Abstract: The corrosion behaviors of cold rolled sheet, galvanized sheet, aluminum sheet and their electrophoretic crevices in the neutral salt fog environment were studied, their macroscopic corrosion morphology was analyzed, and the corrosion morphology and composition were characterized by scanning electron microscope, energy disperse spectroscopy and other microscopic analysis methods. The results show that in the same corrosion environment, the crevices of the above universal metal materials are more prone to corrosion, especially the crevices of the cold rolled plate are the most serious, which produce a large amount of Fe3O4 and Fe2O3, showing poor corrosion resistance. The oxygen content of the crevice corrosive surface of galvanized sheet is higher, and more Fe2O3 is produced, while the oxygen content of the crevice corrosive surface of aluminum plate is the lowest, and a small amount of Al2O3 is produced, showing good corrosion resistance. The corrosion resistance of the crevice of the electrophoretic material was improved obviously. Finally, according to the technical requirements of automobile structure and the corrosion status of the above-mentioned metal crevices, the recommended conclusions for selecting crevice materials in automobile body, engine compartment, chassis and other areas are given.

Key words: Automobile metal material crevice; Corrosion behavior; Neutral salt fog environment

摘要： 文章研究了冷轧板、镀锌板、铝板及其在电泳后的汽车车身通用金属材料缝隙在中性 盐雾环境中的腐蚀行为，并分析了宏观腐蚀形貌，采用扫描电子显微镜、能谱仪等微观分析 手段表征了腐蚀形貌和成分。结果表明，在同一腐蚀环境中，上述通用金属材料缝隙处更容 易产生腐蚀，尤其冷轧板缝隙腐蚀程度最严重，产生了大量的 Fe3O4 和 Fe2O3，呈现出较差的 耐蚀性；镀锌板缝隙腐蚀面的氧含量较高，产生了较多的 Fe2O3；铝板缝隙表面的氧含量最低， 产生了少量的 Al2O3，呈现出较好的耐蚀性；电泳后的材料缝隙处的耐蚀性得到了明显的改善。 最后，根据汽车结构工艺要求及上述金属缝隙处的腐蚀状况，得出汽车车身、发动机舱、底 盘等区域选择缝隙搭载材料的推荐性结论。

关键词: 汽车金属材料缝隙；腐蚀行为；中性盐雾环境