制氢装置转化炉上集合管焊缝开裂分析及措施

某炼油厂20万m^3/h（标准工况）制氢装置转化炉347H材质的上集合管三通与支管连接焊接接头,在使用5个月内相继发生3次开裂。对焊缝裂纹进行失效分析后认为,内壁应力腐蚀开裂是导致泄漏的主要原因,提出了相应对策以及对集合管结构及制造的改进措施。

Failure Analyses and Countermeasure of Gas Gathering Tube of Reformer in Hydrogen Unit

The welding connection between tee pipe and branch pipe of 347H upper gas gathering tube in the refinery 20×104 m3/h（standard operation） hydrogen unit reformer have ruptured succession 3 times during service for 5 months.It is confirmed that stress corrosion cracking initiation from internal wall is a main reason leading to leakage by analysis failure about crackled welding.The closedown during baking stove made steam prone to condensing,existing tendency of corrosion product assembling.The weld position has aloft work and spot stabilizing treatment were difficult to guarantee quality,therefore these reduce stress corrosion resistance and promote cracking process.The relevant operating measurements,gas gathering tube structure and manufacture improvement measures were proposed.