沉船原址保护金属框用两种Al-Zn-In系牺牲阳极的电化学性能及其影响因素

Electrochemical Property of Two Al-Zn-In Aluminum Alloy Sacrificial Anodes Used for Conservation of Shipwreck and Its Influence Factors

从化学成分、显微组织、腐蚀形貌和自腐蚀行为等方面探讨了两种用于古沉船原址保护金属框阴极保护的Al-Zn-In系牺牲阳极在自放电性能上产生差异的主要原因。结果表明:相较于2号铝合金牺牲阳极,1号铝合金牺牲阳极具有更高的电流效率。铝合金腐蚀速率、表面腐蚀产物脱落行为不会对两种牺牲阳极的自放电性能产生明显影响,2号铝合金牺牲阳极在腐蚀过程中明显的晶粒脱落是导致其自放电性能明显下降的主要原因,这一现象可能与晶界处富Ti沉积相的存在有关。

In terms of chemical composition,microstructure,corrosion morphology and self-corrosion behavior,the main reasons for the difference in self-discharge performance of two Al-Zn-In sacrificial anodes used for the cathodic protection of the metal frame of an ancient shipwreck in-situ protection were discussed.The results show that:compared with No.2aluminum alloy sacrificial anode,No.1aluminum alloy sacrificial anode had higher current efficiency.The corrosion rate of aluminum alloy and the shedding behavior of surface corrosion products would not significantly affect the self-discharge performance of the two sacrificial anodes.The obvious grain shedding of No.2 aluminum alloy sacrificial anode during the corrosion process was the main reason for the obvious decline of its selfdischarge performance.This phenomenon might be related to the existence of Ti-rich deposition phases at the grain boundaries.