The pitting corrosion of amorphous Ni63Cr12.5Fe4Si8B12.5 alloy in chloride solution

Abstract The pitting corrosion behavior of amorphous Ni 63 Cr 12.5 Fe 4 Si 8 B 12.5 alloy in NaCl solution was studied using electrochemical methods. Hemispherical pits were found to initiate along mechanic polishing lines on the surface. Electropolishing improved pitting resistance greatly. Potentiostatic anodic polarization tests showed an incubation time for pit nucleation after which the pits propagated very quickly. The poor pitting resistance of this amorphous alloy was ascribed to its repassivation characteristics.