Evaluation method for corrosion depth of uncoated carbon steel and its time-dependence using thickness of corrosion product layer

Corrosion environments of each part in steel structures are often significantly different. Therefore, to maintain economically the structures, it is necessary to evaluate properly the environment and to predict the time-dependence of the corrosion damage. This research focused on comprehensively evaluating the corrosive environment of each part in paint coated steel structures using mean corrosion depth of uncoated steel plate mounted on the steel members. Atmospheric exposure tests were carried out on the uncoated specimens in four exposure sites where each corrosion environment is significantly different. Based on the test results, a high practical method of evaluating mean corrosion depth using the thickness of corrosion product layer of the mounted plates was proposed without removal of the corrosion product. In addition to this method, an evaluation method for time-dependence of corrosion depth of each part in the structures after the paint coating has deteriorated was also proposed.