Nickel base alloys are considered among candidate materials for engineered barriers of nuclear repositories. The localized corrosion resistance is a determining factor in the materials selection for this application. This work compares the crevice corrosion resistance of selected nickel base alloys, namely 625, G-30, G-35, C-22, C-22HS and HYBRID-BC1. The crevice corrosion repassivation potential (ER,CREV) of the tested alloys was determined by the Potentiodynamic-Galvanostatic-Potentiodynamic (PD-GS-PD) method. The testing temperature was 60ºC and the chloride concentrations used were 0.1 M, 1 M and 10 M.
A linear relationship between ER,CREV and the logarithm of chloride concentration was found. ER,CREV increased linearly with PREN (Pitting Resistance Equivalent Number) in concentrated chloride solutions. ER,CREV is the sum of three contributions: ECORR*, η and ΔΦ. ECORR* and η increased linearly with PREN, while ΔΦ increased linearly with PREN for concentrated chloride solutions, not showing a definite trend with PREN for the less concentrated solutions.