Corrosion Behavior of X65 and X80 Pipeline Steels under AC Interference Condition in High pH Solution

摘要

The corrosion behavior of X65 and X80 pipeline steels under AC interference in high pH solution wasinvestigated by potentiodynamic polarization curve, open circuit potential, Mott-Schottky curve andimmersion test. The results show that AC could significantly reduce the passivity of the steels, interferewith the formation of passive film, increase the instability of passive film formed on the steel, and ACwith high iAC generates a more damage to the film. The film on X65 steel has a worse stability, with alarger corrosion rate. Under AC interference, X65 steel has a worse corrosion resistance, with a moresevere localized corrosion. While X80 steel exhibits a better corrosion resistance, with a slightercorrosion status. The microstructure consisting of ferrite and pearlite is more susceptibility to ACcorrosion.