Properties of alloy 800 series (800, 800H, 800HT)

These alloys are specially designed for high-temperature applications. They offer resistance to oxidation, carbon diffusion, and corrosion, especially in high-oxygen atmospheres. They are often used in heat exchangers and petrochemical installations. Often, CEWELD® NiCro 625 and CEWELD® 21-33Mn are used as filler material. This helps maintain desired corrosion resistance and temperature resistance in the weld zone. For applications that require the highest strength and corrosion resistance, CEWELD NiCrCo 617 is recommended.

Typical chemical composition in %

Ni: 30-35
Cr: 19-23
Fe: 39.5-42.5
Al: 0.15-0.60
Ti: 0.15-0.60
C: ≤ 0.10
Cu: ≤ 0.75

Small amounts of other elements like manganese, silicon, sulfur, and phosphorus.

Corrosion resistance of Alloy 800

General Corrosion Resistance: Alloy 800 exhibits good resistance to general corrosion in various environments, including atmospheric, aqueous, and alkaline conditions.

Oxidation Resistance: It provides excellent resistance to high-temperature oxidation, making it suitable for applications in high-temperature and oxidative environments.

Carburization and Nitridation Resistance: Alloy 800 is highly resistant to carburization and nitridation at elevated temperatures, which is important for applications in carbon-rich and nitrogen-rich atmospheres.

Sulfur-Containing Environments: It shows good resistance to sulfur-containing atmospheres, making it suitable for applications in industries where sulfur compounds are present.

Chloride-Ion Stress Corrosion Cracking (SCC) Resistance: Alloy 800 offers good resistance to chloride-ion stress corrosion cracking, making it suitable for applications in chloride-rich environments.

Alloy 800 is commonly used in various applications, including furnace components, heat exchangers, petrochemical processing, chemical processing, power generation, and aerospace industry.