When it comes to materials that can withstand the rigors of high-temperature environments, Alloy 800H and 800HT® stand out as two of the most reliable and durable options. These iron-nickel-chromium alloys are specifically designed for applications that require prolonged exposure to extreme heat, making them invaluable in several high-stress industries.
Composition and Differences
One of the key characteristics that set Alloy 800H and 800HT® apart is their higher carbon content compared to the standard grade Alloy 800. This enhanced carbon content improves their mechanical properties at elevated temperatures, further solidifying their reputation as go-to materials for demanding thermal applications.
Alloy 800H and 800HT® share a similar base composition, primarily consisting of iron, nickel and chromium. This combination grants them excellent resistance to oxidation, carburization and sulfidation. One of the significant differences between the two lies in the restricted aluminum and titanium content found in Alloy 800HT®, which distinguishes it from Alloy 800H. The aluminum and titanium additions present in 800HT® provide the alloy with high temperature strength and stability. This subtle yet crucial distinction impacts their performance in high-heat environments.
To meet the varying demands of such environments, Corrosion Materials stocks a dual-certified version, Alloy 800H/HT®, which provides the combined benefits and flexibility of both alloys.
Alloy 800H/HT® Products
Superior Resistance Properties of Alloy 800H/HT®
The high nickel and chromium content provides robust resistance to a variety of harsh conditions:
- Oxidation: Alloy 800H/HT® maintains its integrity and resists scaling even at elevated temperatures.
- Carburization and Sulfidation: These processes, which can degrade materials in high-temperature environments, are effectively resisted by Alloy 800H/HT®.
- Nitric Acid Resistance: This dual certified alloy can withstand nitric acid concentrations of up to 70%, making them suitable for chemical processing applications.
- Organic Acids: This dual certified alloy also exhibits good resistance to formic, acetic, and propionic acids, further broadening their applicability.
Mechanical Strength and Durability of Alloy 800H/HT®
One of the standout features of Alloy 800H/HT® is its high creep and stress rupture properties. These attributes are crucial for materials used in high-temperature environments as they ensure the material can withstand prolonged stress without deforming. Additionally, the controlled grain size of these alloys contributes to their superior performance, making them generally considered superior to the base Alloy 800.
Common Applications of Alloy 800H/HT®
Given their robust properties, Alloy 800H/HT® is used extensively in several industries, particularly those involving high-temperature processes:
- Heat Treatment and Power Generation: Typical applications include superheater and reheater tubing, headers, pigtails, outlet manifolds, and sheathing for heating elements. These components are critical in maintaining efficiency and safety in power plants and heat treatment facilities.
- Pressure Vessels and Components: Alloy 800H/HT® is approved under the ASME Boiler and Pressure Vessel Code, Section VIII, Division 1, making them suitable for manufacturing pressure vessels and other critical components that operate under high stress and temperature conditions.
EXPLORE ALLOY 800H/HT®
Alloy 800H/HT® represents the pinnacle of high-temperature alloy engineering. The alloy’s exceptional resistance to oxidation, carburization, sulfidation, and various acids, combined with their superior mechanical strength, make it ideal for a wide range of demanding applications. Whether in heat treatment, power generation, or chemical processing, Alloy 800H/HT® provides the reliability and performance required to meet the challenges of extreme environments.
Understanding the unique properties and applications of this dual certified alloy helps industries make informed decisions, ensuring safety, efficiency, and longevity in their high-temperature operations.
For more information, guidance, or to request a quote, feel free to reach out to our experts at Corrosion Materials. Our team is here to assist you with all your high-temperature alloy needs.
*800HT® is a registered trademark of the Special Metals Corporation group of companies.