New Apparatus and Evaluation Method for Salt Spray Tests

Salt spray tests have long been used in various industries to assess the corrosion resistance of materials. Observations of the corrosion process and evaluation of rusting conditions, which are critical in this test, often rely on manual operations and visual judgments. Therefore, this method suffers the following issues: a large burden on examiners, human error, and individual differences in evaluation. Herein, we propose a new apparatus that can automatically observe and quantify the rusting of metallic materials. The results of the practical evaluation of the apparatus showed that it allows to take clearer images of the corrosion process than the conventional test method. Furthermore, the test and observations are performed automatically. Analysis of the obtained images allowed to quantify changes in the rust area using certain criteria. We showed that the proposed apparatus could automatically obtain more detailed corrosion resistance data than conventional testers, revealing corrosion processes of materials that could not be captured by conventional methods.