采用宏观检验、化学成分分析、力学性能试验、金相检验、断口宏微观分析等方法，对某台1 000 MW核电汽轮机径向可倾瓦轴承空心螺栓的断裂原因进行了分析。结果表明：螺栓的失效类型为过载断裂；螺栓质量不合格是导致其断裂的主要原因，一方面螺栓内螺纹退刀槽尺寸不符合标准要求，使螺栓承载面积显著减小，另一方面螺栓强度及硬度偏低，也降低了螺栓的承载能力。

The fracture causes of a hollow bolt used on the radial tilting bearing of a 1 000 MW nuclear power turbine were analyzed by macro examination, chemical composition analysis, mechanical property test, metallographic examination and macroscopic and microscopic fracture analysis. The results show that the failure type of the bolt was overload fracture. The unqualified bolt quality was the main reason for its fracture. On the one hand, the size of the cutter groove of inner thread of the bolt didn't meet the standard requirements, which significantly reduced the bearing area of the bolt. On the other hand, the strength and hardness of the bolt were rather low, which also reduced the bearing capacity of the bolt.