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Alloy 825(Incoloy 825)

Alloy 825(Incoloy 825)


ALLOY825 is a titanium-stabilized fully austenitic

Ni-Fe-Cr alloy with additions of Cu + Mo

good resistance to stress-corrosion cracking
satisfactory resistance to pitting and crevice corrosion
good resistance to oxidizing and non-oxidizing hot acids
good mechanical properties at both room and elevated temperatures, up to approximately 550 °C (1020 °F)
approval for pressure vessels with wall temperatures up to 450 °C (842 °F)

Corrosion resistance

Alloy 825 is a versatile general engineering alloy with resistance to corrosion in acids and alkalis under both oxidizing and reducing conditions.

High nickel content gives the alloy virtual immunity to stress corrosion cracking.

Alloy 825 is good in media as diverse as sulphuric, sulphurous, phosphoric, nitric and organic acids, alkalis such as sodium or potassium hydroxide, and acidic chloride solutions.

The versatility of Alloy 825 is illustrated by its use in nuclear fuel element dissolvers where a variety of corrosive media, e. g. sulphuric and nitric acids and sodium hydroxide, are handled in the same equipment.


Alloy 825 is used in a wide variety of applications up to a temperature of approximately 550 °C (1020 °F).

Typical applications are:

components such as heating coils, tanks, crates, baskets and chains in sulphuric acid pickling plants
fuel element dissolvers
sea-water-cooled heat exchangers, offshore product piping systems; tubes and components in sour gas service
heat exchangers, evaporators, scrubbers, dip pipes etc. in phosphoric acid production
air-cooled heat exchangers in petroleum refineries
food processing
chemical plant
combustion-resistant alloy for high pressure O2 applications