Identification of MnCr(2)O(4) nano-octahedron in catalysing pitting corrosion of austenitic stainless steels

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	Identification of MnCr(2)O(4) nano-octahedron in catalysing pitting corrosion of austenitic stainless steels
	S. J. Zheng; Y. J. Wang; B. Zhang; Y. L. Zhu; C. Liu; P. Hu; X. L. Ma
	2010
发表期刊	Acta Materialia
ISSN	1359-6454
卷号	58 期号:15 页码:5070-5085
摘要	Pitting corrosion of stainless steels, one of the classical problems in materials science and electrochemistry, is generally believed to originate from the local dissolution in MnS inclusions, which are more or less ubiquitous in stainless steels. However, the initial location where MnS dissolution preferentially occurs is known to be unpredictable, which makes pitting corrosion a major concern. In this work we show, at an atomic scale, the initial site where MnS starts to dissolve in the presence of salt water. Using in situ ex-environment transmission electron microscopy (TEM), we found a number of nano-sized octahedral MnCr(2)O(4) crystals (with a spinel structure and a space group of Fd (3) over barm) embedded in the MnS medium, generating local MnCr(2)O(4)/MnS nano-galvanic cells. The TEM experiments combined with first-principles calculations clarified that the nano-octahedron, enclosed by eight {1 1 1} facets with metal terminations, is "malignant", and this acts as the reactive site and catalyses the dissolution of MnS. This work not only uncovers the origin of MnS dissolution in stainless steels, but also presents an atomic-scale evolution in a material's failure which may occur in a wide range of engineering alloys and biomedical instruments serving in wet environments. (C) 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
部门归属	[zheng, s. j.; wang, y. j.; zhang, b.; zhu, y. l.; liu, c.; ma, x. l.] chinese acad sci, inst met res, shenyang natl lab mat sci, shenyang 110016, peoples r china. [hu, p.] queens univ belfast, sch chem & chem engn, belfast bt9 5ag, antrim, north ireland.;ma, xl (reprint author), chinese acad sci, inst met res, shenyang natl lab mat sci, shenyang 110016, peoples r china;xlma@imr.ac.cn
关键词	Scanning/transmission Electron Microscopy (Stem) Corrosion Catalysis Electrochemistry Stainless Steel Sulfide Inclusions Mns Inclusions Pit Initiation Oxidation Dissolution Microscopy Mechanism Stress Metals Alloys
URL	查看原文
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/31760
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	S. J. Zheng,Y. J. Wang,B. Zhang,et al. Identification of MnCr(2)O(4) nano-octahedron in catalysing pitting corrosion of austenitic stainless steels[J]. Acta Materialia,2010,58(15):5070-5085.
APA	S. J. Zheng.,Y. J. Wang.,B. Zhang.,Y. L. Zhu.,C. Liu.,...&X. L. Ma.(2010).Identification of MnCr(2)O(4) nano-octahedron in catalysing pitting corrosion of austenitic stainless steels.Acta Materialia,58(15),5070-5085.
MLA	S. J. Zheng,et al."Identification of MnCr(2)O(4) nano-octahedron in catalysing pitting corrosion of austenitic stainless steels".Acta Materialia 58.15(2010):5070-5085.