Protectiveness of Rust Formed on Conventional Weathering Steel

摘要

The influence of the chloride deposition on the protectiveness of rust formed on conventional weathering steel exposed to a rural environment for 41 years was examined. Amount of dissolved ferrous ions was enhanced when the deposited NaCl was over critical amount. At the same time, enrichment of Cl ions was seen at the inner layer of the rust, especially at the rust /steel interface. It was found that the reactivation of corrosion was strongly associated with the migration of Cl ions in the rust layer. Change in the structure of the rust was hardly seen. It is suggested that the inner layer of the rust originally has anion selectivity.