H2SO4浓度对00Cr19Mo2NbTi铁素体不锈钢钝化膜的影响  

Effect of H2SO4 concentration on the passive film on 00Cr19Mo2NbTi ferrite stainless steel

作　　者：梁琳 黄艳茹[1] LIANG Lin;HUANG Yanru(College of Sciences,Liaoning Shihua University,Fushun 113001,China)

机构地区：[1]辽宁石油化工大学理学院,辽宁抚顺113001

出　　处：《沈阳师范大学学报（自然科学版）》2020年第2期140-146,共7页Journal of Shenyang Normal University:Natural Science Edition

基　　金：国家自然科学基金青年科学基金项目(1140040740);辽宁省教育厅科学研究经费项目(L2019029)。

摘　　要：采用场发射电子扫描显微镜(SEM)、能量色散X射线光谱(EDS)和电化学测试技术,并结合点缺陷模型(PDM)研究了H2SO4浓度对00Cr19Mo2NbTi铁素体不锈钢钝化膜耐腐蚀性能的影响。SEM和EDS分析表明,钝化膜随着H2SO4浓度增大逐渐增厚、致密,主要成分为Fe和Cr的氧化物。电化学结果显示,交流阻抗谱呈现单容抗弧,容抗弧半径随H2SO4浓度增大而变大。当H2SO4浓度由40%增加至85%时,动电位极化曲线的腐蚀电位正移,腐蚀电流减小。与40%H2SO4钝化试样相比,85%H2SO4钝化试样的腐蚀电位升高了114mV,腐蚀电流下降了2个数量级,电荷转移电阻增大近3倍;在-0.6~0.5V电位区间,钝化膜表现为p-n型半导体特性,85%H2SO4钝化膜的施主浓度最小(1.250×10^22cm^-3),说明氧空位和阳离子间隙减少,钝化膜相对稳定。The effects of H2SO4 concentration on the passive film on 00Cr19Mo2NbTi ferrite stainless steel were studied by means of field emission scanning electron microscope(FESEM),energy dispersive spectroscopy(EDS)and electrochemical measurements,which was combined with the point defect model(PDM).SEM and EDS analysis showed that the passive film on steel became denser and thicker with increasing H2SO4 concentration and the passive film was mainly composed of iron and chromium oxides.The results based on electrochemical measurements revealed that all the feature of nyquist plots was the single capacitive loop,and moreover,the higher the H2SO4 concentration was,the larger the arc radius was.When the H2SO4 concentration was increased from 40%to 85%,the corrosion potential moved positively and the corrosion current decreased.Compared with the passive film in 40% H2SO4 solution,the corrosion potential of passive film in 85% H2SO4 solution increased 114 mV,the corrosion current deduced two orders magnitude and correspondently,the charge transfer resistance increased about three times.The passive film represented a p-n semi-conductor characteristic in the potential interval of-0.6~0.5 V.It was found that the donor density of passive film in 85% H2SO4 solution was minimum(1.250×10^22 cm^-3),which indicated that the oxygen vacancies and cationic interstitials were reduced,as a result,the passive film was more stable compared with the other.

关 键 词：H2SO4 铁素体不锈钢 钝化膜 半导体特性 

分 类 号：TG174.4[金属学及工艺—金属表面处理]