摘要
通过动电位极化、电化学阻抗谱、Mott-Schottky等电化学测试方法和SEM、EDS等表面分析技术,研究了受交流电干扰的316L不锈钢钢筋在含3.5%(质量分数)氯离子的模拟混凝土孔隙液中的腐蚀行为.结果表明:交流干扰下,316L试样的自腐蚀电流密度增加,试样表面形貌由保护性的致密状变为非保护性的起皮疏松状,颗粒状腐蚀产物明显增多;交流干扰降低了钝化膜的保护性能,膜电阻大幅降低,膜点缺陷数量增加,促进了腐蚀性介质的侵蚀,耐腐蚀性及钝化性降低;试样已形成的钝化膜暴露在交流干扰下时具有临界交流电压,超过临界电压后钝化膜发生机电击穿,试样的腐蚀电位和交流电流密度发生突变;交流干扰促进了试样的点蚀,点蚀数量和强度均大幅增加.
The corrosion behavior of 316L stainless steel bars interfered by AC in the pore liquid of simulated concrete containing 3.5%was studied through electrochemical testing methods such as potentiodynamic polarization,electrochemical impedance spectroscopy,Mott-Schottky,and surface analysis techniques such as SEM/EDS.The results show that:under AC interference,the self-corrosion current density of the 316L sample increases,the surface morphology of the sample changes from a protective dense shape to a non-protective peeling loose shape,and the granular corrosion products increase significantly;the AC interference reduces bluntness the protective performance of the film,the film resistance is greatly reduced,the number of film point defects increases,which promotes the corrosion of corrosive media,and the corrosion resistance and passivation are reduced.When the passive film formed on the sample is exposed to AC interference,there exists a critical AC voltage.Once the AC voltage exceeds this critical value,electromechanical breakdown of the passive film occurs,and the corrosion potential and AC current density of the sample change abruptly.AC interference promotes the pitting corrosion of the sample,and the number and intensity of the pitting corrosion are greatly increased.
作者
许亚男
闫茂成
刘瑕
XU Yanan;YAN Maocheng;LIU Xia(Shenyang University of Chemical Technology,Shenyang 110142,China;Institute of Metal Research,Chinese Academy of Sciences,Shenyang 110016,China)
出处
《沈阳化工大学学报》
2024年第5期408-417,共10页
Journal of Shenyang University of Chemical Technology
关键词
交流干扰
316L不锈钢
模拟混凝土孔隙液
钝化膜
点蚀
AC interference
316L steel rebar
simulate concrete pore fluid
passive film
corrosion pitting
