Influence of inorganic anions from atmospheric depositions on weathering steel corrosion and metal release

摘要

The individual effects of nitrate, chloride and sulphate on weathering steel appearance, patina composition, corrosion rate and metal release (Fe, Cr, Mn, Cu, Ni) were investigated by accelerated ageing with anion solutions at environmental concentrations. The anions influence the growth and evolution of corrosion products in the following order: SO42- > Cl- > NO3-. Even though SO42- induces the highest kinetic in patina growth and metal release, it tends to passivate the alloy by suppressing both processes with increasing time and concentration. Cl-, conversely, does not induce any stabilization trend and seems to contribute more than the other anions to metal runoff. (C) 2019 Elsevier Ltd. All rights reserved.