Electrochemical Characterization of UNS N08367 and UNS S31603 Alloys in Presence of Chloride and Bromide Solutions

• Main Authors: Maya Visuet, Enrique, Karayan, Ahmad Ivan, Lopez, Homero Castaneda
• Format: Conference Proceeding
• Language: English
• ISSN: 1938-5862; 1938-6737
• DOI: 10.1149/05031.0227ecst

This work presents the interfacial characterization of two UNS corrosion resistance alloys (CRAs), N08367 and S31603 in LiCl and LiBr solutions. The electrochemical nature of these materials in halide solutions demonstrates different mechanisms at the substrate-electrolyte interface. Time and frequency domain electrochemical techniques were used; cyclic polarization tests showed that S31603 was attacked by pitting corrosion for different LiCl and LiBr concentrations. N08367 revealed different mechanisms due to the passivation layer existed under polarization conditions. The current densities increments for the N08367 alloy were attributed to the charge transfer-adsorption mechanism, as evidenced by the EIS data. The pitting potentials of S31603 in LiCl and LiBr solutions were similar. However, the current transients were only found in S31603 in LiCl which might indicate that LiCl had more significant kinetic effect than LiBr. Bias potential was applied for EIS testing to support either active/passive/transpassive behavior for each material. Qualitative analysis could demonstrate the link between EIS and polarization techniques.