Super Alloy Incoloy Alloy 800 (UNS N08800) Pipe & Tube

--800 vs 800HT: Understanding the Differences

Incoloy 800 family includes 800, 800H, and 800HT grades. Learn which grade suits your high-temperature application—whether for ethylene cracking furnaces, steam superheaters, or heat treatment muffles. Key selection criteria explained.

Ethylene cracking furnace tubes, steam superheaters, and heat treatment muffle furnaces—these high-temperature reducing atmosphere environments are precisely where Incoloy 800 excels. Understanding its advantages is crucial for making the right material selection decisions.

800 vs 800HT

The Incoloy 800 series includes three grades: 800, 800H, and 800HT. 800H (carbon content ≥0.05%) and 800HT (carbon content 0.06-0.10%) are specifically designed for high-temperature creep strength and are suitable for long-term high-temperature, high-pressure applications; the standard 800 is suitable for slightly lower-temperature or lower-pressure applications. It is essential to distinguish the technical requirements differences among these three grades when selecting materials.

Material Countermeasures for Carburizing Environments

Ethylene cracking furnace tubes operate in a high-temperature reducing atmosphere, where carburizing is the primary failure mode. Incoloy 800's high chromium content (19-23%) forms a dense oxide film on the surface, effectively preventing carbon atom penetration. Compared to ordinary austenitic stainless steel, its resistance to carburization is significantly improved, making it a classic choice for petrochemical high-temperature cracking units.

Procurement and Technical Validation

High-temperature applications place extremely stringent requirements on materials. During procurement, it is necessary to confirm: whether the carbon content meets the standards (800H/800HT have a clearly defined lower limit); whether the heat treatment is solution annealing; and whether high-temperature tensile and creep data are available. For long-term service projects, an intergranular corrosion susceptibility assessment is recommended.

MTSCO's High-Temperature Alloy Supply

We can supply the full range of Incoloy 800/800H/800HT seamless pipes and matching fittings. Relying on a complete supply chain and quality inspection process, we ensure a stable delivery of high-temperature alloy materials to meet the stringent requirements of customers in the petrochemical and energy industries.