The Impact of Crevice Corrosion on Copper Winding in Insulating Oil with Corrosive Sulfur

Abstract

Crevice corrosion was considered to be a vital factor for corrosion. In oil immersed power equipment, the crevices were the oil gaps between copper winding or paper. In this paper, copper columns were polished by sandpaper and crevice sizes of 4μm, 25μm and 60μm were respectively prepared. After corrosion for 72 hours at 150°C in corrosive oil, the corrosion became serious with the increasing of copper-copper crevice size. Especially, the copper samples with copper-paper crevice showed the most serious corrosion. Meanwhile, the electrochemical processing of the concentration difference model was discussed, including the accelerated corrosion of anode and the reduction of DBDS-Cu in anode region.