Discover the latest trends and innovations in the nickel alloy industry. We provide expert insights and in-depth analysis on the newest developments in nickel alloys.
Hastelloy C22 pipe is a high-performance nickel-chromium-molybdenum alloy product widely used in severe chemical processing environments. Known for its outstanding resistance to both oxidizing and reducing chemicals, Hastelloy C22 pipe provides superior performance in a wide range of corrosive media, including strong acids, chlorine compounds, and hot contaminated solutions. It is often selected over similar alloys such as C276 or Alloy 625 when maximum versatility and chemical stability are required.
Hastelloy C22 (UNS N06022 / W. Nr. 2.4602) contains a carefully balanced composition of nickel, chromium, molybdenum, tungsten, and iron. This unique chemistry ensures a protective passive film that resists attack from both oxidizing and reducing agents. The typical composition includes approximately 56% nickel, 22% chromium, 13% molybdenum, 3% tungsten, and small amounts of iron and cobalt. This alloy design offers exceptional resistance to a wide variety of aggressive chemicals.
Hastelloy C22 pipe provides excellent corrosion resistance in oxidizing and reducing conditions alike. It resists strong oxidizers such as nitric acid, ferric chloride, and cupric sulfate, as well as reducing agents including hydrochloric and sulfuric acids. The alloy also demonstrates strong resistance to pitting, crevice corrosion, and stress-corrosion cracking, even in hot and contaminated environments. This makes C22 one of the most universally corrosion-resistant nickel alloys available today.
In addition to corrosion resistance, Hastelloy C22 pipe offers excellent mechanical strength and toughness. It maintains structural integrity across a wide temperature range, from cryogenic conditions to over 1100°C. The alloy’s ductility and toughness make it suitable for both seamless and welded pipe manufacturing, allowing for easy fabrication and installation in chemical process systems.
Due to its versatility and superior resistance to mixed chemical environments, Hastelloy C22 pipe is used across multiple industries. Common applications include:
• Chemical process piping systems
• Heat exchangers and condensers
• Reactor vessels and scrubbers
• Waste treatment and pollution control equipment
• Marine exhaust and flue gas cleaning systems
Hastelloy C22 can be easily fabricated using standard forming, machining, and welding techniques. It is compatible with gas tungsten arc welding (GTAW), gas metal arc welding (GMAW), and shielded metal arc welding (SMAW). The alloy’s microstructure minimizes the risk of sensitization, ensuring consistent corrosion resistance across welded joints. Post-weld heat treatment is generally not required under normal conditions.
Hastelloy C22 pipe is available in both seamless and welded forms, depending on application requirements. Common standards include:
• ASTM B622 – Seamless nickel and nickel-cobalt alloy pipe and tube
• ASTM B619 – Welded nickel and nickel-cobalt alloy pipe
• ASTM B626 – Welded tube with filler metal
• ASME SB619 / SB622 – Pressure vessel grade equivalents
| Property | Hastelloy C22 | Hastelloy C276 | Inconel 625 |
|---|---|---|---|
| Main Alloying Elements | Ni, Cr, Mo, W, Fe | Ni, Mo, Cr, Fe, W | Ni, Cr, Mo, Nb |
| Corrosion Resistance | Excellent in oxidizing & reducing media | Excellent, especially in reducing conditions | Good, mainly in oxidizing media |
| Pitting Resistance | Superior | High | Moderate |
| Fabrication | Excellent | Excellent | Excellent |
| Cost | Higher | High | Moderate |
• Outstanding resistance to both oxidizing and reducing chemicals
• Excellent weldability and formability
• Strong resistance to localized corrosion
• High thermal stability and mechanical strength
• Suitable for demanding chemical and industrial service environments
In demanding chemical environments, Hastelloy C22 pipe offers unmatched versatility and long-term performance. Its combination of corrosion resistance, mechanical strength, and fabricability make it a preferred material for modern chemical processing systems where reliability and safety are critical.
