针对某反应堆冷却剂泵电机转子铜条在制造过程中出现的裂纹问题,通过分析和观察金属化学成分、力学性能、断面形貌、显微组织等手段,对其失效原因进行了分析。结果发现,裂纹断面具有沿晶脆性断裂特征,转子铜条在高温挤压过程中产生初始裂纹,初始裂纹在后续的拉制过程中扩展。针对裂纹产生的原因,通过优化参数与加强质量检验改进转子铜条的制造过程,优化后的铜条无明显裂纹缺陷。

Aiming at the problem of cracking in a rotor bar of reactor coolant pump motor during manufacturing, the failure reasons were analyzed by analysis and observation of chemical composition, mechanical properties, fracture morphology and microstructure. It was found that the fracture of rotor bar showed an characteristic of intergranular brittle fracture. The initial crack in rotor bar was generated in the process of high temperature extrusion and expanded in the subsequent drawing process. The manufacture process of rotor bar was improved by optimizing parameters and strengthening quality inspection according to the cause of crack, and the optimized rotor bar had no obvious crack defects.