Evolution of atmospheric corrosion of MnCuP weathering steel in a simulated coastal-industrial atmosphere

► The evolution of corrosion of MnCuP weathering steel in a simulated coastal-industrial atmosphere was studied. ► Instantaneous corrosion rate was used to characterise the corrosion kinetics instead of average corrosion rate. ► The formation of β-FeOOH in the presence of Cl− can be affected greatly by the co-existence of SO42-. ► The increased relative amount of α-FeOOH in the rust layer indicates its improved corrosion resistance. ► The protective ability of the rust layer can be evaluated by the charge transfer resistance.