The Influence Of Fouling Organisms Adhesion On The Formation Of Calcareous Deposits On The Surface Of Q235 Carbon Steel

In recent years,cathodic protection technology has been developed rapidly and widely used,which provides a good solution to the corrosion of steel structures in the marine environment.Calcareous deposits will form on the surface of steel structure in the marine environment after the cathodic protection is applied.But microorganisms and marine fouling organisms in the marine environment have a certain effect on the deposition of calcareous deposits on the surface of the steel structure which is protected by cathodic protection.Therefore,to study the influence of microorganisms and marine fouling organisms' adhesion on the formation of calcareous deposits formed by cathodic protection is very important.In this experiment,we studied the effects of adhesion of sulfate reducing bacteria and marine fouling organisms on the formation calcareous deposits on Q235 carbon steel surface through scanning electron microscopy,electron spectroscopy,electrochemical impedance spectroscopy and polarization curve,fluorescence microscopy and other methods.The main contents include the following aspects:(1)the effect of polarization time on the formation calcareous deposits on Q235 carbon steel surface adhered by sulfate reducing bacteria;(2)the effect of adhesion time of sulfate reducing bacteria on the formation calcareous deposits on Q235 carbon steel surface;(3)the effect of fouling organisms adhesion on the formation of calcareous deposits formed by cathodic protection on the surface of Q235 carbon steel in the ocean environment.Through the study we found that the protection optimal performance of calcareous deposits was best when it's formed by-30 ?A/cm2 current density and polarized by 72 h.Fouling organisms adhesion and calcareous deposits formation on the surface of carbon steel can form competition,fouling organisms will make cathodic protection of intermittent discontinuous,calcareous deposits formation will be uneven and decrease in size,cathodic protection will weakened and the local corrosion rate is increased.Our research results can help us find the favorable conditions of forming calcareous deposits under the condition microorganism and large fouling organisms attached on the steel surface,and provide the theoretical foundation for the further development and practice of cathodic protection.