Abstract
The rust formed on the 0.2 mass%Ru-bearing steel was analyzed by EPMA and XPS after wet/dry corrosion test using chloride solution. The Ru-enriched layers were found in the rust of the Ru-bearing steel, and the number of such layers were almost the same as those of test cycles. It is shown that Ru is zerovalent (metal) state at the Ru-enriched layer in the rust by EPMA and XPS. Ru ion could be dissolved into the solution with the ferrous ion from the base metal in wet process, and finally carried to around the interface of the outer and inner laylers due to the decrease of the water film in dry process, then Ru could become the metal state which was stable in this site in the iron rust.
