纳米孪晶强化CoCrFeNi高熵合金线材微结构及其在若干典型环境下的腐蚀行为  

Microstructure and Corrosion Behavior in Several Typical Conditions of Nano-Twinned CoCrFeNi High-Entropy Alloy Wires

作　　者：周晖 霍文燚 方峰[1] 胡显军 蒋建清[1,3] Zhou Hui;Huo Wenyi;Fang Feng;Hu Xianjun;Jiang Jianqing(Jiangsu Key Laboratory of Advanced Metallic Materials,Southeast University,Nanjing 211189,China;Institute of Research of Iron and Steel of Jiangsu Province/Sha-Steel,Zhangjiagang 215625,China;Nanjing Forestry University,Nanjing 210037,China)

机构地区：[1]东南大学江苏省先进金属材料高技术研究重点实验室,江苏南京211189 [2]江苏省沙钢钢铁研究院,江苏张家港215625 [3]南京林业大学,江苏南京210037

出　　处：《稀有金属》2018年第12期1233-1240,共8页Chinese Journal of Rare Metals

基　　金：国家自然科学基金面上项目(51371050);江苏省重点研发项目(BE2015097);江苏省产学研前瞻基金项目(BY2016076-08);江苏省六大人才高峰项目(2015-XCL-004);张家港市重点研发项目(ZKG1614);东南大学研究生院科研基金项目(YBJJ1726)资助

摘　　要：纳米孪晶强化CoCrFeNi高熵合金线材以其优异的力学性能被视为是传统线材面向苛刻工况应用的潜在替代品。采用电弧熔炼、冷热机械加工、剧烈冷变形技术制备纳米孪晶强化CoCrFeNi高熵合金线材,采用场发射扫描电镜(FE-SEM)、透射电镜(TEM)分析其微结构,利用电化学分析在3. 5%(质量分数) Na Cl,1 mol·L^(-1)H2SO4,1 mol·L^(-1)Na OH溶液中分别分析CoCrFeNi高熵合金线材的腐蚀行为,采用FESEM观察其在不同介质中的腐蚀形貌,分析CoCrFeNi高熵合金线材在不同介质中的腐蚀机制。结果表明,CoCrFeNi高熵合金线材经冷变形后呈纤维状组织,其在3种典型环境下的耐蚀性均较为理想。其在3. 5%Na Cl溶液中的腐蚀机制主要为点蚀,自腐蚀电流密度低至3. 85×10^-7A·cm^(-2),腐蚀后仅有极少量蚀坑存在。而在1 mol·L^(-1)H2SO4与1 mol·L^(-1)Na OH溶液为均匀腐蚀,自腐蚀电流密度分别可达1. 26×10^-6,7. 88×10^-6A·cm^(-2),腐蚀形貌呈均匀腐蚀特征。CoCrFeNi高熵合金线材在3. 5%Na Cl溶液、1 mol·L^(-1)H2SO4溶液与1 mol·L^(-1)Na OH溶液中均具有较好的耐蚀性,具备在这几种典型环境应用的潜力。Nano-twinned CoCrFeNi high-entropy alloy wires could replace conventional wires in applications for harsh conditions,owing to their excellent mechanical properties.They were prepared by arc melting,cold-and hot-machining,heavy cold deformation.The microstructure was analyzed by field-emission scanning electron microscope (FE-SEM)and transmission electron microscope (TEM). The corrosion behaviors of high-entropy alloy wires were examined in 3.5%(mass fraction)NaCl solution,1mol·L-1 H2SO4solution and 1mol·L^-1NaOH solution.And the corrosion surfaces were analyzed by FE-SEM.The results showed that the corrosion resistance of high-entropy alloy wires in these typical conditions was ideal,and its corrosion mechanism in 3.5%NaCl solution was pitting.The corrosion current density was 3.85×10^-7A·cm-2.And the mechanism in 1mol·L-l H2SO4solution and 1mol·L^-1NaOH solution were uniform corrosion.The corrosion current density was 1.26×10^-6and 7.88×10^-6A·cm-2,respectively.The wires had great potential for applications,due to their outstanding corrosion resistance in these conditions.

关 键 词：高熵合金 纳米孪晶 形变 电化学行为 腐蚀机制 

分 类 号：TG172[金属学及工艺—金属表面处理]