SECM in situ investigation of corrosion and self-healing behavior of trivalent chromium conversion coating on the zinc

被引：13

作者：

Feng, Jiqiang ^{[1
,2
]}

Wang, Youbin ^{[1
,2
,5
]}

Lin, Xueliang ^{[1
,2
]}

Bian, Meihua ^{[3
]}

Wei, Yuezhou ^{[4
]}

机构：

[1] Guangxi Univ, Sch Resources Environm & Mat, State Key Lab Featured Met Mat & Life Cycle Safety, Nanning 530004, Peoples R China

[2] Guangxi Univ, Educ Dept Guangxi Zhuang Autonomous Reg, Key Lab High Performance Struct Mat & Thermo Surfa, Nanning 530004, Peoples R China

[3] Elect Power Res Inst Guangxi Power Grid Co Ltd, Nanning 530004, Peoples R China

[4] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China

[5] Guangxi Univ, State Key Lab Featured Met Mat & Life cycle Safety, Nanning 530004, Peoples R China

来源：

SURFACE & COATINGS TECHNOLOGY | 2023年 / 459卷

基金：

中国国家自然科学基金;

关键词：

Trivalent chromium conversion coating; Localized corrosion; SECM; Polyaniline; SCANNING ELECTROCHEMICAL MICROSCOPY; DIP GALVANIZED STEEL; DEGRADATION PROCESSES; REDOX-COMPETITION; CHROMATE; ZN; PERFORMANCE; PROTECTION; ALKALINE; FILM;

D O I：

10.1016/j.surfcoat.2023.129411

中图分类号：

TB3 [工程材料学];

学科分类号：

0805 ; 080502 ;

摘要：

The trivalent chromium conversion coating (CCC) is prepared on pure zinc, and the corrosion resistance of trivalent CCC is characterized by scanning electron microscopy (SEM), polarization curves and electrochemical impedance spectroscopy (EIS). The local corrosion and self-healing behavior of trivalent CCC at the initial stage of immersion corrosion are investigated in situ by scanning electrochemical microscopy (SECM). The results show that trivalent CCC has higher impedance value and lower corrosion current density as compared to pure zinc, and the coating has excellent corrosion protection for pure zinc. At the initial stage of corrosion (0-12h), the SECM feedback current of the trivalent CCC does not change significantly; after immersed for 24 h, the local current rises from 0.83 to 0.95, which can be explained that the trivalent CCC cracks locally and occurs local corrosion. In situ analysis of oxygen concentration at the scratch of trivalent CCC indicates that the addition of polyaniline can inhibit the oxygen reduction reaction, which hinders the corrosion process and improves the self-healing ability of trivalent CCC.

引用

页数：13

共 54 条

[1] Computational, kinetic, and electrochemical studies of polyaniline functionalized ZnO and ZnO-SiO2 nanoparticles as corrosion protection films on carbon steel in acidic sodium chloride solutions [J].