Hastelloy C276 vs C22: Corrosion Resistance, Composition, and Applications

 

When selecting materials for aggressive chemical or seawater environments, engineers often compare Hastelloy C276 and Hastelloy C22.

Both are nickel-chromium-molybdenum superalloys designed for extreme corrosion resistance. However, their performance differs significantly in chloride-rich environments.

The key reason is chromium content.

Hastelloy C22 contains about 22% chromium, much higher than C276 (~15.5%), which gives C22 superior resistance to pitting, crevice corrosion, and chloride stress corrosion cracking.

Chemical Composition Difference

 

Higher chromium is the main reason C22 performs better in seawater and wet chlorine conditions.

Corrosion Resistance Comparison

Choose C22 if your environment includes:

• Seawater systems
• Offshore platforms
• Wet chlorine gas
• High chloride process lines
• Pollution control equipment

Choose C276 for:

• Heat exchangers
• Chemical reactors
• General acid environments
• Projects with budget sensitivity

Mechanical Properties

Both alloys have very similar strength and fabrication performance:

• Excellent weldability
• Available as plates, sheets, pipes, tubes, and coils
• Suitable for heat exchangers and chemical equipment manufacturing

Selection is usually based on corrosion behavior, not strength.

Practical Selection Rule

If chlorides are present → C22
For general corrosion resistance → C276 is sufficient and more economical

Typical Industrial Applications

Conclusion

Although both Hastelloy grades are high-performance corrosion-resistant alloys, C22 is designed for the harshest chloride environments, while C276 offers excellent all-round corrosion resistance at a lower cost.

Understanding this difference helps engineers choose the most cost-effective and durable material for their projects.

Industrial material source:
https://www.maxwell-steel.com/

Nickel alloy plates, sheets, pipes, tubes, and custom sizes for chemical and heat-exchange equipment.