Al-Zn-In-Si牺牲阳极在不含/含硫酸盐还原菌海泥环境中的电化学性能研究
Study on the Electrochemical Performance of Al-Zn-In-Si Sacrificial Anode in Sea Mud Environment with/without Sulfate Reducing Bacteria

目的：分析A13型Al-Zn-In-Si牺牲阳极在不含/含硫酸盐还原菌海泥环境中的电化学性能。方法：进行4天强制电流标准试验，采用扫描电子显微镜(SEM)、能谱分析(EDS)及三维超景深显微镜分析牺牲阳极腐蚀特征及表面元素含量的变化，对比研究了A13型Al-Zn-In-Si牺牲阳极在不含与含硫酸盐还原菌海泥环境中的电化学性能。结果：不含SRB海泥环境中牺牲阳极的电化学容量和电化学效率分别为1908.77 Ah/kg和66.78%，满足相关标准要求；而含SRB海泥环境中牺牲阳极的电化学容量和效率仅为1238.67 Ah/kg和43.33%，不满足牺牲阳极阴极保护在海泥环境下的设计标准。同时，含SRB海泥环境中铝阳极表面形成了大量密集分布的腐蚀坑洞，表现为典型的不均匀腐蚀特征，最大腐蚀深度达到1230 μm，约是不含SRB海泥环境中铝阳极腐蚀坑深(约300 μm)的4倍。结论：在含有SRB海泥环境中，A13型Al-Zn-In-Si牺牲阳极电化学容量和效率仅为1238.67 Ah/kg和43.33%，已经不能满足阴极保护设计标准要求。因此，在海泥环境中铝牺牲阳极的应用必须充分关注SRB这一因素，尤其是铝牺牲阳极需要长周期服役于海泥环境中的情况。
Objective: To analyze the electrochemical performance of A13 type Al-Zn-In-Si sacrificial anode in sea mud environment without/with sulfate reducing bacteria. Methods: A 4-day forced current standard test was conducted. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and three-dimensional ultra-depth-of-field microscopy were used to analyze the corrosion characteristics of the sacrificial anode and the changes in surface element content. A comparative study was conducted on the electrochemical performance of A13 type Al-Zn-In-Si sacrificial anode in marine mud environments without and with sulfate reducing bacteria. Re-sults: The electrochemical capacity and electrochemical efficiency of the sacrificial anode in an SRB-free sea mud environment were 1908.77 Ah/kg and 66.78% respectively, meeting the re-quirements of relevant standards; while the electrochemical capacity and efficiency of the sacrificial anode in an SRB-containing sea mud environment were only 1238.67 Ah/kg and 43.33%, which do not meet the design standards of sacrificial anode cathodic protection in marine mud environment. At the same time, a large number of densely distributed corrosion pits were formed on the surface of the aluminum anode in the SRB-containing sea mud environment, showing typical uneven corrosion characteristics. The maximum corrosion depth reaches 1230μm, which is approximately 4 times the depth of the aluminum anode corrosion pit in an SRB-free sea mud environment (about 300 μm). Conclusion: In an environment containing SRB sea mud, the electrochemical capacity and efficiency of the A13-type Al-Zn-In-Si sacrificial anode are only 1238.67 Ah/kg and 43.33%, which cannot meet the cathodic protection design standard requirements. Therefore, the application of aluminum sacrificial anodes in marine mud environments must pay full attention to the factor of SRB, especially when aluminum sacrificial anodes need to serve in the marine mud environment for a long period of time.