摘要
海军航空装备的快速发展导致飞机必将面临更为严峻的海洋大气腐蚀问题,而军用飞机紧固件的腐蚀,尤其电偶腐蚀将严重影响飞机结构的安全性水平.因此,本文采用盐雾腐蚀模拟、扫描电镜观察与分析、电化学测试分析（自腐蚀电位测试、动电位极化测试、电偶腐蚀电流测试）等试验研究方法,将航空装备常用的30CrM nS iA镀镉钝化螺栓与三种不同螺母（30CrM nS iA镀镉钝化螺母、30CrM nS iA镀锌钝化螺母和0Cr16Ni6钝化螺母）偶接装配,研究由于装配导致的电偶腐蚀效应对典型螺栓/螺母紧固件腐蚀行为的影响.结果表明,在三种不同组合装配中,30CrM nS iA镀镉钝化螺栓与0Cr16Ni6钝化螺母之间电位差最大,电偶腐蚀电流密度最高,对应螺栓电偶腐蚀敏感性评级达到E级,电偶腐蚀作用促进了镀镉钝化螺栓基体表面点蚀的扩展,腐蚀进程被加速,加速系数AF达到3.4;30CrM nS iA镀镉钝化螺栓与30CrM nS iA镀锌钝化螺母之间电偶效应则较弱,且螺母为电偶腐蚀阳极,腐蚀进程被加速,加速系数AF为1.2,电偶腐蚀敏感性评级为D级;相比上述两种组合,30CrM nS iA镀镉钝化螺栓与30CrM nS iA镀镉钝化螺母之间电偶效应最不明显,对应电偶腐蚀敏感性评级为A级.
Due to the rapid development of naval aviation equipment,naval aircraft will encounter complicated atmospheric corrosion problems resulting from exposure to the oceanic atmosphere. The corrosion of the fasteners in the aircraft,especially due to the galvanic corrosion between fasteners,seriously compromises the safety of a particular component in an aircraft. When an aircraft is used for a long duration in an oceanic atmosphere containing high humidity and salinity,a layer of liquid film having a thickness of less than1 μm will form on the surface of the structure,which causes electrical conduction between different structures,thereby increasing the risk of galvanic corrosion. Currently,many studies mainly focus on investigating the stress corrosion cracking（SCC） of bolt or galvanic corrosion between the bolt and aluminum alloy plates. However,only a few studies have investigated the galvanic corrosion of bolt/nut in assembly. Therefore,three types of nuts（Cd-plated 30CrMnSiA,Zn-plated 30CrMnSiA,and passivated 0 Cr16 Ni6） were utilized in this study,which were assembled to a Cd-plated 30CrMnSiA bolt. The salt-spray corrosion simulation,observations from scanning electron microscope（SEM）,and electrochemical measurements（open circuit potential,potentiodynamic polarization,and galvanic corrosion current tests） were used to investigate the effect of the galvanic corrosion between the bolt/nut couples on the corrosion behaviors of bolts and nuts. The results depict that the highest potential difference and galvanic current are observed between the Cd-plated30CrMnSiA bolts and passivated 0 Cr16 Ni6 nuts,which indicates the most significant galvanic effects. Further,the galvanic corrosionsensitivity rating reaches an E level,which significantly promotes the propagation of the pitting corrosion of the bolt. Additionally,the acceleration factor（AF） becomes 3. 4. For the couple including the Cd-plated 30CrMnSiA bolt and Zn-plated 30CrMnSiA nut,the nut acts as an anode. Further,the corrosion rate of the nut increases,and the AF approximately becomes 1. 2. Compared to the aforementioned two couples,the Cd-plated 30CrMnSiA bolt and 30CrMnSiA nut exhibit the weakest galvanic effect,and the galvanic corrosion sensitivity rating is observed to be at an A level.
作者
朱金阳
李明
李刚
彭兴月
傅耘
ZHU Jin-yang;LI Ming;LI Gang;PENG Xing-yue;FU Yun(AVIC China Aero-Polytechnology Establishment, Beijing 100028, China)
出处
《工程科学学报》
EI
CSCD
北大核心
2018年第2期217-225,共9页
Chinese Journal of Engineering
基金
国防科工局技术基础资助项目(JSJC2013209B058)
关键词
电偶腐蚀
螺栓/螺母
装配
镀镉
镀锌
钝化
galvanic corrosion
bolt/nut
assembling
Cd plating
Zn plating
passivation
