Pitting corrosion of 304 stainless steel in secondary water supply system

Corrosion Communications Pub Date : 2022-09-01 DOI:10.1016/j.corcom.2021.11.010

Kuijiao Li , Li Sun , Wenkai Cao , Si Chen , Zhiwei Chen , Yanli Wang , Weihua Li

{"title":"Pitting corrosion of 304 stainless steel in secondary water supply system","authors":"Kuijiao Li , Li Sun , Wenkai Cao , Si Chen , Zhiwei Chen , Yanli Wang , Weihua Li","doi":"10.1016/j.corcom.2021.11.010","DOIUrl":null,"url":null,"abstract":"<div>The effect of NaClO solution on pitting behavior of 304 stainless steel was investigated by electrochemical tests and composition analysis. The results show that the open circuit potential (OCP) shifts to the positive direction with the increase of [ClO−], indicating that the passivation film formed on the sample surface is faster, but, has no effect on pitting potential (Eb) in the first stage (< 24 h). After 24 h immersion, the pitting occurs because Cl− is detected in the wake of the decomposition of ClO− for its thermodynamics instability. In the later stage, the [Cl−] increases with the increase of [ClO−], correspondingly resulting in lower pitting resistance. X-ray photoelectron spectroscopy (XPS) reveals that the Cr/Fe atomic ratio in the passivation film decreases with the increase of [ClO−], because Cr(III) is oxidized to Cr(VI) and dissolves in the solution, which further weakens the pitting resistance of 304 stainless steel. The electrochemical impedance spectroscopy (EIS), combined with the Mott-Schottky analysis (MSA) was employed to verify the properties of the passivation film related to pitting.</div>","PeriodicalId":100337,"journal":{"name":"Corrosion Communications","volume":"7 ","pages":"Pages 43-50"},"PeriodicalIF":0.0000,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2667266922000457/pdfft?md5=acbc9bdcc3dcc6e444419bc510c41b99&pid=1-s2.0-S2667266922000457-main.pdf","citationCount":"5","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Corrosion Communications","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2667266922000457","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}

引用次数: 5

Abstract

The effect of NaClO solution on pitting behavior of 304 stainless steel was investigated by electrochemical tests and composition analysis. The results show that the open circuit potential (OCP) shifts to the positive direction with the increase of [ClO⁻], indicating that the passivation film formed on the sample surface is faster, but, has no effect on pitting potential (E_b) in the first stage (< 24 h). After 24 h immersion, the pitting occurs because Cl⁻ is detected in the wake of the decomposition of ClO⁻ for its thermodynamics instability. In the later stage, the [Cl⁻] increases with the increase of [ClO⁻], correspondingly resulting in lower pitting resistance. X-ray photoelectron spectroscopy (XPS) reveals that the Cr/Fe atomic ratio in the passivation film decreases with the increase of [ClO⁻], because Cr(III) is oxidized to Cr(VI) and dissolves in the solution, which further weakens the pitting resistance of 304 stainless steel. The electrochemical impedance spectroscopy (EIS), combined with the Mott-Schottky analysis (MSA) was employed to verify the properties of the passivation film related to pitting.

查看原文本刊更多论文

二次供水系统304不锈钢的点蚀

通过电化学试验和成分分析，研究了nacl溶液对304不锈钢点蚀行为的影响。结果表明:随着[ClO−]浓度的增加，开路电位(OCP)向正方向移动，表明在样品表面形成钝化膜的速度加快，但对第一阶段的点蚀电位(Eb) (<24 h后，由于ClO -的热力学不稳定性，在ClO -分解后检测到Cl -，从而发生点蚀。在后期，[Cl−]随着[ClO−]的增加而增加，相应地导致点蚀电阻降低。x射线光电子能谱(XPS)显示，钝化膜中Cr/Fe原子比随着[ClO−]浓度的增加而降低，这是由于Cr(III)被氧化为Cr(VI)并溶解于溶液中，进一步削弱了304不锈钢的抗点蚀性。采用电化学阻抗谱(EIS)结合Mott-Schottky分析(MSA)验证了钝化膜与点蚀相关的性能。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Corrosion Communications

CiteScore

7.30

自引率

0.00%

发文量