1Cr12Ni3Mo2VN不锈钢的电化学腐蚀行为

Electrochemical Corrosion Behavior of 1Cr12Ni3Mo2VN Stainless Steel

为探究氯离子环境下阳极极化对于马氏体不锈钢的腐蚀行为、再钝化行为的影响,采用循环极化、恒电位极化、电化学阻抗谱等电化学测试方法,并利用激光共聚焦显微镜、扫描电镜、能谱仪和X射线光电子能谱等手段研究阳极极化电位对1Cr12Ni3Mo2VN不锈钢耐蚀性的影响,分析了材料点蚀与再钝化的行为过程,以及耐蚀性与钝化膜成分的关系。结果表明,钝化区低电位下极化时表面不发生点蚀,钝化膜中Cr_(2)O_(3)、Fe_(2)O_(3)含量占比增加而氢氧化物减少,增强了钝化膜的稳定性,材料耐蚀性提高;钝化区高电位下极化时电化学阻抗谱低频区出现感抗弧,材料表面形成稳态点蚀,蚀孔呈半椭球形,蚀孔内表层Cr、Mo含量升高而Fe、Ni含量降低;在混合电位下降至保护电位后发生再钝化现象,修复后的钝化膜较薄,阻抗值减小,点蚀敏感性增加。

To investigate the effects of anodic polarization on the corrosion behavior and re-passivation behavior of martensitic stainless steel in a chloride ion environment,electrochemical testing methods including cyclic polarization,constant potential polarization,and electrochemical impedance spectroscopy(EIS)were employed.Additionally,the influence of anodic polarization potential on the corrosion resistance of 1Cr12Ni3Mo2VN stainless steel was studied using confocal laser scanning microscope(CLSM),scanning electron microscope(SEM),energy dispersive spectrometer(EDS)and X-ray photoelectron spectroscopy(XPS).The study analyzed the behavior processes of pitting and re-pas-sivation of the material,as well as the relationship between corrosion resistance and the composition of the passivation film.Results showed that no pitting corrosion was observed on the surface after polarization at a low potential in the passivation zone.The content of Cr_(2)O_(3)and Fe_(2)O_(3)in the passivation film was found to increase,while the content of hydroxides decreased,which enhanced the stability of the passivation film and improved the material's corrosion resistance.When the passivation area was polarized at a high potential,an inductive arc appeared in the low-frequency region of the electrochemical impedance spectrum,and a stable pitting corrosion was formed on the material's surface.The pitting holes were semi-ellipsoidal,and the content of Cr and Mo in the surface layer of the pitting holes increased,while the content of Fe and Ni de-creased.After the mixed potential dropped to the protection potential,re-passivation occurred.The repaired passivation film was thinner,the impedance value decreased,and the pitting sensitivity increased.