接触线中心锚结线夹断裂分析及改进

FRACTURE ANALYSIS AND IMPROVEMENT OF CONTACT WIRE MID-ANCHOR CLAMP

QSi13接触线中心锚结线夹在服役一年多后断裂。采用光学显微镜、扫描电子显微镜、化学成分分析等方法对线夹的失效原因进行了分析。结果表明,使用时紧固力矩过大、关键尺寸偏小是断裂主要原因,而工艺过程有过热导致晶粒粗大加速了线夹的失效。提出了取消原工艺中的刨齿工序,改为精密模锻成型并加强热处理工序质量控制的改进措施。

Crack of QSi1-3 contact wire mid-anchor clamp was discovered after working over a year. By means of the metallo-graphical examination, SEM, chemical composition analysis etc, the failure cause of clamp was analyzed. Finding out that fastening torque too big and key dimension too small on running are main reason of cracking, and technology process is over hot that it makes big grain crystal partially accelerates the clamp failure. Many improvement measures were adopted as follows: using precision die and forging model instead of dig process of original technology, and strength quality controlled of heat treatment process.