Long Term Diffusion Studies in Fe Aluminide Coatings Deposited by Slurry Application on Ferritic Steel

Alina Agüero; Vanessa González; Marcos Gutiérrez

doi:10.4028/www.scientific.net/DDF.289-292.243

Paper Titles

Grain Boundary Diffusion of Fe in High-Purity Copper
p.211

Investigation of Phase Transformation of Forged Steel Cold Rolls due to Heat Affecting and Prevent its Failure
p.219

Diffusion Enhanced Rumpling Associated with Martensitic Transformation upon Cycling of Aluminide Bond-Coats
p.227

Diffusion of a Corroding Electrolyte through Defective Electroplated Ceria Based Coatings
p.235

Long Term Diffusion Studies in Fe Aluminide Coatings Deposited by Slurry Application on Ferritic Steel
p.243

Scanning Kelvin Probe Study on the Stability of the Steel/Coating Interfaces Contaminated by Soluble Salts
p.253

Diffusion Aluminide Coatings Using Spherical Micro-Sized Aluminium Particles
p.261

Numerical Determination of Intrinsic Diffusion Coefficient of Aluminide Coatings on Metals
p.269

Implications of Diffusion on the Composition and Microstructures of Platinum Modified Aluminide Coatings on CMSX-4 Single Crystal Superalloy
p.277

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Long Term Diffusion Studies in Fe Aluminide Coatings Deposited by Slurry Application on Ferritic Steel

Abstract:

Diffusion iron aluminide coatings have shown excellent resistance to high temperature oxidation in air, corrosive atmospheres and steam. A study of the diffusion behaviour of slurry applied diffusion aluminide coatings deposited on ferritic steel have been carried out under a 100% flowing steam atmosphere for up to 50,000 h at 650 °C. The results have shown that initially, the coating forms by outward growth possibly including the dissolution of the steel in molten aluminium. At later stages, during exposure to steam at 650 °C, aluminium diffuses inward and moreover, Fe also diffuses outward resulting in the progressive development of Kirkendall porosity. Results have also indicated that in order to form a pure protective Al2O3 scale the Al wt.% has to be > 4. Below this content Al-Fe mixed oxides develop exhibiting a less protective behaviour.