无溶剂环氧防腐涂层在模拟海水冲刷条件下的电化学行为

he electrochemical behavior of three solvent- free epoxy coatings on Q345E carbon steel during corrosion-erosion induced by flowing slurry of simulated sea water with 1% (mass fraction) of sand at 60 was investigated by means of electrochemical impedance spectroscopy (EIS), scanning electron microscope (SEM) and confocal laser scanning microscopy (CLSM), respectively. The results showed that the flowing slurry induced erosion aggravated the deterioration of coatings. The amine-cured epoxy powder coating and phenolic aldehyde amine-cured liquid epoxy coating were cured with slow speed and thus much densified, accordingly, their deterioration processexperienced three stages: firstly, the inward migration of corrosive medium; secondly, the corrosion initiation of the substrate metal; thirdly, the corrosion propagation of the substrate metal beneath the coating and finally the failure of coatings. On the contrary, the phenolic aldehyde-cured epoxy powder coating was cured with fast speed and thus much porous, its deterioration process experienced two stages with a shortened second stage. Thereforethe existence of pores in the coating is one of the important factors for inducing failure of coatings during corrosion-erosion.