Hastelloy C276 or Alloy C-276, this nickel-chromium-molybdenum-tungsten material serves as a baseline defensive shield in severe processing environments. HT PIPE is a leading stockist and global exporter with over 16 years of expertise in international trade. We supply pipes, plates, round bars, and a comprehensive range of pipe fittings, flanges, and valves. Contact us now for free quotes and personalized product information.
Hastelloy C276 Chemical Composition
| Grade | C | Mn | Si | S | Co | Ni | Cr | Fe | Mo | P |
| C276 | 0.010 max | 1.00 max | 0.08 max | 0.03 max | 2.50 max | 50.99 min* | 14.50 – 16.50 | 4.00 – 7.00 | 15.00 – 17.00 | 0.04 max |
2.4819 Alloy C276 Mechanical Properties
| Grade | Density | Melting Point | Tensile Strength | Yield Strength (0.2%Offset) | Elongation |
| C276 | 8.89 G/Cm33 | 1370 °C (2500 °F) | Psi – 1,15,000 , MPa – 790 | Psi – 52,000 , MPa – 355 | 40 |
Core Product Forms and Engineering Specifications
To accommodate diverse piping, structural, and mechanical designs, UNS N10276 is manufactured in several standard raw and semi-finished formats. Selecting the correct form depends on your system's pressure ratings, structural requirements, and geometric constraints.
1. Heavy Plate and Sheet Stock
Specifications: ASTM B575, ASME SB575
Application: Ideal for fabricating heavy-duty reaction vessels, large storage tanks, heat exchanger shell linings, and Flue Gas Desulfurization (FGD) scrubber housings. Thick plates maintain excellent mechanical stability under high hydrostatic loads.
2. Seamless and Welded Piping / Tubing
Specifications: ASTM B622 (Seamless), ASTM B619 / B626 (Welded)
Application: Seamless lines are the standard for high-pressure, high-temperature (HPHT) chemical transmission lines and deep downhole oil and gas production tubing. Welded variants provide a cost-effective alternative for lower-pressure utility or transfer loops.
3. Round Bars and Forgings
Specifications: ASTM B574 (Bar), ASTM B564 (Forgings)
Application: Forged blanks and round stock are heavily machined to produce heavy-duty valve stems, high-stress fasteners, pump impellers, and custom instrument fittings.
4. Pipe Fittings and Flanges
Specifications: ASTM B366 (Fittings), ASTM B564 (Flanges)
Application: Essential for constructing fully sealed, continuous-run piping networks. Standard components include long-radius elbows, equal tees, concentric reducers, and weld-neck flanges ranging from Class 150 to Class 2500 ratings.
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Fabrication, Welding, and Machining Considerations
Working with UNS N10276 requires specialized fabrication knowledge. Due to its high alloy content, it does not behave like standard structural carbon or stainless steels.
Welding Strategy
UNS N10276 is readily weldable using Gas Tungsten Arc Welding (GTAW/TIG), Gas Metal Arc Welding (GMAW/MIG), or Shielded Metal Arc Welding (SMAW/Stick).
Filler Metal: Use matching composition consumables, typically classified under AWS A5.14 ERNiCrMo-4 or AWS A5.11 ENiCrMo-4.
Pro Tip: Avoid oxyacetylene or submerged arc welding (SAW) processes when the component is intended for severe corrosion service, as these methods can introduce impurities or alter the weldment's microstructural integrity.
Machining and Forming
Like most nickel-base superalloys, UNS N10276 work-hardens rapidly during machining. To optimize production runs and extend tool life:
Use rigid, heavy-duty machining setups with sharp, carbide-tipped tooling.
Maintain positive, continuous feeds to prevent the tool from riding on the material and glazing the work surface.
Utilize heavy, high-lubricity coolants to manage heat accumulation at the cutting zone.
Typical Applications
Chemical and Petrochemical: Acetic, sulfuric, and phosphoric acid plants, cracked gas quenching systems in ethylene plants and organic synthesis processes containing chlorides.
Marine Engineering and Seawater Desalination: Seawater cooling piping systems, preheaters, pumps, and piping in seawater desalination plants; and high-pressure seawater systems on ships.
Flue Gas Desulfurization (FGD) Systems: Wet areas most susceptible to corrosion, such as the absorber spray layer, demister, and outlet flue.
Paper Industry: Equipment and piping in the pulp bleaching process (ClO₂ environment).
Pharmaceutical and Food Industries: Demanding process steps requiring extreme cleanliness and corrosion resistance.
Environmental Protection: Wastewater treatment, particularly for industrial wastewater containing high levels of chlorides, sulfides, or acidic components.
