制氢转化炉猪尾管开裂失效分析与解决措施  

Failure Analysis and Solutions of Cracking in Down-Tail Tube of Hydrogen Manufacturing Conversion Furnace

作　　者：姜瑞文 周一斌 JIANG Ruiwen;ZHOU Yibin(SINOPEC Engineering Department,Beijing 100728,China;SINOPEC Fujian Refining&Chemical Company,Quanzhou 362000,China)

机构地区：[1]中国石油化工集团有限公司工程部,北京100728 [2]中国石化福建炼化公司,福建泉州362000

出　　处：《石油化工腐蚀与防护》2020年第1期48-54,共7页Corrosion & Protection In Petrochemical Industry

摘　　要：福建某石化企业40×10^3 m^3/h制氢转化炉停用期间,TP347H材质的猪尾管发生普遍性断裂。结合转化炉结构、运行及修复情况,采用铁磁相含量测定、拉伸、腐蚀和硬度试验、化学成分和金相组织分析、断口形貌观察及能谱分析等手段,分析了裂纹产生及开裂的原因,结果表明:原材料产生了敏化;猪尾管在正常操作条件下高温强度等性能满足使用要求且近2年的间歇运行表明材料的持久塑性良好;高温条件下材质发生劣化使其弯管和焊接凸台部位的抗拉强度和延伸率降低,伴有金属原始组织和性能变化;内应力使材料产生蠕变及应力松弛,且在应力和穿晶型Cl^-腐蚀环境下产生晶间腐蚀裂纹;停工状态下管系的温度梯度和重力产生的变形差超出了恒力吊挂补偿范围而失稳;猪尾管受力变形量超出了其弹塑性变形补偿范围,使凸台和弯管内侧应力集中敏感部位首先开裂。根据失效原因,提出了转化炉修复的解决方案,制定了防护措施,确保装置安全、平稳和长周期运行,也为制氢工艺同类问题处理提供借鉴。Fractures occurred in TP347 H down-tail tube during shutdown of 40×10^3 m^3/h hydrogen manufacturing conversion furnace in an enterprise in Fujian. Combined with structure, operation and maintenance of the furnace, causes were studied by a series of tests, analyses and observations. It was shown that the raw materials were sensitized;material of down-tail tube had good durable plasticity under normal operation, however, its performance was deteriorated under high temperature, which generated intergranular corrosion crack under stress and transgranular Cl^- corrosion environment;piping system lost stability due to deformation difference of temperature gradient and gravity under shutdown, stress deformation of down-tail tube exceeded compensation range of elastoplastic deformation, so that sensitive part of boss and bend inside cracked first. Solutions and protective measures were proposed which provide reference for avoiding similar problems in hydrogen production process.

关 键 词：制氢转化炉 猪尾管 应力腐蚀 

分 类 号：TQ116.2[化学工程—无机化工] TQ054