Cr25Ni35Nb炉管焊缝在高温硫和混合盐环境中的腐蚀行为研究  

Corrosion Behavior of Cr25Ni35Nb Furnace Pipe Weld in High Temperature Sulfur and Mixed Salt Environment

作　　者：胡盼[1,2] 张强 刘春娇[1,2] 陈涛 陈学东[1,2] HU Pan;ZHANG Qiang;LIU Chunjiao;CHEN Tao;CHEN Xuedong(Hefei General Machinery Research Institute,Hefei 230031,China;National Safety Engineering Technology Research Center for Pressure Vessels and Pipelines,Hefei 230031,China)

机构地区：[1]合肥通用机械研究院,安徽合肥230031 [2]国家压力容器与管道安全工程技术研究中心,安徽合肥230031

出　　处：《热加工工艺》2018年第23期21-24,共4页Hot Working Technology

基　　金：国家高技术研究发展计划(863计划)项目(2015AA034402)

摘　　要：为研究裂解加氢尾油时炉管焊缝处的主导腐蚀机理,采用扫描电镜、X射线衍射仪和能谱分析仪分别考察乙烯裂解炉管用Cr25Ni35Nb焊接接头在750℃的单质硫和75%Na2SO4+25%NaCl混合盐模拟环境中的腐蚀行为。结果表明,Cr25Ni35Nb焊接接头焊缝处在单质硫环境中的腐蚀产物分两层,外层为Cr和S元素组成的致密层,内层为Cr、S和Ni等元素组成的疏松层;Cr25Ni35Nb焊接接头焊缝处在混合盐环境中的腐蚀产物分为三层,外层含O、Cr、Si、Na和Cl,中间层为Cr、Ni、O等元素组成的疏松层,内层为致密氧化物层。通过对比某企业裂解加氢尾油时炉管焊缝处与模拟环境中腐蚀产物的形态和元素分布,结果表明裂解加氢尾油时炉管焊缝腐蚀的主导腐蚀机理为硫酸盐的混合盐导致的热腐蚀。For studying the corrosion mechanism of the furnace pipe weld during the cracking of hydrogenation residual oil,the corrosion behaviors of Cr25Ni35Nb welded joint of ethylene cracking furnace pipe in sulfur environment and 75% Na2SO4+25% NaCl mixed salt environment at 750℃ were investigated by scanning electron microscopy,X-ray diffractometer and energy spectrum analyzer.The results show that the corrosion products in sulfur environment consist of two layers,the external layer is relatively compact structure with Cr and S,the internal layer is porous structure with Cr,S and Ni.The corrosion products in mixed salt environment consist of three layers,the external layer contains O,Cr,Si,Na and Cl,the middle layer is porous structure with Cr,Ni,O and the internal layer is a compact oxide layer.By comparing the distribution of elements and morphology of the corrosion products of the furnace weld in a plant hydrogenation residual oil cracking environment with that in the simulated environments,it shows that the corrosion mechanism of the furnace weld in hydrogenation residual oil cracking environment is hot corrosion caused by sulfate mixed salt.

关 键 词：加氢尾油 乙烯裂解炉管 硫化 硫化氧化 热腐蚀 

分 类 号：TG401[金属学及工艺—焊接] TG172.6