电连接器压线卡断裂分析

电连接器产品组装交付用户并贮存半年后，发现H62黄铜压线卡发生断裂。通过对压线卡宏观观察、微观观察、能谱分析、硬度检查、金相检查，以及同批次压线卡的人工断口、硬度以及金相组织的对比分析，确定此次电连接器压线卡的断裂模式为应力腐蚀。断裂原因主要有两方面：一是压线卡内热缩膜体积较大导致压线卡承受较大拉应力；二是压线卡镀层表面发生破坏失去了保护基体材料的作用，在这两个方面因素的综合作用下最终导致压线卡发生应力腐蚀断裂。建议进一步对压线卡内热缩膜的体积进行量化控制，同时对电连接器压线卡表面镀层的生产、贮存、使用等过程进行控制，避免对镀层的损伤破坏。

Failure Analysis of Pressure Line Card in Electric Connector

A pressure line card of H62 brass in the electric connector was found to have fractured after storage for six months. In the present work, the failure mode and cause of the pressure line card were analyzed by micro and macro observation, EDS analysis, hardness test and metallurgical structure examination. And the artificial fracture surface, hardness, metallurgical structure of a good pressure line card of the same batch were analyzed for comparison with the failed one. The results show the failure mode is stress corrosion. There were two causes for the failure that one was high tensile stress led by the high volume of heat crinkle membrane in the pressure line card; another was that the damage of the surface plating resulted in the loss of its protection function. The volume of the heat crinkle membrane should be controlled, and the surface plating should be protected during production, storage and service.