Hastelloy is one of the most recognized names in the world of corrosion-resistant alloys. Known for exceptional performance in aggressive environments, Hastelloy alloys are widely used in industries such as chemical processing, marine, power generation, and pharmaceuticals. But not all Hastelloy grades are the same. Each variant offers unique properties tailored for specific applications and corrosion conditions.
In this article, we will explore the most commonly used Hastelloy grades and break down how they perform under different corrosive environments. Understanding these differences is key to selecting the right alloy for your project.
What Is Hastelloy?
Hastelloy is a trademarked name for a group of corrosion-resistant metal alloys primarily made from nickel, along with varying amounts of molybdenum, chromium, iron, and cobalt. These materials are designed to resist extreme chemical environments, including strong oxidizers, reducers, and acidic compounds.
Manufactured by Haynes International, Hastelloy alloys are known for their:
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Excellent corrosion resistance
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High mechanical strength
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Good weldability
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Longevity in harsh environments
Over the years, many grades of Hastelloy have been developed to serve different industrial demands.
Hastelloy C-276: The Industry Standard
One of the most widely used grades, Hastelloy C-276, offers outstanding resistance to a wide range of chemicals, including strong oxidizers, chloride-containing media, and wet chlorine gas.
Key corrosion resistance properties include:
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Excellent resistance to pitting, stress corrosion cracking, and crevice corrosion
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Superior performance in both oxidizing and reducing environments
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Suitable for sulfuric, hydrochloric, acetic, formic, and phosphoric acids
Hastelloy C-276 is a preferred material for reactors, heat exchangers, and pressure vessels in chemical processing plants.
Hastelloy C-22: For More Aggressive Media
If your application requires a higher level of corrosion resistance, Hastelloy C-22 is often the better choice. It contains more chromium and molybdenum than C-276, which improves its performance in oxidizing environments.
Corrosion advantages include:
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Enhanced resistance to oxidizing agents like nitric acid and ferric salts
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Excellent protection against wet chlorine and mixtures of nitric and hydrofluoric acids
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Better resistance to crevice corrosion than C-276
Due to its versatility, C-22 is often used in flue gas scrubbers, pulp and paper bleach plants, and pharmaceutical reactors.
Hastelloy X: Best for High-Temperature Environments
Hastelloy X is an iron-nickel-chromium-molybdenum alloy specifically designed for high-temperature applications, such as those in gas turbines, aircraft engines, and heat-treating equipment.
Corrosion and thermal performance highlights:
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Good oxidation resistance up to 2200°F (1204°C)
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Moderate resistance to carburization and nitriding
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Maintains strength and stability under extreme thermal stress
Although it is not as corrosion-resistant as the C-series, it excels where heat resistance is the top priority.
Hastelloy B-2 and B-3: Resistance to Reducing Environments
For applications involving strong reducing agents, Hastelloy B-2 and B-3 are recommended. These grades offer excellent resistance to hydrochloric acid at all concentrations and temperatures.
Comparing B-2 and B-3:
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B-3 has improved thermal stability and fabrication properties
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Both resist pitting and stress corrosion cracking in reducing environments
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Not recommended for oxidizing agents
These alloys are ideal for pickling operations, nuclear fuel reprocessing, and other industries dealing with pure or highly concentrated acids.
Why Corrosion Resistance Matters
Choosing the wrong alloy can result in premature failure, costly repairs, and safety hazards. Hastelloy alloys are engineered to withstand:
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Localized corrosion such as pitting and crevice attack
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Uniform corrosion in acidic or oxidizing media
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Stress corrosion cracking caused by mechanical and environmental factors
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Intergranular corrosion especially in welded or heat-affected zones
By selecting the right Hastelloy grade, you ensure the material integrity and performance of your system, especially in aggressive chemical environments.
Applications Across Industries
Hastelloy alloys are trusted in many critical sectors:
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Chemical processing: tanks, pipes, heat exchangers
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Marine: seawater systems, desalination units
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Aerospace: turbine components, combustion liners
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Pharmaceutical: reactor vessels, filters, process piping
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Nuclear: containment systems, waste handling
At sasaalloy, we offer a wide range of Hastelloy materials in bar, pipe, sheet, and plate forms—each sourced to meet international standards and client specifications.
How to Choose the Right Hastelloy Grade
When selecting the most suitable Hastelloy grade, consider the following:
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Chemical environment: type and concentration of acids or salts
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Temperature range: especially important for thermal applications
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Mechanical stress: including vibration, pressure, or flow
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Weldability and fabrication: depending on your production method
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Regulatory requirements: such as ASME, ASTM, or NACE compliance
If you are unsure, consult with material experts like the team at sasaalloy, who can assist in selecting the most appropriate alloy for your project.
Conclusion
Hastelloy is not a one-size-fits-all solution. With multiple grades tailored to different corrosive and thermal challenges, choosing the right variant is essential for safety, durability, and performance. From C-276’s all-around protection to C-22’s superior oxidizing resistance and B-3’s reducing acid resilience, each alloy has a role to play.
Whether you are designing a chemical reactor or an offshore structure, sasaalloy provides high-quality Hastelloy solutions that meet global standards and are ready to perform in the most demanding environments.
Post time: Jun-27-2025