氰酸钠熔盐中金属材料的高温侵蚀行为研究  

High temperature erosion behavior and microstructure of metallic materials in molten salt of sodium cyanate

作　　者：谢天赋 甘章华[1] 邱鹏云 吴传栋 刘意 王佳敏 XIE Tianfu;GAN Zhanghua;QIU Pengyun;WU Chuandong;LIU Yi;WANG Jiamin(State Key Laboratory of Refractory Materials and Metallurgy(Wuhan University of Science and Technology),Wuhan 430081,China;Hunan Lide Technology New Material Co.,Ltd.,Hunan 410399,China)

机构地区：[1]省部共建耐火材料与冶金国家重点实验室(武汉科技大学),武汉430081 [2]湖南立德科技新材料有限公司,长沙410399

出　　处：《材料科学与工艺》2024年第6期19-25,共7页Materials Science and Technology

基　　金：国家自然科学基金资助项目(51904213);湖北省重大专项项目(2022BEC025).

摘　　要：氰酸钠熔盐高温反应釜通常采用316L不锈钢制备,高温服役环境的侵蚀失效导致其使用寿命不足。为了提高氰酸钠熔盐反应釜的寿命,本文研究了316L、C-2000、C-276、高纯Ni和高纯Cu五种金属材料在氰酸钠熔盐中的耐侵蚀性。采用差量法测试侵蚀速率,利用体视显微镜和扫描电镜观察了5种样品侵蚀前后的宏观和微观形貌,用XRD和EDS分析侵蚀产物的物相和成分。研究表明:侵蚀速率由小到大依次为Ni_(2)O_(2.4)、CrO_(3)相组成;C-2000表面化合物层和扩散层均由CrN相构成;C-276表面化合物层有CrN和NiO相产生,扩散层以NiO相形式存在。分析认为,氰酸钠高温熔盐对金属的主要侵蚀机理是氮化和氧化。采用高纯铜或高纯镍代替316L不锈钢制备氰酸钠熔盐用反应釜有望提高其使用寿命。The high-temperature reaction kettle for sodium cyanide molten salt is usually made of 316L stainless steel,but its lifespan is insufficient due to high-temperature corrosion failure.In order to improve the lifespan of the sodium cyanide molten salt reactor,this article studied the corrosion resistance of five metal materials,namely 316L,C-2000,C-276,high-purity Ni,and high-purity Cu,in sodium cyanide molten salt.The erosion rate was measured using the differential method,and the macroscopic and microscopic morphology before and after erosion were observed using a stereomicroscope and SEM.The phases and compositions of the erosion products were analyzed using XRD and EDS.The research show that the erosion rates,from lowest to highest,are Ni_(2)O_(2.4),and CrO_(3)phases.The surface compound layer and diffusion layer of C-2000 are both composed of CrN phase.The surface compound layer of C-276 contains CrN and NiO phases,while the diffusion layer exists in the form of NiO phase.The analysis shows that the main erosion mechanisms of sodium cyanate high-temperature molten salt on metals are nitridation and oxidation.The use of high-purity copper or high-purity nickel instead of 316L stainless steel for the preparation of sodium cyanide molten salt in reaction reactors is expected to improve its lifespan.

关 键 词：氰酸钠 侵蚀速率 侵蚀产物 侵蚀机理 反应釜寿命 

分 类 号：TG17[金属学及工艺—金属表面处理]