100 J | Cryogenic-qualified |
For elevated-temperature tensile data and creep rupture curves, see Hastelloy C276 Mechanical Properties.
C276 is the benchmark alloy for uniform corrosion in mixed oxidizing and reducing acid environments. It resists hydrochloric acid at all concentrations up to the boiling point (dilute), sulfuric acid up to 50% at boiling, wet chlorine gas, hypochlorite, organic acids, and chloride pitting (PREN ~65–70).
It is not indestructible—it can be attacked by very hot concentrated HCl, ferric chloride at high temperature, and strongly oxidizing nitric acid above 40%—but it covers a broader corrosion envelope than any other single alloy.
| Media | Concentration | Temp | Corrosion Rate | Rating |
|---|---|---|---|---|
| Hydrochloric acid | 10% | Boiling | 0.08 mm/yr | Excellent |
| Hydrochloric acid | 37% | 60°C | 0.15 mm/yr | Good |
| Sulfuric acid | 50% | Boiling | 0.20 mm/yr | Good |
| Sulfuric acid | 98% | 70°C | 0.50 mm/yr | Marginal |
| Wet chlorine gas | Saturated | 80°C | < 0.02 mm/yr | Excellent |
| Ferric chloride | 10% + 6% FeCl₃ | 50°C | 0.00 mm/yr (no pitting) | Excellent |
| Formic acid | 88% | Boiling | 0.05 mm/yr | Excellent |
| Nitric acid | 65% | Boiling | 5.5 mm/yr | Poor (not recommended) |
The PREN of ~65–70 places C276 far above 316L (23–25), Alloy 20 (25–28), 904L (35), and Inconel 625 (48–52), making it effectively immune to chloride pitting in nearly all practical service conditions. For full isocorrosion curves and mechanism analysis, see Hastelloy C276 Corrosion Resistance.
C276 is suitable for continuous service up to ~1040 °C in oxidizing atmospheres and for sustained stressed service up to ~760 °C. Above this range, carbide and intermetallic precipitation (mu phase) reduce corrosion resistance and ductility. At the cold end, the alloy remains tough to -196 °C with Charpy impact energy above 100 J.
| Temperature Range | Performance | Application Examples |
|---|---|---|
| -196 to 0°C | Full toughness retained; no ductile-brittle transition | LNG exchangers, cryogenic acid service |
| 0 to 200°C | Peak corrosion resistance; design envelope for most acid service | Chemical reactors, FGD scrubbers |
| 200 to 650°C | Excellent; no phase instability | Heat exchangers, superheater supports |
| 650 to 760°C | Good; monitor for long-term mu-phase precipitation | Furnace internals, reformer components |
| 760 to 1040°C | Marginal; oxidation resistance good but intermetallics form | Short-term / intermittent only |
| > 1040°C | Not recommended; rapid scaling and creep | None |
For detailed oxidation rate data and creep rupture curves, see Hastelloy C276 Temperature Limits.
C276 is readily welded with GTAW, GMAW, and SMAW using matching ERNiCrMo-4 filler metal. The low-carbon chemistry prevents weld HAZ sensitization, so no post-weld solution annealing is required for corrosion performance. Control heat input (0.5–1.5 kJ/mm) and interpass temperature (≤150°C) to avoid microfissuring.
| Process | Application | Filler Metal | Shielding Gas |
|---|---|---|---|
| GTAW (TIG) | Tubesheet, thin-wall pipe, precision | ERNiCrMo-4 | Argon (Ar + 2-5% H₂ optional) |
| GMAW (MIG) | Medium plate, shop fabrication | ERNiCrMo-4 | Ar + 2% CO₂ or Ar + He |
| SMAW (Stick) | Field welding, repair | ENiCrMo-4 | None (flux-covered) |
| SAW | Heavy plate, structural | ERNiCrMo-4 + neutral flux | Flux + Ar |
Key welding parameters: heat input 0.5–1.5 kJ/mm; interpass ≤ 150°C; stringer beads preferred over weave; argon ID purge mandatory for pipe root; no preheat required; no PWHT required for corrosion performance (may be specified for stress relief in sour service per NACE). Full procedure details in Hastelloy C276 Welding Guide.
C276 machines like all high-nickel alloys—it work-hardens rapidly, generates high cutting forces, and tends to weld to the tool (built-up edge). Use sharp carbide inserts, low surface speeds (30–60 m/min turning), positive feed, flood coolant, and rigid setups. Never let the tool "rub" without cutting—it will work-harden the surface and destroy the next pass.
| Operation | Speed (m/min) | Feed (mm/rev) | Tooling |
|---|---|---|---|
| Turning (rough) | 30–45 | 0.25–0.40 | Coated carbide, C-grade |
| Turning (finish) | 45–60 | 0.10–0.20 | Coated carbide, positive rake |
| Drilling | 10–20 | 0.05–0.15 | TiAlN-coated HSS or carbide |
| Milling | 25–40 | 0.03–0.08/tooth | Carbide end mill, coated |
| Tapping | 5–10 | — | Spiral-flute, lubricant essential |
For detailed machining strategies and troubleshooting, see Hastelloy C276 Machining Tips.
