Alloy 22 is a Ni-based alloy that exhibits an excellent uniform and localized corrosion resistance due to its protective passive film. Alloy 22 is extremely resistant to the various modes of aqueous corrosion over broad ranges of temperature, pH, and concentration of anionic and oxidizing species. Alloy 22 is one of the candidate materials for the construction of corrosion-resistant barriers of high-level nuclear waste containers. Electrochemical tests such as Cyclic Potentiodynamic Polarization (CPP) tests and Electrochemical Impedance Spectroscopy (EIS) were performed to study the corrosion behavior of Alloy 22 in 0.01M, 0.1 M, lMNaCl solutions, at alkaline pH values at 90"C. The aim of this research was to determine if silicate ions would inhibit crevice corrosion in a fashion similar as sulfate and notable nitrate. Results show that crevice corrosion was inhibited in solutions with pH > 12.5. The inhibition effect was attributed to the high solution pH and not to the presence of silicate. At a given pH, inhibition was independent of the ratio R - [OlfJ/fCrj. The uniform corrosion rate after 24-hour of immersion in alkaline solutions was low and independent of environmental variables, such as pH and anion concentration.
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