Fe30Mn5Al合金氧化改性层的电化学腐蚀性能  

Electrochemical Corrosion Behavior of Oxidation Layer on Fe30Mn5Al Alloy

作　　者：朱雪梅[1] 张振卫 王新建[1] 张彦生[1] 

机构地区：[1]大连交通大学材料科学与工程学院,辽宁大连116028

出　　处：《材料工程》2017年第8期83-87,共5页Journal of Materials Engineering

基　　金：国家自然科学基金资助项目(59901003)

摘　　要：将Fe30Mn5Al合金在800℃空气中循环氧化160h,在氧化层与基体之间获得厚度约为15μm的贫Mn,富Fe铁素体层,研究氧化改性贫Mn层对Fe30Mn5Al合金电化学腐蚀性能的影响。结果表明:在1mol·L-1 Na2SO4溶液中,与原始合金相比,贫Mn层的阳极极化曲线呈自钝化,自腐蚀电位Evs SCE从-750mV提高至-130mV,钝化电流密度ip从310μA/cm2下降至29μA/cm2;电化学交流阻抗谱(EIS)的容抗弧直径及|Z|值增加,相位角平台变宽,利用等效电路Rs-(Rt//CPE)拟合的极化电阻Rt由2.7kΩ·cm2增至9.9kΩ·cm2;贫Mn层比合金基体具有更好的抗蚀性能。The Fe30Mn5Al alloy was oxidized at 800℃ in air for 160h, the oxidation-induced layer a-bout 15jLtm thick near the scale-metal interface was induced to transform to ferrite and become enriched in Fe and depletion in Mn. The effect of the oxidation-induced Mn depletion layer on the electrochemi-cal corrosion behavior of Fe30Mn5A1 alloy was evaluated. The results show that in lmol · L-1 Na2S04 solution, the anodic polarization curve of the Mn depletion layer exhibits self-passivation, compared with Fe30Mn5Al austenitic alloy, and the corrosion potential Eu Sce is inc rea sed to - 1 3 0m V from -750mV and the passive current density zp is decreased to 29μA/cm2from 310μA/cm2. The elec-trochemical impedance spectroscopy（EIS） of the Mn depletion layer has the larger diameter of capaci-tive arc, the higher impedance modulus ｜Z｜ , and the wider phase degree range, and the fitted polari-zation resistant Rt is increased to 9. 9kΩ · cm2 f rom 2. 7kΩ ·cm2 by using an equivalent elect r ic ci rcui t of Rs-（Rt/ /CPE）. The high insulation of the Mn depletion layer leads to an improved corrosion resist-ance of Fe30Mn5Al austenitic alloy.

关 键 词：Fe30Mn5Al合金 氧化改性层 阳极极化 电化学交流阻抗 

分 类 号：TG174.422[金属学及工艺—金属表面处理]