絶縁性塗覆装の欠陥部の腐食・防食に関する考察

抄録

Protective coating with permanent high electric resistivity has been applied for the corrosion protection of underground steel pipelines, but on coated pipes pitting corrosion has been brought out in shorter period than on bare pipes. In this report the leakage resistance and corrosion rate at the pinhole of coating has been analyzed mathematically, and necessity of cathodic protection for coated pipes has been realized. The effect of cathodic protection on the defect of coating has been discussed, and the necessary characteristics for pipeline coatings has been explained.