Classification and spatial mapping of atmospheric corrosion of China

Abstract Atmospheric corrosion is ubiquitous in China but varies a lot among different regions covering the cold, temperate, and tropical zones. Categorizing the atmospheric corrosivity and plotting precise atmospheric corrosion map remain key interest for a variety of industries. The present work proposed an atmospheric corrosion map of China for hot-dip galvanized steels, which was constructed by inverse distance weighting (IDW) interpolation algorithm based on both the measured corrosion rates of coupons exposed at 2393 inland test stations and calculated corrosion rates from a prevalent dose-response function in 2918 sites in coastal regions. When the corrosion category was used as the criterion, the IDW interpolation algorithm of power 2 performed best. Cross-validation results confirmed that the prediction accuracy of IDW interpolation reached 85.6%. Based on the corrosion map, the categories of atmospheric corrosivity in China could be determined.