镀层合金与碳钢基底的电偶腐蚀研究

【目的】为寻求钢基底最佳抑制电偶腐蚀的热浸镀层材料,研究2种镀层合金与碳钢组成的电偶是否发生危害极大的极性逆转现象。【方法】选择Zn-55%Al-1.6%Si合金和Zn-5%Al-0.2%RE合金,分别与碳钢组成耦合电极,测试其在天然海水及不同浓度Cl-介质中的电偶电流等。【结果】海水体系以及Cl-浓度为0.005%,0.01%,0.5%体系中,2种镀层合金与碳钢组成的电偶均未出现极性逆转现象。对于同一种镀层合金与碳钢组成电偶,其偶合电流在不同浓度的Cl-中电流值不同,随着Cl-浓度的增加,其偶合电流也增加。【结论】钢基底热浸镀Zn-55%Al-1.6%Si合金或Zn-5%Al-0.2%RE可以有效抑制电偶腐蚀。

Galvanic Corrosion Study of Surface Coating and Steel Substrate

Objective] In this paper, in order to study whether the polarity reversal phenomenon is occurred after the damage of the hot-dipped coating.Methods] The coupling electrodes were composed of Zn-55%Al-1.6%Si alloy, or Zn-5%Al-0.2%RE and alloyed with carbon steel. The galvanic current was tested in natural seawater and medium with different Cl^- concentrations to study the possibility of polarity reversals.Results] The experimental results show that the galvanic couple composed with two kinds of coating alloys and carbon steel did not occur the polarity reversal phenomenon in all the experimental conditions.Conclusion] The coupling current value of the galvanic couple composed with the same coating alloy and carbon steel was different in different Cl^- concentrations medium. With the increase of the Cl^- concentration, the coupling current was increased.