杂环化合物对热浸镀锌铝合金镀层在稀盐酸中的缓蚀作用

Corrosion inhibition of hot dipping Zn-Al alloy coated steels by heterocyclic compounds in diluted HCl solutions

为找到在热浸镀钢材表面清洗处理过程中替代铬酸使用的缓蚀剂,通过质量损失测试、电化学测试和扫描电镜分析等方法研究了烟酸、吖啶和小檗碱对热浸镀5%铝?锌和55%铝?锌合金镀层在盐酸介质中的缓蚀作用。结果表明,3种杂环化合物在盐酸介质中对两种锌铝合金镀层均具有良好的缓蚀作用,其中小檗碱的缓蚀作用最好;它们通过单分子层、化学吸附方式吸附在镀层表面从而阻滞酸液对镀层的腐蚀,其吸附遵从Langmuir吸附等温式。在盐酸介质中,烟酸、吖啶和小檗碱对5%铝?锌和55%铝?锌合金镀层钢材均为有效的环境友好型缓蚀剂。

In order to find chromate-substituting inhibitor in finishing process of hot dipping coated steels, the inhibition effects of nicotinic acid, acridine and berberine on the corrosion of hot dipping 5% Al-Zn and 55% Al-Zn alloy coated steels in diluted HCI solution were investigated using mass loss test, electrochemical measurement, and scanning electronic microscope analysis. The results indicate that these three heterocyclic compounds, especially berberine, can act as good inhibitors for both kinds of Zn-Al alloy coatings in HCI solutions, These compounds can adsorb on the coating surface by chemical adsorption with single molecular layer by following Langmuir adsorption isotherm. Nicotinic acid, acridine and berberine, therefore, are effective and environmental friendly corrosion inhibitors for 5%Al-Zn and 55%Al-Zn alloy coated steels in diluted HCI solutions.