Alloy 22 (N06022) is highly resistant to localized corrosion. Under aggressive environmental
conditions Alloy 22 may be susceptible to crevice corrosion in hot chloride (Cl-) solutions.
The objective of the present work was to explore the environmental and geometrical
conditions for crevice corrosion to occur. Electrochemical tests were performed using PCA
and prismatic mill annealed Alloy 22 specimens in chloride solutions. Crevice corrosion current
density was found to be a function of applied potential. iCREV values ranged from
40 µA/cm2 to 20 mA/cm2. Such low values of current density explained the absence of pitting
corrosion in Alloy 22 at any potential. Decreasing of the effective diffusion distance in a propagating
crevice is thought to cause crevice corrosion stifling or repassivation after long anodic
polarization. Crevice corrosion breakdown potential is expected to decrease with potential
scan rate, approaching repassivation potential for low scan rates. The lowest corrosion potential
of Alloy 22 in hydrochloric acid solutions at which active corrosion exists was proposed as
the lowest possible repassivation potential for crevice corrosion.