Investigation of the cut-edge corrosion of organically-coated galvanized steel after accelerated atmospheric corrosion test

The cut edge corrosion of organically coated (epoxy, polyurethane and polyester) galvanized steel was investigated using electrochemical impedance spectroscopy (EIS). Measurements were performed on specimens that had been tested in an accelerated atmospheric corrosion test. The samples were subjected to 10 s fogging and 1 h awaiting cycles in an exposure cabinet (120 and 180 days) with artificial acid rain solution. According to the investigation, the coatings were damaged from the cut edge into the sheet, this distance was about 0.8 cm. These defects were more pronounced at after 180 days in proportion to after 120 days.