Electrochemical behaviour of Fe-based metallic glasses in acidic and neutral solutions

The corrosion behaviour and passive films of the FeCrMnMoWBCSi metallic glasses were investigated in acidic and neutral solutions using electrochemical measurements, AFM, and XPS. The alloys exhibit high corrosion resistance in H2SO4 and NaCl solutions in contrast with Na2SO4 and HCl solutions, respectively. In sulphate solutions, the film composition plays a key role in corrosion resistance and the films in H2SO4 solutions enrich low-valence Cr(III) and Mo(IV) species on the surface. In chloride solutions, the stability of the films depends on their structural properties. Possible mechanisms related to HSO4-/SO42- ions adsorption and Cl− ions penetration are also proposed.

► The corrosion resistance in H2SO4 solutions is better than in Na2SO4 solutions.
► In sulfate solutions, film composition plays a key role in corrosion resistance.
► The corrosion resistance in NaCl solutions is better than in HCl solutions.
► In chloride solutions, the stability of the passive film depends on structural properties.
► Mechanisms on the HSO4-/SO42- adsorption and Cl− penetration are proposed.