CORROSION PERFORMANCE OF THERMAL SPRAYED STEEL PIPES EXPOSED TO MARINE ENVIRONMENT FOR 10 YEARS
热喷涂钢柱10年海水腐蚀行为

Thermal spray committee of Japan Association of Corrosion Control (JACC) has been conducting a corrosion test of thermal sprayed Zn,Al and Zn\|Al coatings in coastal area since 1985, this paper summarizes experimental data of 10 year exposure. 12 kinds of Zn,Al and Zn\|13Al coatings were deposited on steel pipes by DC arc\|spraying and flame\|spraying in varied thickness, and 7 kinds of them were subjected to various sealing and heavy painting post\|treatment. The corrosion performance of the coated steel pipes were inspected annually by recording the apperance and coating thickness in sea air, splash and tidal zones. For 5 year exposure, no significant changes were observed for all the coatings, but Zn coatings with or without sealing suffered rust corrosion in the tidal zone after 7 year exposure. Arc\|sprayed Al with sealing, flame sprayed Zn\|Al with sealing and flame sprayed Al with heavy painting showed excellent rust resistance while flame sprayed Zn or Al without sealing allowed the corrosion of steel pipes resulting in heavy rusting.