Electrochemical techniques for determining corrosion rate of rusted steel in seawater

Corrosion rates of mild steel for long-term immersion were estimated by electrochemical and weight-loss methods The results showed that application of electrochemical methods yielded erroneous values The main reason was that beta-FeOOH produced after long-term immersion with high electrochemical activity in the inner rust layer exerted significant influence In electrochemical tests even small polarization can make beta-FeOOH participate in cathodic reaction which leads to overestimating corrosion rate In order to confirm it electrochemical behaviour was studied in aerated and deaerated conditions to investigate the effect of rust layers on reduction reaction After calibration the electrochemical measurement result was coincided with the weight loss (C) 2010 Elsevier Ltd All rights reserved