Corrosion Behaviour Of Mild Steel In Seabed Sediment

It has been attentioned that the corrosion and protection of materials in the seabed sediment owing to the extensive development and utiliziation to marine. In this paper, the corrosion behaviour of mild steel were investigated with weight-loss and electrochemical measurements for understanding the corrosion behaviour and its mechanism. When there is no microbiologically influenced corrosion, the weight-loss shows the corrosion rate is lower in the SBS than them in other corrosion zone in marine. The corrosion rate of mild steel in the SBS falling into the sand type is higher one time than it in the SBS falling into the clay type. For knowing the corrosion behaviour, Liner polarizational resistance(LPR), potentiodynainic scanning in low polarization zone and electrochemical impedance spectra(EIS) measurements were come into use. The electrochemical parameters were fitted and calculated. The differences of the corrosion behaviour in sand and clay types were discussed. It was found that the diffusion rate of dissolved oxygen (DO) as depolarization agent in the cathodic zone determined the difference of corrosion rate in two kinds of types SBS. According to the results of fitting the datas in low polarization zone and EIS measurement, the corrosion mechanism of oxygen diffusion was put forward, the equivalent current and the corrosion model were proved and explained. In the paper, the corrosion behaviour of mild steel were studied all around, the low polarization curve fitting technique was applied in the first, and some significative results were accquired. Integrated the characters of EIS, the equivalent current and corrosion model was put forward.