Material Family

Nickel-Chromium-Molybdenum-Tungsten Superalloy (Wrought, Low-Carbon)

Represents an optimized, "third-generation" C-type alloy with enhanced versatility.

Common Designations

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

A premium-grade alloy for the most severe and mixed chemical services. "Hastelloy" is a trademark of Haynes International.

Chemical Composition (Typical wt.%)

Ni: ≥ 56.0 (Balance)
Cr: 20.0 - 22.5
Mo: 12.5 - 14.5
Fe: 2.0 - 6.0
W: 2.5 - 3.5
Co: ≤ 2.5
V: ≤ 0.35
C: ≤ 0.010
Si: ≤ 0.08

Higher Chromium (Cr) than C-276 improves resistance to oxidizing media. Balanced Mo & W provide stability in reducing conditions. Very Low C & Si prevent sensitization.

Mechanical Properties (Annealed Plate)

Tensile Strength (Rm): 690 - 827 MPa
Yield Strength (Rp0.2): 310 - 414 MPa
Elongation (A): 45 - 55%

High strength combined with excellent ductility and toughness.

Physical Properties

Density: 8.69 g/cm³
Melting Range: 1355 - 1395 °C

Slightly lower density than C-276 due to optimized chemistry.

Key Corrosion Resistance Attributes

• Outstanding resistance to pitting, crevice corrosion, and stress corrosion cracking.• Excellent resistance to both oxidizing and reducing media, including mixed acids (e.g., HNO₃ + HF).• Superior resistance to hot contaminated mineral acids, salts, and seawater.• Excellent performance in oxidizing chloride solutions (e.g., FeCl₃, CuCl₂).

Considered to have the broadest corrosion resistance of any commercially available wrought alloy, ideal for unpredictable or fluctuating process streams.

Key Standards (Plate)

ASTM B575 / ASME SB-575 (Grade UNS N06022), DIN 2.4602

Procured under the same ASTM standard as C-276, but to the N06022 composition.

Fabrication Note

Excellent weldability using matching filler metal (ERNiCrMo-10). Like C-276, it exhibits excellent as-welded corrosion resistance without requiring post-weld heat treatment.

The optimized chemistry further enhances the stability of the weld zone.

Form Availability

Plate, Sheet, Bar, Pipe, Tube, Fittings, Welding Wire

Available in standard mill forms for critical construction projects.

Typical Applications

• Chemical Process Industry: Reaction vessels, liners, heat exchangers for aggressive mixed acids.
• Flue Gas Desulfurization (FGD) Systems: Scrubber towers, fan housings, ducting.
• Pharmaceutical & Fine Chemical Synthesis Reactors.
• Industrial & Hazardous Waste Processing Equipment.
• Marine and Offshore Components exposed to chlorides.

The material of choice for critical components where reliability in the face of complex, aggressive chemistry is paramount.