Zn粉含量及表面沾污对环氧富Zn漆电化学行为的影响

采用腐蚀电位、电化学阻抗谱(EIS)评价了Zn粉含量以及涂层／基体界面污染程度对环氧富Zn涂层的防腐蚀性能的影响并探索了富Zn涂层的失效机制。实验结果表明，当涂层中Zn含量较少时，Zn粉没有有效的阻挡作用。通过对可能的阻抗模型的分析，认为富Zn涂层的电化学阻抗谱的低频段是由Zn^2 从金属表面穿过腐蚀产物的扩散控制。涂层／基体界面污染不仅影响了环氧富Zn涂层的防腐蚀性能的发挥，也加速了钢铁基体的腐蚀。

Influence Of Zinc Content And Surface Contamination On The Electrochemical Behaviors Of Epoxy Zinc--Rich Primer

The effect of zinc powder content and contamination of epoxy zinc-rich primer/substrate interface on the protective performance of the zinc-rich coatings was investigated by means of electrochemical impedance spectroscopy (EIS) and corrosion potential monitoring . The degradation mechanism of the zinc-rich coatings was elucidated . It was shown that effective barrier can not be formed in the coatings with low zinc content. The attack of zinc particles in zinc-rich coatings is explained in terms of diffusion control through the film of zinc corrosion products around the zinc particles. The surface contamination of the substrate is vital to the performance of the organic coatings protecting the substrate steel. The surface contamination will lead to not only the impairment of the performance of the zinc-rich coatings but also the acceleration of the degradation processes of the steel substrate.