Influence of Seawater Flow Velocity on the Morphological Characteristics of Calcareous Deposits Formed by Cathodic Protection

Abstract

The influence of seawater flow velocity on calcareous deposits formed under galvanostatic polarization mode was studied. The protection potentials of electrodes shifted positively with increasing flow velocities which were monitored versus time at various flow velocities. The whole curves of potential decay appeared two inflection points, corresponding to the different processes of crystal sedimentation. Observation by scanning electron microscope and X-ray diffraction analyses demonstrated that the ratio of magnesium in the deposits increased with flow velocities, and the main kind of crystal was brucite when the velocity was higher than 10 cm/s.