块体纳米晶Fe-50Cu合金在H2SO4溶液中的电化学腐蚀行为  

Electrochemical Corrosion Behavior of Nanocrystalline Fe-50Cu Bulk Alloys in H2SO4 Solutions

作　　者：崔田路 曹中秋[1] 贾中秋 于佳蕊 徐欢[1] 张轲[1] 王艳[1] CUI Tianlu;CAO Zhongqiu;JIA Zhongqiu;YU Jiarui;XU Huan;ZHANG Ke;WANG Yan(College of Chemistry and Chemical Engineering,Shenyang Normal University,Shenyang 110034,China)

机构地区：[1]沈阳师范大学化学与化工学院,沈阳110034

出　　处：《材料导报》2020年第20期20096-20102,共7页Materials Reports

基　　金：国家自然科学基金(51271127,51501118);辽宁省重点研发计划项目(2018304025);辽宁省教育厅科研项目(LJC201911)。

摘　　要：采用电化学方法,通过测试开路电位、极化曲线和交流阻抗谱等研究了粉末冶金法(PM)制备的一种常规尺寸以及液相还原法(LPR)和机械合金化法(MA)热压制备的两种纳米晶块体Fe-50Cu合金在不同浓度H 2SO 4溶液中的电化学腐蚀行为及显微组织对其腐蚀性能的影响。结果表明:三种不同方法制备的Fe-50Cu合金的腐蚀电流密度均随着H 2SO 4溶液浓度的增加而增大,腐蚀速度变快。三种Fe-50Cu合金的交流阻抗谱均由单容抗弧组成,表明腐蚀过程受电化学反应控制,它们的传递电阻随着H 2SO 4溶液浓度的增加而减小。在相同浓度的H 2SO 4溶液中,晶粒细化后,合金的腐蚀电流密度增加,合金耐蚀性能下降。纳米晶LPR Fe-50Cu合金的腐蚀电流密度比纳米晶MA Fe-50Cu合金大,传递电阻和活化能比纳米晶MA Fe-50Cu合金小。因此,其腐蚀速率比纳米晶MA Fe-50Cu合金快。The electrochemical corrosion properties and effect of microstructures on them of a coarse grained and two nanocrystalline Fe-50Cu bulk alloys prepared by powders metallurgy(PM)as well as the liquid phase reduction(LPR)and mechanical alloying(MA)methods with hot pressing,respectively,were investigated in H 2SO 4 solutions by means of electrochemical methods through measuring open circuit potentials,potentiodynamic polarization,electrochemical impedance spectroscopies,and so on.The results show that the corrosion current densities of three Fe-50Cu alloys prepared by the different methods increase with the increment of H 2SO 4 solution concentrations.Their electrochemical impedance spectroscopies are composed of a single capacitive arc,indicating the corrosion processes are controlled by the electrochemical reactions.The changed trend of charge transfer resistances of three Fe-50Cu alloys is adverse to that of corrosion current densities.In the same H 2SO 4 solution concentrations,the corrosion current densities increase and therefore corrosion properties decrease when the grain sizes are decreased.The corrosion current densities of LPR Fe-50Cu alloy are larger,the activation energies and charge trnasfer resistances are lower and therefore its corrosion rates are faster than those of nanocrystalline MA Fe-50Cu alloy.

关 键 词：腐蚀电化学 纳米晶 Fe-Cu合金 显微组织 机械合金化 液相还原 

分 类 号：TG113.23[金属学及工艺—物理冶金]