The Experimental Study Of Heavy Anti-corrosion Coating In The Atmospheric Environment Of Chlor-alkali Plant

This article introduces that equipments which in the atmosphericenvironment under the chlor-alkali plants have been corroded. Compared tothe heavy anti-corrosion system in the plant, three kinds of heavyanti-corrosion system have been used. The salt spray test was used to measurethem. The electrochemical impedance spectroscopy (EIS) was used to measurethem which were soaked in NaCl solution under neutral and alkalineenvironment. According to the results of the resistant to salt spray andelectrochemical corrosion, the failure of the heavy anti-corrosion system hasbeen obtained. Finally, the primer’s mechanical properties were tested. Themain conclusions are summarized as follows:(1)According to the comparison photos that four heavy anti-corrosionsystems before and after the salt spray, they can be clearly observed. Thecorrosion protection coatings of system1have been total failure, the system2,3salt spray resistance are not satisfying. The surface of system4don’t appearany change. Therefore, the salt spray resistance of four heavy anti-corrosionsystems as follows:system4> system3> system2> system1.(2)The neutral solution immersion, the electrochemical characteristics ofcoating failure of the system1have been shown by the EIS figure. The system2,3,4’s EIS figure don’t appear failure characteristics. They can bejudged according to the spectrum curve:system4> system3> system2> system1.(3)Soaked in a solution of an alkaline environment, the system1,3’EISfigures have shown the electrochemical characteristics of the coating failure.In the EIS figures of the system2,4, although some changes appear in thespectrum curve, but they still achieve the anti-corrosion requirements. So thealkali resistance of the four heavy anti-corrosion system as follows:system4> system2> system3> system1.(4)The epoxy zinc-rich primer coating of the system2and system3(system4) are tested the mechanical properties. They have achieved a highlevel on their adhesion impact resistance, flexibility and so on.