1. Basic Information
- Grade: Hastelloy C22
- UNS: N06022
- W.Nr.: 2.4602
- Alloy Type: Nickel-Chromium-Molybdenum-Tungsten austenitic superalloy
- Key Characteristics:Excellent general corrosion resistance, superior pitting/crevice corrosion resistance, excellent weldability, and resistance to intergranular corrosion.
2. Chemical Composition (wt%, typical)
| Element | Composition |
|---|---|
| Nickel (Ni) | Balance |
| Chromium (Cr) | 20.0 – 22.5% |
| Molybdenum (Mo) | 12.5 – 14.5% |
| Tungsten (W) | 2.5 – 3.5% |
| Iron (Fe) | 2.0 – 6.0% |
| Cobalt (Co) | ≤ 2.5% |
| Carbon (C) | ≤ 0.015% |
| Manganese (Mn) | ≤ 0.50% |
| Silicon (Si) | ≤ 0.08% |
| Vanadium (V) | ≤ 0.35% |
3. Mechanical Properties (Annealed Condition)
- Tensile Strength: ≥ 760 MPa
- Yield Strength (0.2% offset): ≥ 380 MPa
- Elongation: ≥ 40%
- Hardness: ≤ HRC 33 / HB ≤ 210
- Modulus of Elasticity: ~205 GPa
4. Corrosion Resistance
- Outstanding resistance to oxidizing and reducing acids (H₂SO₄, HCl, HF, H₃PO₄).
- Excellent resistance to pitting, crevice corrosion, and chloride stress corrosion cracking (SCC).
- Superior performance in flue gas desulfurization (FGD) systems.
- Very low tendency toward intergranular corrosion after welding.
- Performs better than C276 in many aggressive oxidizing environments.
5. Physical Properties
- Density: 8.69 g/cm³
- Melting Range: 1366 – 1417 °C
- Thermal Expansion (20–100°C): ~11.4 × 10⁻⁶ /°C
- Thermal Conductivity: ~10.6 W/(m·K)
- Magnetism: Non-magnetic
6. Fabrication & Welding
- Heat Treatment: Solution anneal at 1120–1170°C, rapid cooling (water quench preferred).
- Welding: Excellent weldability.Recommended filler: ERNiCrMo-10
- No post-weld heat treatment required for corrosion resistance.
- Good formability in cold working conditions.
7. Typical Applications
- Chemical process industry: reactors, heat exchangers, piping
- Flue gas desulfurization (FGD) systems
- Waste incineration and pollution control equipment
- Pharmaceutical production equipment
- Seawater and brackish water handling systems
- Oil and gas production in aggressive environments
8. Short Description (for Post List Excerpt)
Hastelloy C22 (UNS N06022)
A premium Ni-Cr-Mo-W superalloy with exceptional resistance to pitting, crevice corrosion, and stress corrosion cracking.
Widely used in FGD, chemical processing, and harsh corrosive environments.
Excellent weldability with no post-weld heat treatment required.