动车组上铝合金安装底座的锈蚀分析

Analysis on corrosion of aluminum alloy mounting base used in electric multiple unit

针对动车组在运行过程中发现的铝合金安装底座的锈蚀情况,分别从材质和结构方面进行分析,初步推断铝合金底座的锈蚀原因。通过性能检测和抗锈蚀性能试验确定了锈蚀的主要原因是底座用的2A11铝合金易发生晶间腐蚀,与不锈钢支架接触时电偶腐蚀敏感性高,底座与支架之间的间隙会积存电解液。提出了多项整治措施,为类似安装底座的防锈蚀设计提供参考。

The causes for the corrosion of aluminum alloy mounting base found during the running of electric multiple unit were preliminarily deduced by analyzing the material and structure. Three main causes were determined based on property tests and corrosion tests:(1) the mounting base made of 2A11 aluminum alloy easily suffers from intergranular corrosion;(2) the galvanic corrosion sensitivity is high when mounting base is connected with the mounting bracket made of stainless steel;and (3) there exists electrolyte in the gap between the base and bracket. Some remedial measures were presented, providing a reference for the anticorrosion design of similar mounting base.