Prediction of long term corrosion (on several hundred years) of low alloy steels is a crucial issue in several research domains: metallic cultural heritage conservation, civil engeeniring, etc. Recent results demonstrate that, despite the corrosion layers could reach several millimetre thicknesses, the kinetics can be controlled at the nanoscale (presence of barrier layer at the metal/oxide interface, influence of crystallinity in the electrochemical reactivity, etc).