A CATALYTIC MECHANISM OF ANODIC INHIBITION IN METALLIC CORROSION
It is well known that quite low concentrations of certain oxygen- containing anions, such as chromate, are effective inhibitors of aqueous corrosion of a number of metals. These results have bcen ascribed to specific adsorption of the inhibitor at anodic sites of the metal surface, or alternatively to continuous repair of the protcctivc film. Work on the corrosion of aluminum has suggested that its resistance is largely dependent on the structure of the film; thus, complete passivity is considcred to be associated with the formation of an oxide, while a hydrated oxide or hydroxide film only confers partial protection. It is postulated that the impdrtant factor in inhibition by oxygen-containing anions is their ability to cause the true oxide to be produced rather than the hydroxide which would othewise form. It is thought that the anion acts catalytically in donating its own O/sup 2-/ion to the film in competition with the hydroxyl ion from the solution. These ideas are shown to apply to other metals in addition to aluminum and explain a number of facts which are inconsistent with existing theories of anodic inhibition. (auth)
- Research Organization:
- Atomic Energy Research Establishment, Harwell, Eng.
- Sponsoring Organization:
- USDOE
- NSA Number:
- NSA-12-004172
- OSTI ID:
- 4321384
- Journal Information:
- Advances in Catalysis, Vol. Vol: 9; Other Information: Orig. Receipt Date: 31-DEC-58
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
Similar Records
Inhibition of corrosion of Al 6061, aluminum, and an aluminum-copper alloy in chloride-free aqueous media. Part 2: Behavior in basic solutions
Activating and inhibiting action of anions on hydrogen embrittlement during stress corrosion cracking of high-strength steels