Synergistic effect of chloride and NO₂ on the atmospheric corrosion of bronze

PurposeThe purpose of this paper is to investigate the effect of chloride along with NO2 on the atmospheric corrosion of bronze using exposure tests.Design/methodology/approachSurface tension tests and electrochemical impedance measurements together with scanning electron microscopy (SEM) with energy dispersive atomic X‐ray, and X‐ray diffraction are used to characterize the corrosion behavior.FindingsThe results of the weight loss measurements show that the whole corrosion kinetics can be described approximately by: ΔW=atb; the synergistic effect of chloride and NO2 is observed clearly, though no nitrate existed in the corrosion products.Originality/valueA new catalyst theory has been suggested in this paper, i.e. that NO2 acts as a catalyst during the corrosion process when significant quantities of chloride also are present.