A surface modification film was formed on Fe24Mn4A15Cr alloy in 1 mol/L Na2SO4solution at 620 mV by anodic passivation aging technology. Effect of anodic aging time on stability and pitting corrosion resistance of the anodically passivated layer were studied by using electrochemical impedance spectroscopy ( EIS ) , ZsimpWin software simulation and anodic polarization measurements respectively. The results indicate that the Niquist of passivationalloys after 15 min and 3 h show the radius of one capacitive arc in 1 mol/L Na2SO4 solu tion, and a suitable equivalent circuit R(QR) is chosen through fitting. With increasing the aging time,the di ameters of the capacitive and the passive film capacitance Rp increased. With increasing anodic passivation time from 15 min to 5 h,the Warburg impedance is occurred in EIS,and Rp is increased by 15 kΩ ? Cm2. The anodic polarization curve of the anodically passivated layer shows self passivation in 0. 3 and 0. 5 mol/L Cl- solutions, and the potential of pitting breakdown is increased compared with Fe-24Mn-4Al-5Cr alloy, which indicates that the pitting corrosion resistance is improved greatly.%采用阳极钝化时效技术对Fe24Mn4Al5 Cr合金在1 mol/L Na2SO4溶液中、于620 mV电位下进行“内源”表面改性处理.利用电化学交流阻抗(EIS)测试技术和Zsimp Win软件拟合技术研究钝化时间对钝化膜稳定性的影响规律,并利用阳极极化测试技术研究阳极钝化改性层在NaCl溶液中的抗点蚀性能.研究结果表明:钝化15 min和3h改性层的EIS谱呈现偏移横轴的单容抗弧,电极反应过程的等效电路为R(QR),随钝化时间的增加,容抗弧直径增大,钝化膜电阻Rp增加.钝化5h时,改性层的Nyquist图呈现典型的Warburg阻抗,Rp增加了15 kΩ·cm2.其在不同Cl-浓度(0.3和0.5 mol/L)溶液中的阳极极化曲线均呈现自钝化-点蚀击穿过程,与原始合金相比,维钝电流密度减小,点蚀击穿电位升高,具有较好的抗点蚀性能.
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