某合成氨甲烷化装置脱硫槽焊接接头开裂原因  

Reason for Cracking of Welded Joint in Desulfurization Tank of a Synthetic Ammonia Methanation Unit

作　　者：汤鹏杰 梁斌 TANG Pengjie;LIANG Bin(Nanjing Jinchuang Non-ferrous Metal Technology Development Limited Company,Nanjing 211178,China;Nanjing Boiler and Pressure Vessel Inspection Institute,Nanjing 210019,China)

机构地区：[1]南京金创有色金属科技发展有限公司,南京211178 [2]南京市锅炉压力容器检验研究院,南京210019

出　　处：《机械工程材料》2023年第5期66-71,共6页Materials For Mechanical Engineering

基　　金：江苏省应急管理科技项目(YJGL-YF-2020-11);南京市市场监督管理局重点科技项目(Kj2021041)。

摘　　要：某合成氨甲烷化装置中的15Cr Mo R钢脱硫槽在运行10万h后,其焊接接头发生开裂导致泄漏。采用宏观形貌观察、化学成分测试、力学性能试验、显微组织观察和断口分析等方法,对接头开裂原因进行分析。结果表明:氢脆是脱硫槽接头开裂失效的主要原因。相比于母材,焊缝和热影响区强度高,氢脆敏感性强,长期在高温高压临氢环境中服役后,氢原子在脱硫槽内表面焊缝和热影响区聚集,导致氢致开裂。因甲烷化装置中换热器频繁内漏,脱硫槽经历多次紧急停工,造成焊接接头损伤累积,加速裂纹扩展,从而导致脱硫槽开裂泄漏。The welded joint of 15CrMoR steel desulfurization tank in a synthetic ammonia methanation unit was cracked,leading to leakage after operation for 105 h.The reason for cracking of the joint was analyzed by macromorphology observation,chemical composition testing,mechanical property testing,microstructure observation and fracture analysis.The results show that hydrogen embrittlement was the main reason for cracking failure of the desulfurization tank joint.Comparing with the base metal,the weld and heat-affected zone had higher strength and higher hydrogen embrittlement sensitivity.After long-term serving in a high temperature and high pressure hydrogen environment,hydrogen atoms gathered in the weld and heat-affected zone on the inner surface of the desulfurization tank,resulting in hydrogen-induced cracking.Because of frequent internal leakage of the heat exchanger in the methanation device,the desulfurization tank experienced multiple emergency shutdown,resulting in accumulation of damage of the welded joint,which accelerated crack propagation,and led to cracking and leakage of the desulfurization tank.

关 键 词：15CRMOR钢 焊缝 热影响区 氢脆 

分 类 号：TG142.1[一般工业技术—材料科学与工程]