纯Al在3种典型沿海、工业和乡村大气中的腐蚀行为

Characterization of Corrosion Products on Pure Al Exposed in Atmospheres at Typical Rural, Industrial and Coastal Areas in China

纯Al在沿海、工业以及乡村大气环境中暴露12个月之后,利用电化学阻抗谱技术(EIS)以及扫描电镜(SEM)研究腐蚀产物对纯Al大气腐蚀过程的影响。结果表明,纯Al在沿海环境中腐蚀最为严重,在工业环境中次之,在乡村环境中最轻。在沿海与工业环境中,纯Al表面形成了不同厚度的腐蚀产物层;在乡村环境中,只有少量腐蚀产物分散存在,未形成连续的腐蚀产物层。纯Al大气腐蚀的速率控制步骤在沿海环境中为扩散过程;在工业与乡村环境中为电荷转移过程。

Pure Al plates were exposed in different atmospheres for 12 months at three typical test sites respectively： i.e. a rural site at Xishuangbanna of Yunnan province, an industrial site at Ji- angjin of Sichuan province and a coastal site at Wanning of Hainan province. Then the corroded A1 plates were characterized by means of EIS technique and SEM. The results indicate that the corro- sion resistance of pure AI is the worst in the coastal atmosphere, the best in the rural atmosphere and the middle in the industrial atmosphere. Different thick layers of corrosion products were formed on A1 surface in the rural and industrial atmosphere. In the contrast, a few corrosion prod- ucts were formed dispersedly in the coastal atmosphere. The rate controlling step may be the diffu- sion of corrosive ions for the corrosion process in the coastal atmosphere, while the charge transfer for those in the rural and industrial atmospheres.