In this study, the microstructure and corrosion behavior of hot-dipped Zn–6Al–3Mg alloy coating in Cl-containing environment were studied. The results show that there are primary Zn phase, Al-rich phase and ternary eutectic phase in the coating. Electrochemical corrosion occurs due to the formation of micro-electric couples between dendrites and ternary eutectic. The corrosion process can be divided into four stages, including the dissolution of the oxide layer, the corrosion of the coating microstructure, the covering of the corrosion products and the formation of the stable corrosion product layer. In addition, electrochemical tests demonstrated that the active areas on the coating gradually decrease upon extending the corrosion time. The corrosion products protect the coating and improve its corrosion resistance.

中文翻译：

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含氯环境中热浸镀Zn-6Al-3Mg合金镀层组织及腐蚀行为研究

本研究研究了热浸镀Zn-6Al-3Mg合金镀层在含Cl环境中的显微组织和腐蚀行为。结果表明，镀层中存在初生Zn相、富Al相和三元共晶相。电化学腐蚀是由于枝晶和三元共晶之间形成微电偶而发生的。腐蚀过程可分为氧化层溶解、镀层微观结构腐蚀、腐蚀产物覆盖和稳定腐蚀产物层形成四个阶段。此外，电化学测试表明，随着腐蚀时间的延长，涂层上的活性面积逐渐减少。腐蚀产物保护涂层并提高其耐腐蚀性能。