Passivity breakdown and pitting corrosion of binary alloys

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Abstract

PITTING corrosion—the localized dissolution of a passivated (oxide-covered) metal in the presence of a solution of certain anionic species—is a major cause of failure of metal structures. The breakdown of extremely thin (1 nm thick), highly stable passivating layers typically occurs in a sporadic, localized and stochastic fashion1,2, rather than as a catastrophic, global process. Using a model of a random binary iron–chromium alloy, we have shown previously3–6 that experimental observations of passivity of stainless steels can be explained by assuming that it is controlled by the selective dissolution of iron7. Thus if the chromium content is above a certain threshold (the percolation limit8), clusters of iron are finite and dissolution will proceed for a while and then stop. Oxidation of surface chromium atoms to form Cr—O—Cr linkages then creates a passive state in which the entire surface is covered with such a layer3,5. Here we show that, by adding to this model the further assumption that there is a small but finite dissolution rate for surface chromium atoms, one obtains a mechanism for the triggering of pitting corrosion of stainless steels that is consistent with experimental studies.

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References

  1. 1

    Williams, D. E., Westcott, C. & Fleischmann, M. J. electrochem. Soc. 132, 1796–1804 (1985); J. electmchem. Soc. 132, 1804–1811 (1985).

  2. 2

    Shibata, T. & Takeyama, T. Nature 260, 315–316 (1976).

  3. 3

    Sieradzki, K. & Newman, R. C. J. electrochem. Soc. 133, 1979–1980 (1986).

  4. 4

    Newman, R. C., Foong, T. M. & Sieradzki, K. Corros. Sci. 28, 523–527 (1988).

  5. 5

    Song, Q., Newman, R. C., Cottis, R. A. & Sieradzki, K. J. electrochem. Soc. 137, 435–439 (1990).

  6. 6

    Song, Q., Newman, R. C., Cottis, R. A. & Sieradzki, K. Corros. Sci. 31, 621–626 (1990).

  7. 7

    Burstein, G. T. & Marshall, P. I. Corros. Sci. 24, 449–462 (1984).

  8. 8

    Stauffer, D. Introduction to Percolation Theory (Taylor & Francis, London, 1985).

  9. 9

    Heusler, K. E. Corros. Sci. 31, 597 (1990).

  10. 10

    Wiilliams, D. E., Westcott, C. & Fleischmann, M. in Passivity of Metals and Semiconductors: Proc. 5th Int. Symp. on Passivity Bombannes, France, 1983 (ed. Froment, M.) 217 (Elsevier, Amsterdam, 1983).

  11. 11

    Balkwill, P., Stewart, J., Wells, D. B., Westcott, C. & Williams, D. E. in Corrosion Science and Engineering: Marcel Pourbaix 85th Birthday Symp. (eds Rapp, R. A., Gokcen, N. A. & Pourbaix, A.) 295–306 (CEBELCOR, Brussels, 1989).

  12. 12

    Stewart, J. thesis, University of Southampton (1990).

  13. 13

    Szlarska-Smialowska, Z. Pitting Corrosion of Metals (National Association of Corrosion Engineers, Houston, 1986).

  14. 14

    Hakkarainen, T. in Corrosion Chemistry within Pits, Crevices and Cracks (ed. Turnbull, A.) 17–26 (HMSO, London, 1987).

  15. 15

    Gaudet, G. T. et al. Am. Inst. Chem. Eng. J. 32, 949–958 (1986).

  16. 17

    Westcott, C. in Electrochemistry Vol. 10: Spec. Per. Rep. (ed. Pletcher, D.) 85–116 (Royal Society of Chemistry, London, 1985).

  17. 18

    Urquidi-Macdonald, M. & Macdonald, D. D. J. electrochem. Soc. 136, 961–967 (1989).

  18. 19

    Heusler, K. E. & Fischer, L. Werkst. U Korros. 27, 551 (1976).

  19. 20

    Hashimoto, K. in Passivity of Metals and Semiconductors: Proc. 5th Int. Symp. on Passivity Bombannes, France, 1983 (ed. Froment, M.) 247–252 (Elsevier, Amsterdam, 1983).

  20. 21

    Okada, T. Corros. Sci. 31, 453–458 (1990).

  21. 22

    Okada, T. Electrochim. Acta 33, 389 (1988).

  22. 23

    Okada, T. J. electrochem. Soc. 131, 241 (1984).

  23. 24

    Sato, N. J. electrochem. Soc. 129, 260–264 (1982).

  24. 25

    Sieradzki, K., Corderman, R. R., Shukla, K. & Newman, R. C. Phil. Mag. A 59, 713–746 (1989).

  25. 26

    Brüesch, P., Müller, K., Atrens, A. & Neff, H. Appl. Phys. A 38, 1 (1985).

  26. 27

    Kruger, J., Long, G. G., Zhang, Z. & Tanaka, D. K. Corros. Sci. 31, 111–120 (1990).

  27. 28

    Okamoto, G. Corros. Sci. 13, 471–489 (1973).

  28. 29

    Asami, K., Hashimoto, K. & Shimodaira, S. Corros. Sci. 18, 151–160 (1978).

  29. 30

    Mitchell, D. F., Sproule, G. I. & Graham, M. J. Appl. Surf. Sci. 21, 199–209 (1985).

  30. 31

    Riley, A. M., Wells, D. B. & Williams, D. E. Corros. Sci. (in the press).

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Williams, D., Newman, R., Song, Q. et al. Passivity breakdown and pitting corrosion of binary alloys. Nature 350, 216–219 (1991) doi:10.1038/350216a0

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