Austenitic Corrosion Resistant Hastelloy C-22 Nickel Alloy For Harsh Chemical Processing
Hastelloy C-22 is a fully austenitic, advanced corrosion-resistant nickel-chromium-molybdenum-tungsten alloy. It offers outstanding resistance to both uniform corrosion in oxidizing media and localized attack (pitting, crevice corrosion) in reducing environments.
Unlike standard alloys, C-22 provides exceptional resistance to stress corrosion cracking (SCC), intergranular attack, and weld heat-affected zone (HAZ) corrosion. This makes it the preferred material for harsh chemical processing, flue gas desulfurization (FGD), and marine systems where other alloys fail.
Hastelloy C-22's unique balance of chromium (oxidizing resistance) and molybdenum + tungsten (reducing resistance) delivers its "universal" corrosion resistance.
| Element | Content (%) | Role |
|---|---|---|
| Nickel (Ni) | Balance | Base metal provides austenitic stability |
| Chromium (Cr) | 20.0 - 22.0 | Excellent resistance to oxidizing acids & salts |
| Molybdenum (Mo) | 12.5 - 14.5 | High resistance to reducing acids (HCl, H₂SO₄) & pitting |
| Tungsten (W) | 2.5 - 3.5 | Enhances resistance to reducing conditions & crevice corrosion |
| Iron (Fe) | 2.0 - 6.0 max | Controlled to prevent unwanted phase formation |
| Cobalt (Co) | 2.5 max | Low for nuclear applications |
| Vanadium (V) | 0.35 max | Grain refiner |
| Carbon (C) | 0.015 max | Very low to prevent carbide precipitation |
| Manganese (Mn), Silicon (Si) | 0.50 / 0.08 max | Trace elements |
This unique composition allows Alloy 22 to perform in mixed acid environments (e.g., nitric + hydrochloric) that rapidly attack standard stainless steels.
| Property | Metric (MPa) | Imperial (KSI) |
|---|---|---|
| Tensile Strength (min) | 690 MPa | 100 KSI |
| Yield Strength 0.2% Offset (min) | 310 MPa | 45 KSI |
| Elongation (min) | 45% | 45% |
| Hardness | ≤ 100 HRB | - |
| Density | 8.69 g/cm³ | 0.314 lb/in³ |
| Melting Range | 1350 - 1400 °C | 2460 - 2550 °F |
We supply all standard forms of Hastelloy C-22 in compliance with international standards. Custom dimensions (cut-to-length, machined, or forged) are available.
| Product Form | Dimensions | Key Specifications (ASTM / ASME / ISO) |
|---|---|---|
| Sheet / Plate / Strip | Thickness: 0.5mm - 50mm | ASTM B575 / B906, ASME SB575, ISO 6208 |
| Round Bar / Flat Bar / Wire | Diameter: 6mm - 300mm | ASTM B574 / B462, ASME SB574, ISO 9724, DIN 17752 |
| Seamless Pipe / Tube | OD: 6mm - 219mm | ASTM B622 / B829, ASME SB622, ISO 6207, DIN 17751 |
| Welded Pipe / Tube | OD: up to 914mm | ASTM B619 / B775, ASME SB619, ASTM B626 (welded tube) |
| Fittings (Elbow, Tee, Reducer) | All schedule types | ASTM B366 / ASME SB366 |
| Forgings | Custom sizes | ASTM B564, ASME SB564, DIN 17754 |
| Welding Wire / Electrode | Diameter: 1.2mm - 4.0mm | AWS A5.14 (ERNiCrMo-10), AWS A5.11 (ENiCrMo-10) |
Available Standards: Also available to DIN (17750, 17751, 17752), VdTÜV Werkstoffblatt 479, and ISO 6207/9723.
- Chemical & Petrochemical Processing (reactors, heat exchangers)
- Pollution Control (Flue Gas Desulfurization - FGD scrubbers, ducts, stacks)
- Pharmaceutical & Food Processing
- Marine Engineering (offshore platforms, saltwater cooling systems)
- Waste-to-Energy & Power Generation (boiler tubes, ducting)
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