裂解汽油加氢二段反应器急冷剂管道开裂原因分析及对策

CAUSE ANALYSIS AND COUNTERMEASURES FOR CRACKING OF QUENCH PIPELINE IN SECOND-STAGE REACTOR OF PYROLYSIS GASOLINE HYDROGENATION

对裂解汽油加氢二段反应器急冷剂管道因化学腐蚀和应力腐蚀引起的开裂进行了溯源分析。通过对1号外管宏观及低倍金相检验、样管化学成分分析、样管显微组织分析、电镜观察及能谱分析等方式进行综合分析急冷剂管道开裂原因。确定氯离子应力腐蚀开裂起主导作用,焊缝及热影响区敏化加速了开裂进程,采取相应对策有效地防止管道开裂发生,为乙烯裂解汽油加氢装置长周期安全稳定运行提供了保障。

The traceability analysis of the cracking of quench pipeline in second-stage reactor of pyrolysis gasoline hydrogenation caused by chemical corrosion and stress corrosion was carried out.Through the macroscopic and low-magnification metallographic examination of the 1#outer tube,the chemical composition analysis of the sample tube,the microstructure analysis of the sample tube,the electron microscope observation and the energy spectrum analysis,the reasons for the cracking of quench pipeline were comprehensively analyzed.It was determined that chloride ion stress corrosion cracking played a leading role,and the sensitization of welds and heat-affected zone accelerated the cracking process.Corresponding countermeasures were taken to effectively prevent the cracking of pipelines,which provides a guarantee for the long-term,safe and stable operation of pyrolysis gasoline hydrogenation unit.