Zhu Yongyan, Ding Jiayi, Zhang Jianli, Li Liang
Jiangsu Key Laboratory of Green Synthetic Chemistry for Functional Materials, School of Chemistry and Materials Science, Jiangsu Normal University, Xuzhou 221116, China.
Jiangsu Zhongneng Silicon Industry Technology Development Co., Ltd., Xuzhou 221116, China.
Materials (Basel). 2020 Nov 27;13(23):5392. doi: 10.3390/ma13235392.
In this paper, effects of sodium phosphate (NaPO) and sodium nitrite (NaNO) on the pitting corrosion of X70 carbon steel in 0.10 mol/L NaCl solution were investigated by potentiodynamic polarization technique, electrochemical impedance spectroscopy (EIS) method, scanning electron microscope (SEM) and scanning electrochemical microscope (SECM). The SECM equipment was used to observe the dynamic processes of the pitting corrosion in situ. NaPO or NaNO in the sodium chloride solution decreased the local anodic dissolution and increased the pitting resistance of the specimen. By analysis and comparison, it can be concluded that the inhibition effect of NaPO is mainly due to the formation of a salt film, while the corrosion inhibition of NaNO is principally attributed to a protective oxide film on the electrode surface.
本文采用动电位极化技术、电化学阻抗谱（EIS）法、扫描电子显微镜（SEM）和扫描电化学显微镜（SECM），研究了磷酸钠（NaPO）和亚硝酸钠（NaNO）对X70碳钢在0.10 mol/L NaCl溶液中点蚀的影响。利用SECM设备原位观察点蚀的动态过程。氯化钠溶液中的NaPO或NaNO降低了局部阳极溶解，提高了试样的耐点蚀性能。通过分析和比较可以得出结论，NaPO的缓蚀作用主要是由于形成了盐膜，而NaNO的缓蚀作用主要归因于电极表面的保护性氧化膜。