JN Alloy supplies the full range of C276 products—seamless and welded pipe/tube, plate/sheet/strip, bars, forgings, fittings, and flanges—to ASTM B619/B622/B626/B564/B366 with ASME code-stamped equivalents.
| Product Form | ASTM Standard | ASME | Size Range |
|---|---|---|---|
| Seamless Pipe & Tube | ASTM B622 | SB-622 | OD 6–324 mm, WT 1–25 mm |
| Welded Pipe (ERW) | ASTM B619 | SB-619 | OD 21–610 mm, WT 1.5–12 mm |
| Welded Tube | ASTM B626 | SB-626 | OD 6–152 mm, WT 0.5–6 mm |
| Plate, Sheet, Strip | ASTM B575 | SB-575 | Thickness 0.5–80 mm |
| Round Bars | ASTM B574 | SB-574 | Dia 6–300 mm |
| Forgings | ASTM B564 | SB-564 | Up to 2000 kg/piece |
| Welded Fittings | ASTM B366 | SB-366 | 1/2"–48", Sch 10S–80S |
| Flanges | ASTM B564 / ASME B16.5 | SB-564 | 1/2"–24", 150#–2500# |
For full standard references, see ASTM Standards for Hastelloy C276. For product inquiries, visit the Hastelloy C276 product page.
C276 is deployed in six major industrial sectors where the combination of strong acids, chlorides, and elevated temperatures defeats every stainless and most nickel alloys. The dominant users are chemical processing, FGD/power, pulp & paper, pharmaceutical, marine/offshore, and waste-to-energy.
| Industry | Typical Equipment | Why C276 |
|---|---|---|
| Chemical processing | Reactors, heat exchangers, columns, piping | Mixed acid + chloride universal resistance |
| FGD / power | Scrubber vessels, inlet ducts, mist eliminators, dampers | SO₂ + HCl + HF at 60–150°C |
| Pulp & paper | Bleach plant washers, digester internals, ClO₂ piping | Chlorine dioxide, caustic cycling |
| Pharmaceutical | API reactors, crystallizers, drying equipment | Acid purity, product contamination prevention |
| Marine / offshore | Seawater coolers, pump shafts, fasteners | Seawater pitting and crevice resistance |
| Waste-to-energy | Boiler tube cladding, scrubber internals | HCl + SO₂ + high temperature in flue gas |
For detailed case studies, see Common Applications of Hastelloy C276 and the industry-specific articles: Chemical Plants, Acid Service, FGD Systems, Pulp & Paper.
C276 is the premium choice when corrosion resistance is the overriding factor and cost is secondary. It outperforms Inconel 625 in reducing acids (HCl), outperforms Alloy 20 in mixed chloride/acid service, and vastly outperforms 904L and 825 across the board. It is typically 30–50% more expensive than 625 and 3–4× the cost of 904L, so it should be specified only where its unique corrosion envelope is actually needed.
| Criterion | C276 | Inconel 625 | Alloy 20 | 904L | Incoloy 825 |
|---|---|---|---|---|---|
| HCl Resistance | Excellent | Moderate | Poor | Poor | Poor |
| H₂SO™ Resistance | Excellent | Good | Excellent | Good | Good |
| Chloride SCC | Immune | Immune | Immune | Good | Good |
| PREN | 65–70 | 48–52 | 25–28 | 35 | 28–30 |
| Max Temp (oxidizing) | 1040°C | 980°C | 500°C | 400°C | 540°C |
| Relative Cost (vs 316L=1) | 4–5× | 3× | 2.5–3× | 2× | 2.5× |
| Weldability | Moderate | Good | Good | Good | Good |
| Best Application | Universal severe corrosion | Chloride + sour gas | Sulfuric acid | Phosphoric acid | Sour gas, acid |
For head-to-head analysis, see the comparison articles: C276 vs Inconel 625, C276 vs Alloy 20, C276 vs 904L, C276 vs Incoloy 825.
| Standard | Designation |
|---|---|
| UNS (USA) | N10276 |
| DIN / W.Nr. (Germany) | 2.4819 / NiMo16Cr15W (DIN 17740) |
| EN (Europe) | NiMo16Cr15W |
| AFNOR (France) | NC17D |
| BS (UK) | — |
| JIS (Japan) | NW 0276 |
| GB (China) | NS 334 |
| ISO | NiMo16Cr15W |
| Commercial Names | Hastelloy C276 / Nickelvac HC-276 / Nicrofer 4819 hMoW |
For the full cross-reference chart with all national standards, see Equivalent Grades of Hastelloy C276.
A complete C276 requisition must specify the UNS designation, product form, ASTM standard, condition (solution-annealed), dimensions, testing, and documentation. Work with a qualified supplier like JN Alloy with ASME code material, full EN 10204 3.1/3.2 MTCs, and proven nickel-alloy delivery history.
For the complete pipe selection guide, see How to Choose Hastelloy C276 Pipes. For product inquiries, visit the Hastelloy C276 product page or contact JN Alloy.
