Use of the gold markers method to predict the mechanisms of iron atmospheric corrosion

Iron corrosion under atmospheric conditions has been investigated by using the gold markers method. The corrosion experiments were performed in a climatic chamber with an accelerated treatment. The gold markers localization, carried out by scanning electron microscopy coupled with energy dispersive X-ray spectroscopy, revealed that the rust layer growth was essentially due to an internal development. Moreover, microRaman mappings allowed prediction of the mechanism of rust layer evolution during the ageing treatment. Finally these results were compared to samples corroded for several 100 years in order to extrapolate our observations to long term corrosion.

► Corrosion mechanisms investigated by gold markers method coupled with microRaman imaging.
► Experimental highlighting of an important internal development of the rust layer.
► Microstructural evolution of the corrosion product layer during atmospheric treatment.
► Comparison with long-term corrosion layer microstructure.