Growth and breakdown of passive films on metal surfaces

Technical Report · Wed May 01 04:00:00 EDT 1985

OSTI ID:5450569

Macdonald, D D; Smialowska, S; Cragnolino, G

A model based on oxide defect theory is developed for the growth of passive films on metals in aqueous environments. Growth of the film occurs as the result of inward diffusion of oxide ions, while outward diffusion of cations results in their dissolution in the environment. The electric field in the passive film is assumed to be constant, limited by dielectric breakdown in the oxide. Rate laws derived from this theory are in good agreement with experimental film growth values. The breakdown of passivity by aggressive anions, such as chloride, is also treated. Values for the critical breakdown potential and induction time for pit initiation from the model are in good agreement with literature experimental data. Measured values of film growth on some Fe-Cu-Ni alloys by ellipsometry were used with the model to evaluate the electric fields in the films.

• Research Organization: Ohio State Univ. Research Foundation, Columbus (USA)
• OSTI ID: 5450569
• Report Number(s): EPRI-NP-4069M; ON: TI85920820
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
220200* -- Nuclear Reactor Technology-- Components & Accessories
36 MATERIALS SCIENCE
360105 -- Metals & Alloys-- Corrosion & Erosion
CHALCOGENIDES
CHEMICAL REACTIONS
CHEMISTRY
CORROSION
ELECTRIC FIELDS
ELECTROCHEMISTRY
ELEMENTS
FILMS
MATERIALS
MATHEMATICAL MODELS
METALS
OXIDES
OXYGEN COMPOUNDS
REACTOR MATERIALS
SURFACE PROPERTIES