某石化公司氢气压缩机缸盖螺栓发生断裂, 采用宏、微观断口分析、化学成分分析、金相检验以及力学性能测试等试验手段分析了该氢气压缩机缸盖螺栓的断裂原因。结果表明: 断裂起源于螺杆与螺栓头部连接螺纹末端的应力集中处, 由于应力集中, 加之螺栓强度等级偏低, 使螺栓在长期工作过程中的往复交变应力和扭转应力共同作用下发生了低应力高周疲劳断裂。

Fracture of hydrogen compressor cylinder head bolts happened in a petrochemical company, and the fracture reasons were analyzed by means of macro and micro fracture analysis, chemical compositions analysis, microstructure examination, and tensile and impact test. The results indicate that the fracture originated at the threaded end of connection of the screw head and bolt where the stress was concentration. Because the stress concentration, coupled with the low grade of bolt strength, the low stress high cycle fatigue fracture occurred for the cylinder head bolts under the long term coaction of reciprocating alternating stress and torsion stress.