通过形貌观察、化学成分分析、硬度测试、显微组织和断口分析等方法，分析了核电站辅助锅炉安全阀弹簧断裂的原因，采用慢应变速率试验（SSRT）比较了去氢前后弹簧的力学性能。结果表明：弹簧的化学成分和显微组织均符合标准规定，仅氢含量略高（2.8 μg/g），弹簧在较高的剪切力作用下发生氢脆断裂是其失效的主要原因；SSRT后，与原始弹簧相比，去氢后弹簧的抗拉强度有所降低，断裂时间延长40%，断后伸长率由8%提高到15%，断面收缩率由21%提高到31%，弹簧的氢脆敏感性明显降低。

The fracture reasons of safety valve spring of auxiliary boiler in a nuclear power station were analyzed by morphology observation, chemical composition analysis, hardness test, microstructure and fracture analysis, and the slow strain rate test (SSRT) was used to compare the mechanical performance of the spring before and after dehydrogenation. The results showed that chemical composition and microstructure of the spring all met standard regulation, only its hydrogen content was slightly high (2.8 μg/g). The fracture was hydrogen embrittlement fracture. The hydrogen embrittlement fracture of spring under high shear force was the main reason for its failure. Compared with the original spring, the tensile strength of the spring after dehydrogenation was reduced after SSRT test, the cracking time increased by 40%, and the elongation increased from 8% to 15%, the reduction of area increased from 21% to 31%. The hydrogen embrittlement sensitivity of spring was significantly reduced.