超临界机组闭式循环冷却泵轴断裂分析及处置建议

Fracture analysis and treatment measures for shaft of closed pump of supercritical unit

某电厂600 MW超临界火电机组的闭式循环冷却泵轴从叶轮位置断裂,自由端滚动轴承损坏。通过对断轴的宏观形貌、微观、化学成分和力学性能等多方面进行分析,发现此轴的断裂可能与疲劳失效和不当的热处理工艺有关,同时提出有针对性的预防措施。

The shaft of closed pump of a 600 MW supercritical thermal power generating unit was fractured from the impeller position,and the free end of the rolling bearing was damaged.Through the analysis of the macro morphology,micro structure,chemical composition and mechanical properties of the broken shaft,it is found that the fracture of the shaft may be related to the fatigue failure and improper heat treatment process.At the same time,the corresponding preventive measures are proposed.