Background: Potentiodynamic polarization experiments were performed
on Alloys IN601 and C22 to evaluate their susceptibility to localized corrosion in
hydrochloric acid (HCl) at pH2. The tested specimens were evaluated by auger
electron spectroscopy (AES) and scanning microscopy (SEM).
Nickel chromium alloys consist of surface oxide layers and corrosion products with
metallic materials beneath.
Methods: Electrochemical techniques are used to examine the pitting tendencies of
specimens of IN601 and C22 immersed in a concentrated hydrochloric acid solution
(pH2). Techniques include potentiodynamic anodic polarization to determine
the active-passive characteristics of alloys and scanning, X-ray, and Auger electron
spectroscopy to characterize specimen surfaces in terms of pitting morphologies and for surface
analysis of oxide layers.
Results: This paper examines the effect of HCl solution on the pitting behaviour of these alloys. Results
show that IN601 alloy was characterized by more pitting than C22.
Conclusion: There are deeper oxide layers and corrosion products formed on sample surfaces of alloys
C22 than in IN601. Furthermore, C22 exhibits a smaller hysteresis loop than IN601, thereby indicating
that it has no pitting corrosion in concentrated HCl than IN601.