Causes and Treatment Scheme of Tower Foot Corrosion of a 500kV Transmission Tower

The causes of severe corrosion of a 500kV transmission tower foot were analyzed and a fix scheme wasformulated.The results of macro inspection,SEM,EDS and XRD analyses of corrosion products sampled from abovepedestal show that the corrosion of tower foot occurring on the pedestal and protective plate surface was localizedcorrosion.The mainly reason was SO2in atmosphere.The position of tower foot had the highest concentration ofSO2.Because of the existence of SO2,the corrosion rate was much higher than that of in the pure air.The structureof corrosion products was porous and service environment was in moist condition,which met the conditions ofelectrochemical corrosion continuous development.These factors worked together and led to a very high corrosion rateof tower foot,the corrosion thinning reached 50% within 1~2a.Thus a welding repair and anticorrosive coatingsystem of corresponding solution was formulated.