Understanding the conditions in a coating disbonded region on buried pipelines is technically challenging but practically significant. It is believed that shielding of cathodic protection (CP) current by a disbonded coating can be a large source of pipeline external corrosion. A mathematical model is developed that enables predicting the chemistry, corrosion potential and rate of pipe steel in a coating disbonded region. This model allows for examining the effect of CP penetration through either or both the holiday and the disbonded coating on the underneath chemistry and corrosion rate. A coating disbonded region with a variable gap is used in the modeling. In this paper, the fundamental principles of the model, some key model results and the practical implications of the results are reported and discussed.
Predicting the chemistry and corrosion rates in a coating disbonded region with or without cathodic current penetrating in via the holiday and coating
2011
30 Seiten, 10 Bilder, 3 Tabellen, 41 Quellen
Aufsatz (Konferenz)
Englisch
Cathodic protection potential penetration under disbonded pipeline coating
Tema Archiv | 1994
|Distribution of steady-state cathodic currents underneath a disbonded coating
Tema Archiv | 1994
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