宋乐平，周毅，朱涛

（同济大学 汽车学院，上海 201804）

摘要：针对某汽油发动机机油冷却器的泄漏失效进行研究。通过X射线裂纹扫描技术以及SEM（扫描电子显微镜）分析等方法，发现机油冷却器的泄漏原因为生产过程中局部区域过量的助焊剂与冷却液发生水解反应，导致在该区域无法形成冷却液防腐保护膜，并伴随产生了白色絮状产物，由于该腐蚀区域存在电化学腐蚀，加剧水解反应过程，最终导致机油冷却器泄漏。

关键词：机油冷却器；助焊剂；泄漏；腐蚀；冷却液

Abstract：This paper focuses on the internal leakage failure of a gasoline engine oil cooler. By X-Ray crack scan and SEM analysis technology, it was found that the reason for the internal leakage of the oil cooler was hydrolysis reaction between excess flux remained from welding process and coolant. The hydrolysis reaction leading to the anticorrosive protective film not be able to form in the area. As a result, white gels was created with hydrolysis reaction ongoing. Because of the electrochemical corrosion in the region, the process of hydrolysis reaction was increased, which resulted in the leakage of oil cooler.

Key Words：oil cooler; flux; leakage; corrosion; coolant