基于海洋大气环境因素影响下的碳钢腐蚀特征研究  

Corrosion Characteristics of Carbon Steel in Simulated Marine Atmospheres

作　　者：万晔[1] 宋芳龄 李立军 WAN Ye;SONG Fangling;LI Lijun(School of Materials Science and Engineering,Shenyang Jianzhu University,Shenyang 110168,China)

机构地区：[1]沈阳建筑大学材料科学与工程学院,沈阳110168

出　　处：《中国腐蚀与防护学报》2022年第5期851-855,共5页Journal of Chinese Society For Corrosion and Protection

基　　金：辽宁省“兴辽英才计划”项目(XLYC2002005);辽宁省教育厅项目(lnjc202016及lnqn202019)

摘　　要：研究了碳钢在模拟海洋大气环境中的腐蚀特征,探讨了紫外线及Cl^(-)对碳钢腐蚀行为的影响。采用双束聚焦离子束系统考察了碳钢点蚀孔洞中点蚀产物三维形貌特征,利用X射线透射仪检测点蚀产物的立体构造。结果表明,在薄液膜环境中,在紫外光线辐照条件下碳钢表面发生钝化,在海洋大气环境中碳钢因Cl^(-)的侵蚀作用,表面发生明显的点蚀现象。点蚀发展后长大为三维核壳结构的花样点蚀产物,点蚀花的核心Cl^(-)浓度高、氧含量极低,而点蚀花壳上的Cl^(-)浓度低、氧含量较高。点蚀底部Cl^(-)浓度最高,具有自催化效应腐蚀机制。Marine atmospheric parameters,such as UV light irradiation,temperature,relative humidity,and chloride ions,may affect the corrosion behavior of metallic materials.The effects of the UV lights irradiation and chloride ions on pitting corrosion behaviors of carbon steel were investigated in a simulated marine atmospheres.The 3D images of the pitting were revealed via a combination of dual-beam focused ion beam system with scanning electron microscope(FIB/SEM)system,while the 3D stereoscopic vision was examined by using an X-ray micro-tomography.The results show that UV light irradiation could induce passivation of the carbon steel beneath a thin liquid film,and thus a thin oxide film might form on the carbon steel surface.Pitting corrosion occurred due to the aggressive chloride ions piercing through the oxide film on the surface of carbon steel.Three dimensional(3D)images demonstrated that the flowers-like pitting corrosion products with core-shell structure were formed as the pitting developed.The elemental distributions in the pitting areas exhibited high content of chloride and low content of oxygen in the core,while low content of chloride and high content of oxygen in the shell.The content of chloride ions was the highest in the bottoms of the pits,which then resulted in a pitting mechanism related with autocatalytic reaction.

关 键 词：碳钢 点蚀 海洋大气 Cl^(-) 

分 类 号：TG174[金属学及工艺—金属表面处理]