催化裂化装置膨胀节失效原因与措施

针对大连石化公司催化裂化装置膨胀节的失效，利用电子能谱(EDX)、SEM电镜扫描等手段对失效膨胀节进行检测分析，得出膨胀节失效的主要原因是膨胀节的工作温度正处于其敏化温度，膨胀节在各种残余应力和硫酸、连多硫酸等特定腐蚀介质共同作用下发生的应力腐蚀开裂导致的失效，并首次提出采用填料函结构来补偿冷热变形的解决方案，使用效果极好. 

FAILURE ANALYSIS OF EXPANSION JOINT IN FCC AND REMEDIAL MEASURE

In order to understand the history of failures of expansion joints made of stainless steel 316L in fluid catalytic cracking(FCC) of Dalian Petrochemical Corporation,an analysis was performed by means of various techniques including EDX and SEM examinations.The results showed that the temperature of expansion joints was in the range of sensitizing temperature of steel 316L, the magnitude of residual stress in expansion joint and special corrosive media are main factors of failure of the expansion joints. At last, according to operating conditions,a sovereign remedy is to replace expansion joint by a packed slip joint. It is proved that the packed slip joint can act not only as proper compensator for thermal expansion, but also avoid SCC. This remedial measure may be recommended to apply to other FCC.