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Crevice corrosion: calculation of the voltage and current distribution along the crevice
Author(s) -
Vicentini B.,
Taccani G.,
Sinigaglia D.
Publication year - 1971
Publication title -
materials and corrosion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.487
H-Index - 55
eISSN - 1521-4176
pISSN - 0947-5117
DOI - 10.1002/maco.19710221103
Subject(s) - shielded cable , anode , crevice corrosion , voltage , materials science , metal , electrolyte , corrosion , metallurgy , current (fluid) , composite material , electrical engineering , mechanics , electrode , chemistry , physics , engineering
This paper refers to a method for cal‐culating and determining the distribution along a crevice of given geometrical characteristics of voltage and c. d. ex‐changed between the electrolytic solution and the shielded surface of a metallic material susceptible of active‐passive transition. This method has been applied to a par‐tially shielded sample of CF‐8 stainless steel in deaerated 0, sM H 2 SO 4 at 25°C; the experimental results referring to this case are known from the literature (2). The slight differences found between the analytical and experimental results have been attributed especially to the simplifying hypothesis of neglecting in the calculation the modifications resistivity of the solution in the course of the cre‐vice corrosion of the metallic material. Nevertheless, this method is easily and usefully applicable to the anodic protec‐tion of industrial apparatus in which narrow crevices are present, by using the knowledge of the experimental anodic behaviour of metallic materials in the aggressive media. Finally, for a given metallic material, and for given aggressive medium and voltage value applied to the free surface, but for different values of the depth L the crevice, it has been demonstrated that there exist either one stable voltage distribution along the crevice independent of the initial surface state of the metal‐lic material, or two stable voltage distri‐butions, each one depending on the initial active or passive surface state.