A SURVEY ON THE EFFECT OF SOIL COMPOSITION IN CORROSION BEHAVIOR OF CATHODICALLY PROTECTED BURIED PIPELINES UNDER AC INDUCED CONDITION

Abstract: Due to the expansion of high voltage Alternating Current (AC) power transmission lines and cathodically protected buried pipelines, it is becoming more and more difficult to construct them with enough safe distances between them. Thus, the pipelines are frequently exposed to induced AC interferences, which result in perturbation of Cathodic Protection (CP) due to AC corrosion. To study the above criterion, an experimental set up was used with coupons exposed to simulated soil solutions, while under both CP and AC induced condition for which an AC+DC power supply was utilized. The experiments were carried out in several simulated soil solutions corresponding to several soil samples collected from various regions along a buried pipeline with overhead parallel high voltage power transmission line. The results indicated that AC corrosion depends strongly on the composition of the soil.