By using polarization resistance measurement and electrochemical impedance spectroscopy (EIS)

in field corrosion electrochemical detections of Q235 carbon steel and Q235 ultrafine grained steel immersed samples in Zhoushan Marine Corrosion Test Station were performed for 4 years.Dynamic corrosion data during exposure were obtained.Electrochemical detection results reflected not only the corrosion modalities and corrosion rates of the samples

but also the direct influence of marine environmental factors on the corrosion behavior. Seawater temperature was the major factor influencing the corrosion behaviors of carbon steels

and corrosion rates of these samples increased with increasing seawater temperature.The influence of seawater velocity and orientation of flow was less than that of temperature.