Calcareous deposit formed under cathodic protection in the presence of natural marine sediments: A 12 month experiment

The influence of marine sediments on calcareous deposit formed on carbon steel samples was studied in natural seawater during 12 months. The calcareous deposit formation is highly delayed compared to those formed under controlled laboratory conditions with artificial or natural seawater. Moreover, the deposit formed is essentially composed of monohydrocalcite, which is detected for the first time in calcareous deposit study. These differences seem to be related to natural conditions: the presence of sediment and organic compounds could explain the diminution of the active surface, as well as the nature of the calcareous deposit and the delay of its formation.