Abstract
From research concerning to atmospheric corrosion, it is understood a little that rust differs with anions in water films, pH, wet-dry conditions, etc. But, there are many unknown parts in the growing process of rust. In order to study the relationship between corrosive factors and corrosion products, wet-dry cycle tests using several kinds of solutions were carried out.
Weathering steel was used as a specimen material. Corrosion products were investigated under parameters of the kind of solutions, water film thickness, solution concentration, etc.
As a result, it was observed for the easier generation of α-FeOOH than γ-FeOOH in the Na2SO4 solution, which depended on the solution concentration and water film thickness, etc. 1) α-FeOOH was mainly produced under water film which contained the 0.1mol/m3 Na2SO4 or more. 2) γ-FeOOH was produced under water film of less than 0.1mol/m3 Na2SO4 in a solution and in the drying process of water film.
