Chromia scale growth in alloy oxidation and the reactive element effect
- CNRS, Toulouse (France). Lab. Materiaux
- Ohio State Univ., Columbus, OH (United States). Dept. of Materials Science and Engineering
An analysis for the kinetics of scale growth involving simultaneous cation and anion diffusion, and for anion diffusion with blocked cation diffusion, is presented and compared to experimental data in the literature. The significant reduction in scaling kinetics for the growth of chromia on pure Cr and on Fe-, Ni-, or Co-base alloys is attributed to the elimination of cation diffusion by the blocking of the cationic reaction step at the metal/scale interface. Large highly charge reactive element (RE) ions segregate at the metal/scale interface and pin the misfit dislocations whose climb otherwise serves to create interstitial cations (or annihilate vacancies). Then scale growth must proceed by oxygen diffusion over anion vacancies, corresponding to the lateral climb of misorientation dislocation (reaction at monoatomic steps) at the metal/scale interface. This poisoned interface model provides an interpretation for the reactive element effect (REE) which is consistent with the four well-known REE characteristics.
- OSTI ID:
- 6006132
- Journal Information:
- Journal of the Electrochemical Society; (United States), Journal Name: Journal of the Electrochemical Society; (United States) Vol. 140:10; ISSN 0013-4651; ISSN JESOAN
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360105* -- Metals & Alloys-- Corrosion & Erosion
ALLOYS
CERIUM
CHALCOGENIDES
CHEMICAL REACTIONS
CHROMIUM
CHROMIUM ALLOYS
CHROMIUM COMPOUNDS
CHROMIUM OXIDES
COATINGS
COBALT ALLOYS
COBALT BASE ALLOYS
CRYSTAL DEFECTS
CRYSTAL GROWTH
CRYSTAL STRUCTURE
DIFFUSION
DISLOCATIONS
DOPED MATERIALS
ELEMENTS
INTERFACES
IRON ALLOYS
IRON BASE ALLOYS
KINETICS
LINE DEFECTS
MATERIALS
MATHEMATICAL MODELS
METALS
NICKEL ALLOYS
NICKEL BASE ALLOYS
OXIDATION
OXIDES
OXYGEN COMPOUNDS
PROTECTIVE COATINGS
RARE EARTHS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
YTTRIUM