Cathodic protection circuits

BEFORE discussing the present state of investigation and proposed future considerations of cathodic protection circuitry, it may be profitable to review briefly the problems posed by the observed phenomena of corrosion, in particular the corrosion of metallic surfaces in soils and solutions with which this paper will be primarily concerned. Such a review should be helpful to investigators actively engaged in corrosion studies by emphasizing the actual corrosion problems under consideration as well as present methods of approach. Such a statement of the problem helps in clarifying and unifying much of the apparently disassociated work being done in the particular field and will provide a starting point for investigating corrosion phenomena. Most of the available literature pertaining to corrosion assumes that everyone is quite familiar with the subject and therefore needs no further introduction or explanation. Such an assumption, of course, can frequently be erroneous and, for this reason, it was felt that a brief review of this subject matter would be appropriate.