Effect of Marine Fouling Organisms Adhesion on Formation of Calcareous Deposits Formed by Cathodic Protection on Surface of Q235 Carbon Steel

Abstract

The effect of fouling organisms adhesion on the formation of calcareous deposits in the ocean environment was simulated by immersion test. The corrosion morphologies, the calcareous deposits composition, the corrosion kinetics of Q235 steel and fouling organisms adhesion were investigated by the methods of SEM, EDS, EIS, mass loss method and fluorescence microscope observation. The results show that the electrochemical impedance modulus value and capacitive reactance arc of the samples of forming calcareous deposits after fouling organisms adhesion are greater than the bare steel samples, but it is less than the samples of forming calcareous deposits without fouling organisms adhesion. The results show that fouling organisms adhesion can inhibit the formation of calcareous deposits and cause calcareous deposits to protect metal performance degradation. The Ca/Mg ratio of same sample gradually decreases with the increase of experimental periods, and this shows that the ability of large fouling organisms to inhibit the formation of calcareous deposits is stronger.Mass loss experiments show that large fouling organisms can inhibit local corrosion.

Keywords

• biofouling
• Q235 carbon steel
• cathodic protection
• calcareous deposit
• corrosion