What is the Difference Between Hastelloy and INCOLOY?

In the field of specialty metals, Hastelloy and INCOLOY are two well-known families of alloys that are widely used in demanding industrial environments. Both are engineered to resist corrosion, oxidation, and high-temperature stress. However, they are not the same. Each family has distinct compositions, properties, and ideal applications.

Understanding the difference between Hastelloy and INCOLOY is essential for engineers, procurement managers, and project designers tasked with selecting the right material for chemical plants, power stations, marine systems, and aerospace applications.

This article provides an in-depth comparison of Hastelloy and INCOLOY, covering their composition, mechanical properties, advantages, and industrial uses.

1. Introduction to Nickel-Based Alloys

Nickel-based alloys have become indispensable in modern industries because of their ability to withstand extreme environments. They generally combine nickel with elements like chromium, molybdenum, and iron to deliver excellent corrosion resistance and high-temperature stability.

Both Hastelloy and INCOLOY belong to this category but serve different performance needs.

2. What is Hastelloy?

Hastelloy is a trademarked family of corrosion-resistant metal alloys primarily composed of nickel, molybdenum, and chromium. Developed by Haynes International, Hastelloy is particularly known for resisting aggressive chemical environments.

Composition

  • Nickel (over 50%)

  • Molybdenum (15–30%)

  • Chromium (15–20%)

  • Small additions of iron, cobalt, or tungsten depending on the grade.

Properties

  • Exceptional resistance to strong oxidizers and reducers.

  • High resistance to localized corrosion such as pitting and crevice corrosion.

  • Outstanding performance in acidic environments like hydrochloric acid and sulfuric acid.

  • Maintains mechanical strength at moderate to high temperatures.

Common Grades

  • Hastelloy C-22: Known for excellent resistance to oxidizing agents.

  • Hastelloy C-276: Highly versatile, used in harsh chemical processing.

  • Hastelloy B-2: Optimized for hydrochloric acid environments.

3. What is INCOLOY?

INCOLOY is a trademarked family of nickel-iron-chromium alloys produced by Special Metals Corporation. It is designed to perform in environments requiring corrosion resistance at high temperatures, while also being more cost-efficient compared to high-nickel alloys.

Composition

  • Nickel (30–45%)

  • Iron (balance)

  • Chromium (19–25%)

  • Optional additions of titanium, copper, and molybdenum.

Properties

  • Good strength at elevated temperatures.

  • High resistance to oxidation and carburization.

  • Excellent corrosion resistance in acidic and aqueous environments.

  • More economical than Hastelloy due to higher iron content.

Common Grades

  • INCOLOY 800: Heat and oxidation resistance, used in furnace equipment.

  • INCOLOY 825: Excellent resistance to acids, widely used in chemical plants.

  • INCOLOY 901: High creep strength, suitable for turbine components.

4. Key Differences Between Hastelloy and INCOLOY

Feature Hastelloy INCOLOY
Nickel Content Very high (50% or more) Moderate (30–45%)
Iron Content Low High
Molybdenum High (up to 30%) for superior corrosion resistance Lower, only in certain grades
High-Temperature Strength Strong but primarily focused on corrosion resistance Superior for high-temperature creep and oxidation
Corrosion Resistance Exceptional, especially in chemical and acidic environments Very good, but not as strong as Hastelloy in highly reducing acids
Cost More expensive due to higher nickel and molybdenum content More cost-effective due to higher iron content
Best Applications Chemical processing, marine, pharmaceutical Power generation, oil and gas, heat exchangers

5. Performance in Corrosive Environments

Hastelloy

Hastelloy outperforms INCOLOY in highly aggressive chemical settings, such as environments containing hydrochloric acid, sulfuric acid, or chlorine gas. Its high molybdenum content makes it particularly resistant to pitting and crevice corrosion.

INCOLOY

INCOLOY alloys are still corrosion resistant but are better suited for moderately aggressive environments, especially where high temperatures are involved. They balance performance with cost efficiency.

6. Performance at High Temperatures

  • Hastelloy: Performs well at moderate to high temperatures but is not specifically designed for extreme creep resistance.

  • INCOLOY: Excels at high-temperature performance, retaining mechanical strength in furnaces, turbines, and reactors.

7. Industrial Applications

Hastelloy

  • Chemical reactors and process vessels.

  • Piping and fittings in chemical industries.

  • Marine equipment exposed to saltwater.

  • Pollution control and flue gas scrubbers.

  • Pharmaceutical processing equipment.

INCOLOY

  • Heat exchangers and condenser tubes.

  • Furnace equipment and radiant tubes.

  • Oil and gas piping systems.

  • Steam generators in nuclear plants.

  • Aerospace turbine components.

8. Advantages of Hastelloy

  • Superior corrosion resistance in aggressive chemicals.

  • Excellent resistance to localized corrosion mechanisms.

  • Reliable performance in marine and acidic environments.

9. Advantages of INCOLOY

  • Strong performance at elevated temperatures.

  • Good resistance to oxidation and carburization.

  • Cost-effective alternative to high-nickel alloys.

  • Easier to fabricate and weld compared to some Hastelloy grades.

10. Limitations of Each

Hastelloy

  • Higher cost due to its composition.

  • Limited creep resistance at extreme high temperatures compared to INCOLOY.

INCOLOY

  • Less corrosion resistance than Hastelloy in reducing acids.

  • Performance can be limited in environments with highly aggressive chemicals.

11. Sustainability and Recycling

Both Hastelloy and INCOLOY are recyclable materials, and their nickel and chromium content ensures strong demand for recycling. Recycling reduces environmental impact and contributes to sustainability initiatives in heavy industries.

12. How to Choose Between Hastelloy and INCOLOY

When deciding between Hastelloy and INCOLOY, consider the following:

  • Choose Hastelloy when your project involves aggressive acids, chlorides, or marine environments.

  • Choose INCOLOY when you need strength and stability at high temperatures combined with good corrosion resistance and lower cost.

Working with reliable suppliers like sasaalloy ensures that you get certified materials tailored to your industry requirements.

13. Future Outlook for Hastelloy and INCOLOY

The global demand for specialty alloys is expected to rise with advancements in:

  • Renewable energy technologies (geothermal and wind).

  • Electric vehicles requiring lightweight, durable materials.

  • Expansion of chemical processing plants.

  • Aerospace and defense projects demanding extreme material performance.

Conclusion

While both Hastelloy and INCOLOY are nickel-based alloys, they are designed for different performance needs. Hastelloy excels in aggressive chemical and marine environments thanks to its high molybdenum content, while INCOLOY is optimized for high-temperature strength and cost-effective durability.

The choice depends on whether your project prioritizes corrosion resistance or high-temperature mechanical performance. For industries seeking expert guidance and reliable supply of high-performance alloys, sasaalloy provides both Hastelloy and INCOLOY solutions that meet international standards and support critical applications worldwide.

Post time: Aug-27-2025