Abstract
Electrochemical corrosion measurements have been carried out with Pt-containing and Pt-free Al-diffusion coatings on IN 738 LC in a 90Na2SO4+ 10K2SO4 (mol%) melt at 1173 K. Pt improves the resistance to basic fluxing while there are no significant differences between both coating types in their resistance to acidic fluxing. The corrosion resistance of the Pt-containing coating is also higher in the passive potential region where protective scales rich in Al2O3 are formed. The reason for the different behavior of both coating types appears to be related to the high corrosion resistance of the Pt-rich surface layer of the coating and an increased Al2O3 content in the scale of the Pt-containing type.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
C. Duret, A. Davin, G. Marijnissen, and R. Pichoir, inHigh Temperature Alloys for Gas Turbines 1982, R. Brunetaudet al., eds. (D. Reidel, Dordrecht, Holland, 1982), p. 53.
M. Malik, R. Morbioli, and P. Huber, in ref. 1, p. 87.
H. W. Grünling and K. Schneider,Thin Solid Films 84, 1 (1981).
G. Lehnert, German patent TEW P. 17.96.175.0 (14.09.1968).
G. Lehnert and H. Meinhardt, Proc. Conf. Composite Materials, Konstanz, FRG 1970, Deutsche Gesellschaft für Metallkunde e. V., Oberursel (1970), p. 281.
H. Brandis, G. Lehnert, and H. Kiesheyer,Thyssen Edelst. Techn. Ber. 6, 132 (1980).
I. G. Fountain, F. A. Golightly, F. H. Stott, and G. C. Wood,Oxid. Met. 10, 341 (1976).
A. Rahmel, M. Schmidt, and M. Schorr,Oxid. Met. 18, 195 (1982).
W. T. Wu, A. Rahmel, and M. Schorr,Oxid. Met. 19, 201 (1983).
E. Erdös, H. Altorfer, and E. Denzler,Werkstoffe u. Korrosion 33, 373 (1982).
W. T. Wu, A. Rahmel, and M. Schmidt,Electrochim. Acta 28, 1487 (1983).
H.-E. Bühler and H. P. Hougardy,Atlas of Interference Layer Metallography (Deutsche Gesellschaft für Metallkunde, Oberursel, FRG, 1980). Also available from the American Society of Metals and the Metals Society.
W. T. Wu, I. Aydin, and H.-E. Bühler,Prakt. Metallogr. 19, 322 (1982).
E. Erdös, private communication.
E. Erdös, A. Rahmel, M. Schorr, M. Schmidt, and W. T. Wu,Oxid. Met. 18, 187 (1982).
R. A. Rapp and K. S. Goto, inSecond International Symposium on Molten Salts, G. Braunstein and R. Selman, eds. (The Electrochemical Society, Princeton, N.J., 1979).
D. K. Gupta and R. A. Rapp,J. Electrochem. Soc. 127, 2194 (1980).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Wu, W.T., Rahmel, A. & Schorr, M. Role of platinum in the Na2SO4-Induced hot corrosion resistance of aluminum duffusion coatings. Oxid Met 22, 59–81 (1984). https://doi.org/10.1007/BF00659249
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00659249