Nickel-based alloys play an essential role in modern industries that require exceptional resistance to heat, corrosion, and mechanical stress. Among the most recognized families of these alloys are Incoloy and Hastelloy. Both have been widely adopted in chemical processing, marine engineering, power generation, aerospace, and environmental industries.
Although these alloys share some similarities, they also possess distinct differences in composition, performance, and application suitability. Understanding these differences is crucial for engineers, buyers, and procurement specialists who need to select the most cost-effective and technically appropriate material for their projects.
This article provides a comprehensive comparison of Incoloy and Hastelloy, highlighting their compositions, properties, advantages, limitations, and typical applications.
What is Incoloy?
Incoloy is a trademarked name owned by Special Metals Corporation. It refers to a family of nickel-iron-chromium alloys that are designed primarily for high strength and oxidation resistance in elevated-temperature service.
Key Features of Incoloy
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Base Composition: Nickel with significant amounts of iron and chromium.
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High Temperature Strength: Performs well in environments above 1000°F (538°C).
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Resistance to Oxidation: Excellent resistance to oxidation and carburization in high-temperature atmospheres.
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Weldability: Good fabrication and welding characteristics.
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Common Grades: Incoloy 800, 800H, 800HT, 825.
Applications of Incoloy
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Heat exchangers
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Industrial furnaces
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Power generation boilers
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Petrochemical plants
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Nuclear power systems
What is Hastelloy?
Hastelloy is also a trademark, owned by Haynes International. It refers to a family of corrosion-resistant metal alloys mainly composed of nickel, with varying amounts of molybdenum, chromium, and iron.
Key Features of Hastelloy
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Base Composition: Nickel with high molybdenum and chromium.
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Superior Corrosion Resistance: Outstanding resistance to a wide range of aggressive chemicals, including strong oxidizers and reducing agents.
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Resistance to Localized Attack: Excellent resistance to pitting, crevice corrosion, and stress corrosion cracking.
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Versatility: Performs well in both oxidizing and reducing environments.
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Common Grades: Hastelloy C22, C276, B2, B3.
Applications of Hastelloy
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Chemical processing plants
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Pollution control equipment
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Pulp and paper industry
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Flue gas scrubbers
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Marine applications
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Pharmaceutical and food processing equipment
Composition Comparison
Incoloy
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Nickel: 30–45%
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Iron: 30–50%
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Chromium: 19–23%
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Small amounts of titanium, aluminum, or copper depending on grade
Hastelloy
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Nickel: 50–70%
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Molybdenum: 15–30%
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Chromium: 14–22%
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Small amounts of iron, cobalt, tungsten depending on grade
Key Difference: Incoloy has a higher iron content and is designed for high-temperature oxidation resistance, while Hastelloy contains much more molybdenum, making it exceptionally resistant to corrosion in harsh chemical environments.
Property Comparison
| Property | Incoloy | Hastelloy |
|---|---|---|
| Primary Focus | High temperature strength and oxidation resistance | Superior corrosion resistance in aggressive chemicals |
| Corrosion Resistance | Moderate (good in oxidizing environments) | Excellent (handles both oxidizing and reducing environments) |
| Strength at High Temperatures | Very strong above 1000°F | Moderate, not as strong as Incoloy at extreme temperatures |
| Weldability and Fabrication | Good | Good, but some grades require special techniques |
| Cost | Generally lower than Hastelloy | Higher due to nickel and molybdenum content |
Advantages of Incoloy
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Cost-effective compared to Hastelloy.
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Excellent performance at elevated temperatures.
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Good resistance to oxidation and carburization.
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Widely available in multiple product forms.
Advantages of Hastelloy
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Outstanding corrosion resistance in chemical plants.
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Excellent resistance to stress corrosion cracking.
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Performs well in both oxidizing and reducing conditions.
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Handles aggressive media like hydrochloric acid, sulfuric acid, and seawater.
Limitations
Incoloy
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Less resistant to strong acids compared to Hastelloy.
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May not be suitable for highly reducing environments.
Hastelloy
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Higher cost due to nickel and molybdenum content.
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Lower strength at very high temperatures compared to Incoloy.
When to Use Incoloy vs Hastelloy
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Use Incoloy if:
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The application involves high temperatures and oxidizing atmospheres.
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Cost is a critical factor and chemical exposure is moderate.
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Long-term structural stability at elevated temperature is required.
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Use Hastelloy if:
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The environment involves aggressive chemicals and acids.
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Protection against localized corrosion (pitting, crevice) is essential.
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Equipment must handle fluctuating chemical environments.
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Industrial Case Examples
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Power Generation Plant: Incoloy 800H is used in superheater tubes for its ability to withstand oxidation and thermal stress.
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Chemical Processing Plant: Hastelloy C276 is chosen for reactor vessels exposed to hydrochloric acid and sulfuric acid mixtures.
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Desalination Plant: Hastelloy alloys resist pitting from seawater, while Incoloy may suffice in less aggressive brine systems.
Future Trends in Nickel Alloys
With industries demanding higher efficiency and durability, both Incoloy and Hastelloy will continue to play a major role. Advanced formulations are being developed to improve mechanical performance and extend service life while reducing costs.
Environmental regulations and sustainability goals will also encourage more widespread use of these alloys in renewable energy projects, carbon capture systems, and waste treatment facilities.
Why Source from sasaalloy
When choosing nickel alloys for industrial applications, supplier reliability is just as important as material performance. sasaalloy provides both Incoloy and Hastelloy products in bars, sheets, tubes, and customized components that comply with ASTM, ASME, and EN standards. With strict quality inspection, international certifications, and global logistics support, sasaalloy ensures clients receive high-quality products with consistent performance.
Conclusion
While Incoloy and Hastelloy are both nickel-based alloys, their differences are significant. Incoloy is optimized for high-temperature applications with moderate corrosion resistance, making it ideal for power plants, furnaces, and heat exchangers. Hastelloy, on the other hand, excels in aggressive chemical environments, offering unmatched corrosion resistance in industries such as chemical processing and marine engineering.
By understanding the distinctions between these two alloy families, engineers and procurement managers can make informed decisions that maximize both performance and cost efficiency in their projects.
Post time: Sep-05-2025