Correlation between Passivity Breakdown and Composition of Passive Film Formed on Alloy 690 Studied by Sputtering XPS and FIB-HRTEM. Issue 12 (26th July 2019)

• Record Type: Journal Article
• Authors: Wang, Yicheng; Song, Shizhe; Wang, Jianqiu; Behnamian, Yashar; Xu, Likun; Fan, Hongqiang; Xia, Da-Hai
• Is Part Of: Journal of the Electrochemical Society. Volume 166:Issue 12(2019)
• Page Start: C332
• Page End: C344
• Publication Date: 2019-07-26
• Subjects: Anodic Films; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/2.1291912jes
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : Passivity film breakdown on steam generator (SG) tubing alloys in Cl − + S2 O3 2− solutions were investigated using a focused ion beam (FIB) and high resolution transmission electron microscopy (HRTEM), and a correlation between passivity film breakdown and film composition was established. Sulfur was not incorporated into the passive film that formed on the alloy. S2 O3 2− adsorbed on the passive film surface was subsequently electrochemically reduced caused by SG alloy, leading to selective dissolution of Ni from the passive film. Fe, Ni, and Cr in the passive film have complex effects on corrosion resistance, which is highly dependent on temperature, and the Cl − /S2 O3 2− concentration ratio.