Research on the Long-Lasting Protection Performance of Epoxy Zinc-Rich Coating Supporting System
In tropical coastal areas,high humidity and heat,high salt and high irradiation is an extremely harsh corrosive environment.Under such special conditions,the corrosion failure of metal materials has become a major bottleneck restricting the development and application of equipment,and the epoxy zinc-rich coatings commonly used in the current project in such harsh environments lack of in-depth study of the long-lasting protective performance.In this paper,through the cycle test of UV/condensation,neutral salt spray,and damp heat test,the long-term protection performance of epoxy zinc-rich coating supporting system on carbon steel in the corrosive environment of high humidity and heat,high salt and high irradiation is investigated,and the anticorrosive performance of the coating is investigated through the methods of adhesion,width of corrosion spreading at the coating scratches,surface microscopic morphology,and electrochemical impedance spectroscopy.The results show that:after 175 d cyclic accelerated corrosion test,the adhesion at different cycles of 36 d,70 d,100 d and 175 d,relative to the initial adhesion(10.45 MPa),the rate of decrease is 4.3%,10.0%,13.2%and 18.7%,respectively,although the adhesion has been reduced,but the decrease is not large.The corrosion spreading widths of the scratches at different cycles of 36 d,70 d,100 d and 175 d were 0.75 mm,1.25 mm,1.74 mm and 2.38 mm,respectively,which were all smaller than that of zinc-rich primer coatings,which was≤3 mm.SEM observations showed that the surface of the coatings produced obvious changes in four cycles of coating exposure,and a large number of block products were generated in the late stage of the test.EIS The results showed that the impedance value of the coating showed a gradual decrease from 2.93×1010 Ω·cm2 to 6.148×109 Ω·cm2 during the process of(36～100)d,while there was a small increase in the radius size of the inductive arc from 100 d to 175 d,and the impedance spectrum did not show a second time constant,which can indicate that the epoxy zinc-rich coating supporting system can still maintain integrity and homogeneity under this type of It can be indicated that the epoxy zinc-rich coating system can still keep integrity and uniformity under such environment,which is related to the cathodic protection effect of zinc powder in the coating.The results show that the epoxy zinc-rich coating system still has excellent long-term anti-corrosion performance in this kind of severe corrosive environment.
severe corrosion environmentcarbon steelepoxy zinc-richaccelerated cycle testprotection performance
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NSTL
万方数据
维普
