Alloy 800

Incoloy® Alloy 800 (UNS N08800/W. Nr. 1.4876) is a widely used material for construction of equipment requiring corrosion resistance, heat resistance, strength, and stability for service up to 1500°F (816°C). Alloy 800 offers general corrosion resistance to many aqueous media and, by virtue of its content of nickel, resists stress corrosion cracking. At elevated temperatures it offers resistance to oxidation, carburization, and sulfidation along with rupture and creep strength. For applications requiring greater resistance to stress rupture and creep, especially at temperatures above 1500°F (816°C), Incoloy® Alloys 800H and 800HT are used. The chromium in the alloy imparts both aqueous and heat resistance. Iron provides resistance to internal oxidation. The nickel content maintains a ductile, austenitic structure. Thus, alloy 800 is readily formed, welded, and machined. I


Incoloy® alloy 800 is used in a variety of applications involving exposure to corrosive environments and high temperatures. It is used for heat-treating equipment such as baskets, trays, and fixtures. In chemical and petrochemical processing, the alloy is used for heat exchangers and other piping systems in nitric acid media especially where resistance to chloride stress-corrosion cracking is required. In nuclear power plants, it is used for steam-generator tubing. The alloy is often used in domestic appliances for sheathing of electric heating elements. In the production of paper pulp, digester-liquor heaters are often made of alloy 800. In petroleum processing, the alloy is used for heat exchangers that air cool the process stream.


Incoloy® Alloy 800 has high mechanical strength over a broad temperature range. In general, alloy 800 is used for its strength characteristics at service temperatures up to about 1500°F (816°C). At those temperatures, equipment design is usually based on tensile properties. For applications that require high creep or rupture strength, Incoloy® Alloys 800H and 800HT are used.


Incoloy® Alloy 800 (UNS N08800) is approved under the Boiler and Pressure Vessel Code of the American Society of Mechanical Engineers (ASME). Rules for construction of power boilers are defined under Section I, and those for pressure vessels under Section VIII, Divisions 1 and 2.