High-performance alloy material for industrial engineering and critical application conditions.
1. Hastelloy C-22 Material Introduction
Hastelloy C-22 is a universal nickel-chromium-molybdenum-tungsten alloy, delivering superior overall corrosion resistance compared with other Ni-Cr-Mo alloys including Hastelloy C276, C4 and Alloy 625.
2. Chemical composition of Hastelloy C-22
| Alloy | Limit | Ni | Cr | Mo | Fe | W | Co | C | Mn | Si | V | P | S |
| Hastelloy C22 | Min | Bal | 14.5 | 15.0 | 4.0 | 3.0 | – | – | – | – | – | – | – |
| Max | 16.5 | 17.0 | 7.0 | 4.5 | 2.5 | 0.08 | 1.0 | 1.0 | 0.35 | 0.040 | 0.030 | ||
| Min | Bal | 20.0 | 12.5 | 2.0 | 2.5 | – | – | – | – | – | – | – | |
| Max | 22.5 | 14.5 | 6.0 | 3.5 | 2.5 | 0.015 | 0.5 | 0.08 | 0.35 | 0.020 | 0.020 |
3. Material characteristics
Hastelloy C-22 offers outstanding resistance to pitting, crevice corrosion and stress corrosion cracking. It performs excellently in oxidizing aqueous media such as wet chlorine, nitric acid and chloride-containing mixed oxidizing acids. Meanwhile, C-22 possesses balanced resistance to both reducing and oxidizing service environments, making it suitable for harsh corrosive conditions and multi-purpose production plants.
The alloy resists various aggressive chemical media including strong oxidants: ferric chloride, cupric chloride, chlorine, hot contaminated organic & inorganic solutions, formic acid, acetic acid, acetic anhydride, seawater and brine. It suppresses grain boundary precipitation within weld heat-affected zones, so welded components can serve in a wide range of chemical processing conditions.
Metallographic structure: Hastelloy C-22 has a face-centered cubic lattice structure.
4. Hastelloy C22 corrosion resistance
Hastelloy C-22 adapts to chemical processes containing both oxidizing and reducing media. Elevated chromium and molybdenum provide chloride corrosion resistance, while tungsten further enhances corrosion performance. It is one of few materials resistant to wet chlorine, hypochlorite and chlorine dioxide solutions, with remarkable tolerance to high-concentration chloride salt solutions such as ferric chloride and cupric chloride.
5. Hastelloy C22 application field
Hastelloy C-22 is widely used in chemical and petrochemical industries for equipment contacting chloride organics and catalytic systems. It is ideal for high-temperature environments contaminated by inorganic & organic mixed acids (formic acid, acetic acid) and seawater corrosion conditions.
