汽油滤清器泄漏原因分析

LEAK ANALYSIS OF THE GASOLINE FILTER

汽油滤清器在整车进行24个循环试验后发生泄漏。利用宏观分析、金相检验和扫描电镜及能谱分析等手段对汽油滤清器泄漏原因进行了分析。结果表明,缝隙腐蚀和电偶腐蚀是造成汽油滤清器罐体早期泄漏的主要原因。汽油滤清器罐体与支架在最初阶段由于接触区域存在缝隙,发生了缝隙腐蚀,致使汽油滤清器罐体铝发生点蚀、支架镀层局部脱落;镀层脱落后,滤清器罐体铝与支架基体由于电极电位的不同进而发生了电偶腐蚀,加速了滤清器罐体腐蚀的进程,导致汽油滤清器发生泄漏。

Gasoline filter was found leak after 24 whole vehicle cycles test. Leak reason was analyzed by macro-examination, microstructure examination, SEM and energy spectrum analysis, and the results showed that crevice corrosion and galvanic corrosion were the main reason for the leak. Crevice corrosion took place in early stage between the crevice of the filter＇s tank and bracket, which resulted in pitting of the filter＇s tank and falling of the zinc coating of the filter＇s bracket. Then galvanic corrosion happened because of the different electrode voltage of the bracket basal body and the tank, which speed up the corrosion of the tank and led to the leak of fuel filter only after 24 cycles test.