On the mechanisms of the corrosion of weathering steel by SO2 in laboratory studies: influence of the environmental parameters

We report here on the mechanisms underlying the corrosion of weathering steel in accelerated laboratory tests using artificially polluted SO2-atmospheres. The role of corrosion parameters such as the SO2 concentration, the exposure time, the relative humidity and temperature of the environment are discussed in detail. Through the extensive use of Mössbauer spectroscopy in both its transmission and electron detection modes, as well as with the help of other analysis techniques, the characterization of the different corrosion products at the various stages of the corrosion process has been carried out. The results complement the data obtained in field studies and help to understand the mechanisms involved in this complex phenomenon.