Influence of Oceanic Biofouling on Corrosion of Carbon Steel in Seawater

With the field exposure method,the appearance and characteristics of carbon steel exposed to the seawater in Qingdao and Xiamen for 0.25-4 years were observed,and their relationship was discussed.The SRB numbers in the internal rust layer of marine foulings and deposit rust layer were obtained with the Most Probable Number(MPN) method and then the relationship between biofouling and localized corrosion of carbon steel was disscussed.The results revealed that SRB existed in internal layer under both the marine foulings and deposit rust layer.The macrofouling and surface of rust layer corresponded well with the corrosion morphology of carbon steel.Corrosion on the surface covered with marine foulings with large hard shells was slighter than that covered with loose salmon pink rust layer because of lower activity of SRB and oxygen content.