汽车发动机油冷器管板钎焊接头失效分析

Fracture failure analysis on tube-sheet joints of automotive engine oil cooler

文中对汽车发动机油冷器产品的泄漏失效件进行了剖析,结果显示:油冷器产品失效位置位于紫铜散热管一镀铜低碳钢法兰管板钎焊焊缝;通过扫描电镜分析(SEM)及能谱分析(EDS)发现管板钎焊接头低碳钢/钎缝界面存在连续的脆性磷铁化合物,焊缝沿此界面发生了脆性开裂。文中还从工作介质的压力脉冲、发动机振动、冲击等载荷分析了产品的受力状态及其对钎焊焊缝的影响。在此基础上,提出了相应的改进措施。为产品的质量改进提供有益参考。

The failed tube-sheet brazed joints of automobile engine oil cooler were analyzed.The results show that the cracks appear along the copper plated low-carbon steel/copper brazed seam.Continuous brittle Ferro phosphorus compounds were found on the interface near the low carbon steel side in the brazed joint by SEM and EDS,which leads to the crack eventually.The effect of working loads such as pressure pulse, vibration and impact loads on the tube-sheet joints were also analyzed.In addition,the corresponding measures were proposed to improve the quality of the product.