Abstract
While the importance of calcareous deposits to the effectiveness and efficiency of marine cathodic protection is generally recognized, there has been relatively little research directed toward rationalizing the structure and properties of deposits and the role of influential variables in deposit formation. This paper reviews those properties of seawater which are pertinent to the occurrence of calcareous deposits and emphasizes how physical and chemical variations of seawater might be expected to alter the nature of these surface films. Previous research regarding deposits is critically reviewed, and it is projected that the chemistry and structure of these surface films should depend on their nucleation and growth kinetics. These, in turn, should be determined by variables such as potential, current, time, pressure, temperature, seawater chemistry, velocity, and substrate surface condition. In conclusion, a more comprehensive study of calcareous deposits would be timely and appropriate in that a better understanding of the interrelationship between formation conditions, deposit structure, and properties and the effectiveness of cathodic protection might be realized.
