Electrochemical characterization of low carbon steels during long term immersion in natural seawater

The corrosion behaviour of two low carbon steels immersed in natural seawater for up to three years was studied. In particular, the aim of this work was to investigate localized corrosion through controlled long-term laboratory tests. Electrochemical techniques, especially galvanic coupling corrosion current measurements and monitoring of open circuit potentials with time, associated with weight loss measurements and penetration rates determinations were use to evaluate the effect of the seawater temperature. The use of preventive and curative chlorination was also investigated. Finally Scanning Electron Microscopy coupled with X-EDS analyses and micro-Raman spectroscopy were used to characterize the corrosion products obtained under the various exposure conditions.