pH值对马氏体沉淀硬化不锈钢PH13-8Mo腐蚀电化学行为的影响  

Effect of pH Value of Na_2SO_4 Solutions on Electrochemical Corrosion Behavior of PH13-8Mo Precipitation Hardening Stainless Steel

作　　者：李雪莹[1] 范春华[1] 吴钱林[1] 钟宁[1] 董丽华[1] 尹衍升 

机构地区：[1]上海海事大学海洋科学与工程学院,上海201306

出　　处：《腐蚀科学与防护技术》2017年第4期349-355,共7页Corrosion Science and Protection Technology

基　　金：国家重点基础研究发展计划(2014CB643306)~~

摘　　要：通过静态浸泡腐蚀实验以及极化曲线测试、电化学阻抗谱测试、Mott-Schottky曲线等电化学测试技术,结合扫描电子显微镜技术研究了马氏体沉淀硬化不锈钢PH13-8Mo在不同pH值的0.5 mol/L的Na_2SO_4溶液中的腐蚀行为。结果表明:PH13-8Mo的耐蚀性随着溶液pH值的升高而增强,不同的pH值影响了腐蚀的速率及腐蚀产物的形貌。随着溶液pH值的升高,腐蚀电流密度Icorr减小,极化电阻Rp增大,容抗弧的幅值增大,钝化膜中缺陷密度降低,钝化膜的致密性增强,耐腐蚀性能提高。The electrochemical corrosion behavior of martensite precipitation hardening stainless steel PH13-8Mo in 0.5 mol/L Na_2SO_4 solutions with different pH value was investigated by means of static immersion corrosion test, polarization curve measurement, electrochemical impedance spectroscopy,Mott-Schottky curve measurement and scanning electron microscopy. The results show that, with the increasing pH value the corrosion resistance of the PH13-8Mo is enhanced, while the corrosion rate and the morphology of the corrosion products change; the corrosion current density Icorrdecreases, the polarization resistance RPand capacitive arc amplitude increases, and the density of defects in the passive film lowers. In other word, with the increasing pH value the corrosion resistance of the steel is enhanced in the 0.5 mol/L Na_2SO_4 solution.

关 键 词：极化曲线 电化学阻抗谱 Mott-Schottky曲线 钝化膜 PH值 

分 类 号：TG174[金属学及工艺—金属表面处理]