通过断口形貌观察、X射线能谱分析、金相检验和硬度检测等试验方法, 对某燃油供油导管快卸卡箍螺栓的断裂原因进行了分析, 并与螺栓冲击断口和氢致疲劳断口进行了比较分析。结果表明: 该快卸卡箍螺栓断口特征与冲击断口和氢致疲劳断口明显不同, 其断裂性质为应力腐蚀断裂, 裂纹起源于螺栓光杆段的侧表面; 螺栓表面加工粗糙且没有防护对裂纹的萌生有一定的影响。对螺栓表面进行防腐处理可有效避免该类故障的再次发生。

In order to investigate the fracture reason of a quick-release clamp bolt, means such as fracture observation, X-ray energy spectrum analysis, microstructure and hardness examinations were carried out, and the fracture of failed bolt was contrasted with the impacted fracture and hydrogen-embrittlement induced fatigue fracture. The results show that the bolt was fractured due to stress corrosion, and the crack firstly started from the outer surface of the bolt rod. Rough machining and no protection of the bolt surface contributed to the cracks initiation. The anti-corrosive treatment should be adopted to prevent happening the similar failure again.