AN INVESTIGATION INTO THE INFLUENCE OF SURF ACE FILMS ON THE MECHANISM OF CATHODIC PROTECTION

摘要

To understand Cathodic Protection (CP) better,electrochemical studies and surface chemistry were used to establish what is actually happening when metal specimens are cathodically protected at a series of potentials in aerated 3.5% NaCl Solution.It was found that films are formed and that these significantly affect the current demand and corrosion rate of the test specimens.The specimen with the least corrosion rate and most coherent film was at-1300 mV (vs Ag/AgCl/3.5% NaCI),but this is a potential where there can be significant hydroxide formation (OH) which can have detrimental side effects.