As demand for ultra-corrosion-resistant materials surges in 2026—driven by green hydrogen production, chemical processing, and offshore energy—understanding how Hastelloy C-276 is manufactured is crucial for engineers and procurement specialists. This nickel-based alloy's exceptional performance stems from precise control at every production stage, starting from carefully selected raw elements.
Hastelloy C-276 (UNS N10276) is a nickel-molybdenum-chromium alloy with tungsten additions, designed for extreme environments. Its balanced composition ensures outstanding resistance to pitting, crevice corrosion, and stress corrosion cracking.
Key elemental breakdown:
Element | Percentage (%) | Role in Alloy |
Nickel (Ni) | Balance (~57%) | Base metal; provides ductility and resistance to reducing environments |
Molybdenum (Mo) | 15.0 - 17.0 | Enhances resistance to pitting and crevice corrosion in reducing acids |
Chromium (Cr) | 14.5 - 16.5 | Improves oxidation resistance and passivity in oxidizing media |
Tungsten (W) | 3.0 - 4.5 | Boosts strength and resistance to localized corrosion |
Iron (Fe) | 4.0 - 7.0 | Cost-effective filler; controlled to minimize deleterious effects |
Cobalt (Co) | ≤2.5 | Minor addition for stability |
Others (C, Si, etc.) | Very low | Strictly limited to prevent carbide formation and embrittlement |
Low carbon and silicon levels are critical to maintain weldability and long-term stability.
Producing Hastelloy C-276 requires advanced techniques to achieve high purity and homogeneous microstructure. The process typically follows these stages:
Raw Material Selection and PreparationHigh-purity elemental metals (nickel pellets, molybdenum lumps, chromium flakes, tungsten powder) are sourced and precisely weighed. Impurities are minimized from the start, as even trace elements can compromise corrosion resistance.
Primary Melting: Vacuum Induction Melting (VIM)The charge is melted in a vacuum induction furnace to prevent oxidation and gas absorption. Temperatures reach ~1500-1600°C. VIM ensures excellent chemical homogeneity and removes volatile impurities. For critical applications, this is often followed by Electroslag Remelting (ESR) or Vacuum Arc Remelting (VAR) for further refinement.
Casting into IngotsThe molten alloy is poured into molds under vacuum or inert atmosphere, forming large ingots. Controlled solidification prevents segregation of heavy elements like molybdenum and tungsten.
Hot Working: Forging and RollingIngots are heated to 1100-1200°C and forged, hot-rolled, or extruded into billets, bars, plates, or sheets. Hastelloy C-276 work-hardens quickly, so intermediate reheating is often required.
Cold Working and FormingFor pipes, tubes, wires, and thin sheets, cold rolling, drawing, or pilgering is used. Annealing between passes prevents excessive hardening. The alloy's good ductility allows complex forming like deep drawing or spinning.
Solution Annealing and Rapid CoolingFinal heat treatment at 1121°C (2050°F) dissolves precipitates and optimizes microstructure. Rapid quenching (water or air) locks in the corrosion-resistant state. This step is essential for restoring ductility after working and maximizing performance.
Finishing and Quality ControlProducts undergo pickling, machining, testing (ultrasonic, corrosion tests per ASTM standards), and certification. Full traceability from raw materials to finished product is maintained.
In applications like electrolyzers for green hydrogen or acidic chemical reactors, any microstructural defect can lead to premature failure. Advanced melting techniques (VIM/ESR) deliver the purity needed for emerging demands, outperforming lesser alloys in lifecycle cost and reliability.
As a professional manufacturer and supplier of Hastelloy C-276 plates, pipes, fittings, and custom components, we adhere to strict processes with complete certifications (ASTM B564/B574/B575). Contact us today for quotations, samples, or technical support on your 2026 projects.
