Application of electrical resistance method to analysis of corrosion behavior under atmospheric corrosion environment

摘要

© 2016, Japan Society of Corrosion Engineering. All rights reserved.Corrosion monitoring using an electrical resistance (ER) technique is considered to be the most suitable method for evaluating change of corrosion rates of a steel due to change of atmospheric conditions. In this study, exposure tests of steels in Okinawa and Kawasaki confirmed that changes of a corrosion rate throughout a year can be evaluated in detail by the ER technique. Furthermore, it was indicated that the relationship between the corrosion rate and environmental factors (temperature, relative humidity, amount of airborne sea salt, etc.) could be analyzed in detail by the ER technique. The accuracy of the technique was confirmed by comparison of the corrosion losses evaluated by the ER technique with those of test specimens. Based on the results, the accuracy of the corrosion rate evaluated by the ER sensor was higher than that by the conventional ACM (Atmospheric Corrosion Monitoring) sensor. The cause of the lower accuracy of ACM sensor is thought to be that the ACM output has very low sensitivity against temperature, notwithstanding that actual corrosion rate has high sensitivity.