CeO_2改性的渗铬涂层及氧化性能研究  

MICROSTRUCTURAL CHARACTERIZATION AND OXIDATION PERFORMANCE OF A NOVEL CeO_2-MODIFIED CHROMIZING COATING

作　　者：朱利敏[1] 彭晓[1] 

机构地区：[1]中国科学院金属研究所金属腐蚀与防护国家重点实验室

出　　处：《腐蚀科学与防护技术》2005年第2期63-68,共6页Corrosion Science and Protection Technology

基　　金：中科院"引进海外杰出人才"(百人计划 )项目资助

摘　　要：采用在低碳钢上复合电镀Ni- CeO2 后 112 0℃扩散渗铬 4小时的方法 ,制备了CeO2 改性的渗铬涂层 ,涂层的主体由CeO2 弥散分布的外层和不含CeO2 的内层组成 .作为对比 ,用相同工艺在低碳钢及单镍镀层上直接渗铬 ,获得 2种不含CeO2 的渗铬涂层 ;84 0℃下 12 0小时的循环氧化实验表明 ,CeO2 改性的渗铬涂层与不含CeO2 的比较 ,抗氧化性能明显提高 .光学显微镜 (OM)、X光衍射 (XRD)、扫描电镜与能谱 (SEM/EDAX)及电子探针 (EPMA)分析结果表明 ,CeO2 改性的渗铬涂层抗氧化性能的提高 ,在于渗铬涂层中弥散的CeO2 颗粒参与了Cr2 O3 的生长过程 .文中对CeO2 影响渗铬涂层的显微组织及氧化的作用机制进行了探讨 .A novel CeO_2-modified chromizing coating has been developed on a mild carbon steel by a process with two steps:the first one is composite electrodeposition of Ni and CeO_2 particles,followed by the second one of chromizing on the Ni-CeO_2 composite using pack cementation method at 1120℃ for 4 hours.The coating is composed of a major portion of an outer layer with CeO_2 dispersion and a minor portion of an inner layer without CeO_2.For comparison,chromizing was also performed with the same condition on low carbon steel without and with pre-electroplated Ni film but without CeO_2 addition.Cyclic oxidation at 840℃ for 120 h showed that the CeO_2-modified chromizing coating has a superior oxidation resistance to the other two CeO_2-free coatings.Samples before and after oxidation were investigated using OM、XRD、SEM/EDAX and EPMA,the results indicated that the chromia scale formed on CeO_2-dispersed coating was thinner and finer-grained.The effect of CeO_2 on the microstructure and the oxidation of the chromizing coating is discussed in this work.

关 键 词：渗铬 涂层 CEO2 低碳钢 循环氧化 显微组织 EDAX 改性 复合电镀 镍镀层 

分 类 号：TQ153[化学工程—电化学工业] TG156[金属学及工艺—热处理]