模拟污损生物附着对Zn-Al-Cd阳极腐蚀性能影响的研究

Corrosion of Zn-Al-Cd Sacrificial Anode in Simulating Marine Fouling Organisms Environment

通过电化学阻抗(EIS)、扫描电镜(SEM)和模拟生物膜方法研究污损生物附着对Zn-Al-Cd牺牲阳极在海水中腐蚀行为的影响.电化学阻抗结果得出,在整个实验周期内,阳极试样的腐蚀速率顺序为:添加微量藤壶牡蛎粉末<<表面涂一薄层琼脂的阳极<空白阳极;SEM结果表明,只添加薄层琼脂的Zn-Al-Cd发生均匀腐蚀,而添加微量藤壶牡蛎粉末的阳极发生局部腐蚀.整个实验结果可以说明,阳极表面大型污损生物的致密覆盖使内外腐蚀介质的交换受到抑制,在一定程度影响了Zn-Al-Cd牺牲阳极的溶解释放,影响阴极保护效果.但另一方面,大型污损生物在阳极表面形成的致密层也有可能引起局部腐蚀的发生.

The effects of marine fouling organisms on corrosion of Zn-A1-Cd sacrificial anode are investigated by u- sing electrochemical impedance spectroscopy （ EIS）, scanning electron microscopy （SEM） and artificial biofilm sim- ulation. The EIS results show that the corrosion rate of samples coated with oysters and barnacles powder is much smaller than samples coated only with agar. The results of SEM show that uniform corrosion occurs on the surface of Zn-A1-Cd samples coated with agar, while local corrosion occurs on the surface of samples coated with powder of barnacles and oysters. We conclude from the experiment that the existence of large fouling organisms inhibits the exchange of corrosion medium, and affects the cathodic protection efficiency. However, it perhaps can cause the lo- cal corrosion.