Effect of Acid Fog on Rust Formation and Fatigue Strength of Weathering Steel

산성안개가 내후성강재의 녹형성 및 피로강도에 미치는 영향

The purpose of this study is to investigate the effect of acid fog on the rust formation behavior of weathering steel (SMA50) which is used in uncoated bridges. Weathering steel didn't form the passive film under the environment of acid fog(pH5,6), whereas the environment of distilled water formed the protective oxide film. Therefore, the construction of weathering steel under the environment extremely exposed to SOx and NOx which are the main compositions of acid fog is not adequate. Fatigue limits of weathering steel under acid fog environment are remarkably decreased as compared with environment of distilled water. The corrosive constituents in acid fog has piled up the corrosion products on specimen surface and generated the corrosion pits. Because of the high stress concentration arising at this corrosion pit, relatively low fatigue limits were obtained for acid fog specimens.