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 and discriminate between
electrochemical and biological processes. Electrochemical techniques, especially galvanic
coupling corrosion current measurements and monitoring of open circuit potentials with
time were used to evaluate the effect of the seawater temperature. Associated weight loss
measurements and penetration rates were also determined. The application of preventive
and curative chlorination, as well as the use of acid cleanings, was also investigated.
Finally, the corrosion layer of a specimen immersed for more than one year in ambient
natural seawater was characterized using micro-Raman spectroscopy.
Keywords: Carbon steel, localized corrosion, seawater, magnetite