Incoloy 800H Alloy is an austenitic high-strength solid-solution Ni-Fe-Cr Alloy with controlled levels of C, Al, Ti, Si and Mg and increased content of (Al + Ti).
A special solution anneal treatment gives highest creep-rupture strength above
700 ℃ due to the precipitation of TiC.
Below 700℃, gamma prime precipitates combined with loss of ductility.
excellent creep strength at temperature above 700 ℃
- good resistance to reducing, oxidizing and nitriding atmospheres and to atmospheres which alternate between reducing and oxidizing conditions
- metallurgical stability in long-term application at high temperatures
For applications where frequent excursions to temperatures lower than 700 ℃ during service cannot be excluded or parts of the material are permanently exposed to a temperature below 700 ℃, the use of Incoloy 800H is recommended.
The high nickel and chromium contents of Incoloy 800H/HT Alloy ensure excellent resistance to oxidation.
The alloys are also very resistant to carburization, nitridation and oxidizing sulphur-bearing atmospheres.
The protective oxide film which is formed is adherent in both static and cyclic conditions of heating and cooling, and resistance to carburization is enhanced when a thin film of oxide is formed on the alloy through pre-oxidation prior to service. Resistance to hydrogen is excellent and Alloy800H/HT are standard materials used in the production of hydrogen in steam/hydrocarbon reforming processes.
Applications of Incoloy 800H:
Due to high strength during long periods of service and resistance to carburization and nitridation, Incoloy 800H/HT Alloy have found many applications in steam/hydrocarbon reforming for components such as: pigtails, headers/collectors/manifolds, transfer piping, catalyst tubes (in lowpressure processes) and quench-system piping.
Typical applications are:
- ethylene pyrolysis tubing in convection and radiant sections – resistance to carburization and good mechanical properties
- ethylene dichloride cracking tubes resistance to carburization and to dry hydrogen chloride and chlorine
- cracking tubes used in the production of acetic anhydride and ketene – high strength, resistance to both carburization and the formation of sigma phase
- components, e.g. heat exchangers, piping systems etc., in coal conversion plants
- steam generator tubing in helium cooled, high temperature reactor systems ? high strength, resistance to helium and to steam
|Condition||Yield Strength(Mpa)||Tensile Strength(Mpa)||Elongation(%)||Hardness(HB)|
|ASTM Min Value||Solution Annealed||170||450||30|
|Typical Values at RT||Solution Annealed||245||559||40||140|
International Specification Comparison chart
Product: Sheet, Coil, Pipe, Bar, Wire and Forgings