Retrofit Cathodic Protection Design for Depolarized and Partially Depolarized Structure

Abstract Experiments were performed whereby steel specimens in natural seawater were successively cathodically polarized, depolarized or partially depolarized, and then repolarized to simulate the life cycle and retrofit of a galvanic cathodic protection (CP) system on space-frame-type offshore structures. Emphasis was placed upon the current density required for repolarization because of the importance of this parameter in the design of CP retrofit systems. Relationships were established between the steady-state current density during the initial and partial depolarization periods and the current density demand for repolarization.