[Objective]Different content ratio of the rare earth La was added to analyze the electrochemical mechanism of the Al-Zn-In-Si based sacrificial alloy anode to get the La con-tent of sacrificial anode with the best electrochemical performance in the marine environ-ment.[Methods]The open circuit potential,working potential,dissolving morphology,current efficiency and polarization behavior of aluminium sacrificial anode containing La were tested by using of XRD analysis,polarization curves test,EIS test and constant current test in a sim-ulated marine environment.Additionally,the electrochemical mechanism of the anodes was also discussed.[Results]The existence form of solute elements in the aluminium sacrificial anodes was changed by adding La element that had different influence degree with different contents;the induction period and development period of pitting during the activation dissolution process of aluminium sacrificial anode with La were observed by EIS spectrums.Polarization curves showed that the corrosion potential of a-luminium sacrificial anode had become positive and the activity of decreases with excessive element La;the constant current test showed that the current efficiency of aluminium sacrificial anode had been improved after adding La.[Conclusion]The electrochemical performance of aluminium sacrificial anode are improved ef-fectively with proper addition of La element in seawater.The current efficiency of aluminium sacrificial anodes reach the peak while cotaining 0.2% La.%【目的】分析 Al-Zn-In-Si系牺牲阳极添加不同含量配比的稀土元素镧(La)时，其电化学性能的作用规律，获得在海水环境下最佳牺牲阳极电化学性能的 La 添加量。【方法】通过模拟海洋环境，采用 XRD 分析、极化曲线、交流阻抗(EIS)和恒电流加速试验等方法，研究含 La铝合金牺牲阳极的开路电位、工作电位、溶解形貌、电流效率以及极化等行为及其发生机理。【结果】La的加入改变了铝合金牺牲阳极溶质元素的存在形式，并随着含量的变化对其产生不同程度的影响；EIS谱表明含 La铝合金牺牲阳极活化溶解过程体现了点蚀诱导期和发展期，极化曲线表明加入过量 La后铝合金牺牲阳极的腐蚀电位变正，活化性能变差；恒电流测试实验表明加入 La后铝合金牺牲阳极的电流效率有所升高。【结论】适量添加稀土元素 La可有效改善铝合金牺牲阳极在海水中的电化学性能，其中 La含量为0.2%的铝合金牺牲阳极电流效率最高。
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