电解质对Fe23Mn5Cr合金钝化膜的结构及耐蚀性能影响

Effects of Electrolyte on Structure and Corrosion Resistance of Passive Film Formed on Fe23Mn5Cr Alloy

运用电化学阳极钝化技术对Fe23Mn5Cr合金分别于50%HNO3溶液及1.0mol/LNa2SO4溶液中进行表面钝化时效5h处理;利用X射线光电子能谱(XPS)表面分析技术及电位衰减曲线和阳极极化曲线测试技术研究电解质对Fe23Mn5Cr合金钝化时效改性膜的组成结构与耐蚀性能的影响.结果表明:Fe23Mn5Cr合金在1mol/LNa2SO4溶液中钝化5h所得钝化膜主要由Fe2O3、FeO及MnO组成,在50%HNO3溶液中钝化5h所得钝化膜主要由Cr2O3和Fe2O3组成.与1.0mol/LNa2SO4溶液中的钝化时效改性膜相比,50%HNO3溶液中钝化时效改性膜的Cr2p3/2峰强度增强,Mn2p3/2峰强度减弱,Mn氧化物溶解,具有保护性的Cr氧化物富集,耐蚀性能显著提高,其电位衰减时间由586s延长至8782s,阳极极化曲线呈现自钝化.

The electrochemical anodic aging was used to modify Fe23Mn5Cr alloy in 50%HNO3 solution and 1.0 mol/L Na 2SO 4 solution for 5 h.The constitution and corrosion resistance of passive film formed on the Fe23Mn5Cr alloy were investigated by using X-ray photoelectron spectroscopy,potential decline curve and anodic polarization cures.The results indicate that the passive film formed on the Fe23Mn5Cr alloy in 1.0 mol/L Na2SO4 solution is consisted of Fe2O3,FeO and MnO.The passive film formed in 50%HNO3 solution was consisted of Cr2O3 and Fe2O3.Compared with the passive film formed in 1.0 mol/L Na2SO4 solution,the relative intensity of the Cr2p3/2 passive film formed in 50%HNO3 solution is increased,and the relative intensity of the Mn2p3/2 is decreased.Anodic aging in 50%HNO3 solution oxidiationbrings depletion of the Mn oxide and enrichment of the Cr oxide,which leds to an improved corrosion resistance of the Fe23Mn5Cr alloy.The potential decline time of the modified Fe23Mn5Cr alloy is prolonged from 586 s to 8 782 s,and the anodic polarization cures are changed into self-passivation.