Fe-Cr合金在650℃共晶(Li,K)_2CO_3熔盐中的腐蚀电化学阻抗谱研究  

CORROSION ELECTROCHEMICAL-IMPEDANCE OF Fe-Cr ALLOYS IN EUTECTIC (Li,K)_2CO_3 MIXTURE AT 650℃

作　　者：曾潮流[1] 王文[1] 吴维 

机构地区：[1]中国科学院金属腐蚀与防护研究所金属腐蚀与防护国家重点实验室,沈阳110015

出　　处：《腐蚀科学与防护技术》2000年第5期249-253,共5页Corrosion Science and Protection Technology

基　　金：国家自然科学基金

摘　　要：应用电化学阻抗技术并结合物相分析技术研究了合金元素Cr对Fe在 650℃ (Li,K) 2 CO3 共晶熔盐中的腐蚀行为的影响 .结果表明 ,加入 5 %和 1 0 %Cr不能改善Fe的耐腐蚀性能 ,而加入 2 0 %和 2 5 %Cr则能显著提高其耐腐蚀性能 ;Fe及Fe Cr合金腐蚀电化学阻抗谱呈双容抗弧特征 ,合金腐蚀受荷电粒子在氧化膜中的迁移控制 .提出将合金表面形成的氧化膜理想化为一电容器 ,并建立了氧化物电容与双电层电容相串联的等效电路来描述合金腐蚀的阻抗特征 .此外 ,根据所提等效电路对合金腐蚀电化学阻抗谱进行了解析 .Electrochemical impedance as well as physical analysis techniques were employed to study the effect of Cr on the corrosion of pure iron in eutectic (Li,K) 2CO 3 mixture at 650℃. The results indicated that the addition of 5% and 10%Cr to pure iron had little effect on its corrosion resistance, however the additives of 20% and 25%Cr could greatly improve the corrosion resistance of iron. The Nyquist plots for the corrosion of pure Fe and Fe\|Cr alloys in the melt were composed of two capacitance loops, and the corrosion was controlled by the transportation of species in the scale. It was proposed that the oxide scale be idealized as a capacitor, thus, an equivalent circuit of oxide capacitance in series with double\|layer capacitance was established to represent the impedance spectra for Fe and Fe\|Cr alloys. Additionally, based on the equivalent circuit proposed, the impedance spectra were evaluated.

关 键 词：燃料电池 FE-CR合金 熔盐腐蚀 电化学阻抗 

分 类 号：TM911.4[电气工程—电力电子与电力传动] TG172.62[金属学及工艺—金属表面处理]