Hastelloy Alloys C22 vs C276: Which Alloy Should You Choose?

Among the most reliable materials for industries that work in extremely corrosive conditions are hastelloy alloys. These nickel-based alloys are extensively utilized in chemical processing, pollution management, and maritime engineering because of their exceptional resistance to oxidising and reducing chemicals. Two of the most frequently stated grades among them are Hastelloy C22 and Hastelloy C276. However, how can you choose the one that best fits your application? To assist you in making an informed decision, this guide examines the two alloys, their characteristics, and practical uses.

What Are Hastelloy Alloys?

Nickel, chromium, molybdenum, and iron make up the majority of hastelloy alloys, which are metal materials that resist corrosion. Strong oxidisers, reducing agents, and chloride-rich conditions are only a few of the harsh circumstances that these alloys are made to endure.

Each grade in the family, such as Hastelloy alloy B-2, Hastelloy C276, and Hastelloy C22, is tailored for a particular environment.

SS 316 Stainless Steel: Composition and Properties

Superior resistance to saltwater and chlorides is one of SS 316’s primary characteristics.

resists corrosion in crevices and pitting.
holds up well in both hot and cold temperatures.
Surface that doesn’t react (clean and sanitary)

Hastelloy C22: Properties and Applications

The nickel, chromium, and molybdenum alloy Hastelloy C22 is made to be as resistant to oxidising conditions as possible.

Crucial Elements of Hastelloy C22:

strong defence against oxidising agents such as cupric and ferric chlorides.
robust protection against nitric acid and moist chlorine.
outstanding formability and weldability.

Typical Uses:

Equipment for chemical processing
Scrubbers for flue gases
Systems for bleaching pulp and paper

Conclusion: Because of its harmony of strength, toughness, and chloride resistance, SS 316 is the undisputed winner when comparing marine-grade stainless steel products.

Hastelloy C276: Properties and Applications

Among the Hastelloy family, Hastelloy C276 is regarded as the “workhorse.” It is well-known for its adaptability and works effectively in both reducing and oxidising environments.

Crucial Elements of Hastelloy C276:

exceptional resistance to a variety of strong substances.
remarkable resilience in conditions contaminated with chloride.
resistant to pitting and crevice attack, two types of localised corrosion.

Typical Uses:

Offshore machinery and marine engineering
Facilities for treating waste
Evaporators and heat exchangers

Other Hastelloy Materials: Alloy B-2

Besides C22 and C276, another important grade is Hastelloy alloy B-2:

Optimized for reducing environments such as hydrochloric acid.
Excellent resistance to hydrogen chloride gas and sulfuric acid.
Not suitable for oxidizing conditions (limited use in environments with ferric or cupric salts).

This is why material choice is so critical; each Hastelloy is designed for a differing kind of chemical exposure

Conclusion

Both Hastelloy C22 and Hastelloy C276 are high-performance nickel-based alloys that resist chemicals. Yet the choice will depend on one’s situation in the operation:

Use C22 for more oxidizing conditions.
Use C276 for more general, versatile protection.

In selecting Hastelloy between the two, application requirements and alternative grades such as Hastelloy alloy B-2 should always be considered if functioning in highly reducing conditions.

FAQ

What are Hastelloy alloys made of?

Hastelloy alloys are nickel-based materials with chromium, molybdenum, and iron. This composition gives them strength and corrosion resistance in aggressive environments.

Which is better: Hastelloy C22 or C276?

It depends on the application. Hastelloy C22 is best for oxidizing conditions, while C276 provides versatile protection in both oxidizing and reducing environments.

What is Hastelloy alloy B-2 used for?

Hastelloy alloy B-2 excels in reducing environments like hydrochloric acid and hydrogen chloride gas, but it is not recommended for oxidizing conditions

Why are Hastelloy alloys so popular?

They offer exceptional corrosion resistance, high strength, and durability in environments where stainless steel or other alloys would fail.

Where are Hastelloy C22 and C276 commonly used?

C22 is used in chemical processing, scrubbers, and bleaching systems. C276 is common in marine engineering, waste treatment, and heat exchangers.