(1. 中国科学院 金属研究所,沈阳 110016;
2. 广东电网公司 电力科学研究院,广州 510080)
摘 要: 利用自制的降雨喷淋装置模拟Zn在酸雨条件下的大气腐蚀行为,采用扫描电镜(SEM)、X 射线能谱(EDS)、X 射线衍射(XRD)和电化学测试技术分别研究Zn腐蚀48、96、144、192和240 h后的腐蚀产物成分、锈层截面形貌以及表面锈层的电化学特性,分析了锈层对Zn腐蚀行为的影响。结果表明:主要的腐蚀产物为Zn(OH)2、ZnSO4、Zn4SO4(OH)6·3H2O和Zn5(OH)8Cl2·H2O;腐蚀过程中,Zn的表面形成了具有较好保护性的锈层,随着腐蚀时间的延长,锈层对Zn的保护作用先增强后减弱。
关键字: 模拟酸雨;大气腐蚀;腐蚀产物;电化学技术
(1. Institute of Metals Research, Chinese Academy of Sciences, Shenyang 110016, China;
2. Electric Power Research Institute, Guangdong Power Grid Corporation, Guangzhou 510080, China)
Abstract:The corrosion behavior of Zn in simulated acid rain atmospheric environment was studied with a simulating raining system self-designed, which can control rainfall and pressure close to the actual level. After zinc corroded in simulated acid rain atmospheric environment corrosion time of 48, 96, 144, 192 and 240 h, the morphologies and the composition of corrosion products, cross section of rust layers and the electrochemical characters of rust layers were investigated by scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), X-ray diffractometry (XRD) and electrochemical techniques. The results show that the corrosion products formed on the surface of zinc have good protection, but the degree of protection is limited, with the main product components for Zn(OH)2, ZnSO4, Zn4SO4(OH)6·3H2O and Zn5(OH)8Cl2·H2O. The protective effect of the rust layers is first enhanced, and then weakened as increasing the corrosion time.
Key words: simulated acid rain; atmospheric corrosion; corrosion products; electrochemical technique;