压缩机入口管道疲劳断裂分析

Analysis of Fatigue Fracture in Compressor Inlet Pipe

针对某压缩机气体入口管道出现的疲劳断裂问题,对管道材料进行了金相分析和断口分析,开展了疲劳裂纹扩展试验,对管道进行了振动和疲劳裂纹扩展分析。分析结果表明该管道为高周低应力疲劳断裂。入口管道的压力不均匀度超过API 618的限定值。在刚性管卡支撑下,若管道气体入口螺纹根部出现微小裂纹,在压力波动的激振力作用下,其疲劳裂纹扩展寿命为6.8年;若管卡为弹性管卡,疲劳裂纹扩展寿命会显著降低。

Considering gas inlet pipe’s fatigue fracture in a compressor,both metallographic and fracture analysis were made on the pipe materials,including fatigue crack propagation test and pipe vibration analysis.The results show that,the inlet pipe fracture is high cycle and low stress fatigue fracture and its pressure nonuniformity exceeds the limit value of API 618;under the support of rigid pipe clamps,if a tiny crack appeared at the thread root of the gas inlet pipe and the excitation force caused by the pressure fluctuation,the fatigue crack growth life of the pipeline can be 6.8 years and for the elastic pipe clamps,the fatigue crack growth life can be significantly reduced.