Hastelloy C-22丨UNS N06022

Hastelloy C-22 is a premier Ni-Cr-Mo-W alloy designed to resist a wide range of severe corrosive environments. It provides exceptional resistance to pitting, crevice corrosion, and stress corrosion cracking. With a higher chromium content than C-276, it offers superior protection in oxidizing media (such as nitric acid and ferric salts) while maintaining excellent resistance to reducing environments.

The alloy’s chemistry is optimized for thermal stability, preventing the formation of grain-boundary precipitates in the weld heat-affected zone. This makes it suitable for most chemical process applications in the as-welded condition. C-22 resists the formation of aqueous corrosion in various media, including oxidizing organics, wet chlorine, formic and acetic acids, and brine solutions.

Hastelloy C-22丨UNS N06022丨W.Nr. 2.4602

Applications of Hastelloy C-22:

Hastelloy C-22 is the “workhorse” alloy for the most demanding chemical and pharmaceutical environments:

  • Chemical Processing: Chlorination systems, sulfur dioxide scrubbers, and pulp and paper bleach plants.

  • Pharmaceutical: Vessel reactors, agitators, and piping systems where high purity and corrosion resistance are vital.

  • Waste Treatment: Hazardous waste incineration and wastewater treatment components.

  • Power Industry: Flue gas desulfurization (FGD) systems.

  • Marine & Oil: Sour gas environments and seawater cooling systems.

Normal product forms: Pipe, tube, sheet, strip, plate, fittings, round bar, flat bar, forging, hexagon, and wire.

Specifications/Standard: ASTM B575 / ASME SB575, ASTM B574 / ASME SB574, ASTM B619/B622 / ASME SB619/SB622, NACE MR0175

Chemical Composition:
  • Nickel (Ni): 51.0 – 63.5% (Balance)
  • Chromium (Cr): 20.0 – 22.5%
  • Molybdenum (Mo): 12.5 – 14.5%
  • Iron (Fe): 2.0 – 6.0%
  • Tungsten (W): 2.5 – 3.5%
  • Cobalt (Co): 2.5% max
  • Manganese (Mn): ≤0.50%
  • Vanadium (V): ≤0.35%
  • Silicon (Si): ≤0.08%
  • Carbon (C): ≤0.015%
  • Phosphorus (P): ≤0.02%
  • Sulfur (S): ≤0.02%

Physical Constants and Thermal Properties

  • Density: 8.69 g/cm³ (0.314 lb/in³)
  • Melting Range: 1357°C – 1399°C (2475°F – 2550°F)
  • Specific Heat Capacity: 414 J/(kg·K) at 20°C
  • Thermal Conductivity: * 10.1 W/(m·K) at 20°C
  • 20.1 W/(m·K) at 600°C
  • Modulus of Elasticity: 206 GPa at 20°C
  • Electrical Resistivity: 1.14 µΩ·m at 20°C

Mechanical Property:

  • Tensile Strength: ≥690 MPa (100 ksi)

  • Yield Strength: ≥310 MPa (45 ksi)

  • Elongation: ≥45%

  • Hardness: ≤100HRB