سال انتشار: ۱۳۸۴
محل انتشار: نهمین کنگره ملی خوردگی ایران
تعداد صفحات: ۲۱
Victor Ashworth – Full Professor Ashworth Corrosion Management Ltd (UK).
Voltages can be induced on pipelines placed in close proximity to overhead power lines. The voltages derive from capacitive, inductive and conductive coupling effects. The risk of electric shock that coupling produces is the primary concern. However, there are other secondary concerns that are of interest to the corrosion engineer. These include potential damage to the pipeline coating because of the substantial voltage gradients that may develop. Further any induced AC leaking from the line may cause corrosion damage and also adversely affect the efficacy of a cathodic protection system. The evidence is that in normal, moist soils, the level of AC induced corrosion damage will be modest. However, in waterlogged soils severe damage may occur because of the high AC current densities that can exist at coating holidays and the enhanced efficiency of the AC induced dissolution process under these conditions. AC also introduces the potential for damage to the CP power sources.