Corrosion Behavior of High-strength Pipeline Steel and Coatings in the Simulated Sea Water Environment

Four different metal coatings of pure aluminum, aluminum zinc alloy, titanium, aluminum Titanium were prepared on the surface of X80 pipeline steel by the method of arc spraying. The microstructures and combination method between the four coatings and substrates were observed by means of metallurgical microscope. This paper use 3.5%(mass fraction) NaCl solution to simulate seawater. The corrosion potential, average corrosion rate and corrosion current density of the four metal coatings were studied through the immersion test, salt spray test and electrochemical experiment in 3.5% NaCl solution. According to the results,analyse the corrosion mechanism of different coatings compared to the different corrosion resistances. The results showed that the Al-Zn coating has the excellent comprehensive corrosion resistance.