采用化学成分分析，拉伸试验，金相显微镜和扫描电镜等方法对TA2受电弓角断裂原因进行了分析。结果表明：TA2受电弓角的断裂为疲劳断裂，疲劳源位于螺栓孔处弯管的外壁，断口有清晰的贝纹线特征，疲劳扩展区观察到疲劳辉纹；螺栓孔的左侧靠外壁处有明显的挤压变形痕迹，螺栓孔受到高频次的碰撞或外力挤压是TA2受电弓角发生疲劳断裂的主要原因。最后提出了相应的改进措施。

The reasons for fracture of TA2 arch bend were estimated by chemical composition analysis, tensile testing, metalloscopy and scanning electron microscropy (SEM). The results indicate that the fracture of TA2 arch bend was fatigue break, the fatigue source was located at the outer wall of the elbow at bolt hole, the fracture displayed shell strips obviously, the fatigue striations were observed at the fatigue crack propagation zone. Some obvious signs of extrusion deformation were found near the outer wall on the left side of the bolt hole. The main reason for TA2 arch bend fracture was that the bolt hole suffered high frequency collision or external force extrusion. Corresponding improved measures were proposed.