Effects of non-stationary stray current on carbon steel buried pipelines under cathodic protection

DC stray currents may cause severe corrosion on buried carbon steel pipelines even if in cathodic protection. According to international standard anodic interference is unacceptable if the IR-free potential is more positive than the protection potential (−0.85 V CSE). But, duration and magnitude of the anodic peak is not defined. The criterion appears to be too restrictive if short periods of anodic interference are established. This paper deals with the study of the effects of anodic interference on carbon steel in cathodic protection in soil-simulating environment in the presence of DC interference at varying peak current density and duration.