Abstract
Effects of immersion time on the passivation behavior and the pitting corrosion resistance of Ni70Cr21Si0.5B0.5P8C <= 0.1Co <= 1 (VZ1) and Ni72.65Cr7.3Si6.7B2.15C <= 0.06Fe8.2Mo3 (VZ2) glassy alloys in artificial seawater at different p11 values have been studied using electrochemical impedance spectroscopy, cyclic polarization, and electrochemical frequency modulation techniques. The corrosion rate of the VZ1 alloy at all studied pH values reaches a low level after about 14 d and, for the VZ2 alloy, after 2 d of immersion. The VZ1 alloy has a relatively lower value of passive current density and represents a smaller anodic hysteresis loop area compared with the VZ2 alloy. The effect of immersion time on corrosion potential, corrosion current density, pitting potential, and repassivation potential has been investigated and discussed.