芳烃装置热电偶保护套管断裂分析及应对措施

Analysis and Countermeasures of Thermocouple Cannula Fracture in Aromatics Unit

通过对保护套管断裂处的宏观及低倍形貌分析、金相显微组织分析、电镜MES微观形貌分析等手段,对芳烃装置的热电偶套管断裂进行失效分析,确认保护套管断裂性质为双向弯曲疲劳断裂。热电偶保护套管根部为应力集中处,首先产生疲劳裂纹,随着疲劳裂纹不断扩展,最终造成热电偶保护套管断裂失效,并针对此情况给出应对措施。

By analyzing the macro and low magnification morphology,metallographic microstructure analysis,and electron microscopy MES micromorphology analysis of the fracture of the thermocouple cannula,the failure analysis of the fracture of the thermocouple Cannula of the aromatics complex unit was confirmed that bidirectional bending fatigue fracture.The root of the thermocouple cannula is a stress concentration point,and fatigue cracks first occur.As the fatigue cracks continue to expand,eventually the thermocouple cannula breaks and fails,and corresponding countermeasures are given for this situation.