Criteria for the formation of protective Al2O3 scales on Fe-Al and Fe-Cr-Al alloys

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	Criteria for the formation of protective Al2O3 scales on Fe-Al and Fe-Cr-Al alloys
	Z. G. Zhang; F. Gesmundo; P. Y. Hou; Y. Niu
	2006
发表期刊	Corrosion Science
ISSN	0010-938X
卷号	48 期号:3 页码:741-765
摘要	The conditions for the formation of external alumina scales on binary Fe-Al alloys and the nature of the third-element effect due to chromium additions have been investigated by studying the oxidation at 1000 degrees C in 1 atm O-2 of a binary Fe-10 at.% Al alloy (Fe-10Al) and of two ternary Fe-Cr-10 at.% Al alloys containing 5 and 10 at.% chromium (Fe-5Cr-10Al and Fe-10Cr-10Al, respectively). An Al-rich scale developed initially on Fe-10Al was subsequently replaced by a multi-layered scale containing mixtures of Fe and Al oxides plus a large number of Fe-rich oxide nodules: internal aluminum oxidation was essentially absent from this alloy. Addition of 5 at.% chromium to Fe-10Al did not suppress the formation or nodules, but they were eventually healed by the growth of all alumina layer at their base, resulting in a significant reduction of the oxidation rate. Finally, the alloy with 10 at.% Cr formed continuous external alumina scales without any Fe-rich nodule. Thus, the addition of sufficient amounts of chromium to Fe-10Al produces a third-element effect as expected. However, the process found in this alloy system does not involve a prevention of the internal oxidation of Al. Instead, it shows a transition from the growth of mixed Fe- and Al-rich external scales directly to all external Al2O3 scale formation. An interpretation of this kind of mechanism involving a third-element is presented along with a prediction of the critical Al contents required to produce the various possible scaling modes on binary Fe-Al alloys. (C) 2005 Elsevier Ltd. All rights reserved.
部门归属	chinese acad sci, inst met res, state key lab corros & protect, shenyang 110016, peoples r china. univ genoa, dichep, i-16129 genoa, italy. lawrence berkeley natl lab, div mat sci, berkeley, ca 94720 usa.;niu, y (reprint author), chinese acad sci, inst met res, state key lab corros & protect, wencui rd 62, shenyang 110016, peoples r china;yniu@imr.ac.cn
关键词	Fecral Ternary Alloys Oxidation Cr Effect Iron-aluminum-alloys High-temperature Oxidation High Oxidant Pressures y Alloys Internal Oxidation Growth Mechanisms External Oxidation Self-diffusion Base Alloys Gamma-iron
URL	查看原文
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/34731
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	Z. G. Zhang,F. Gesmundo,P. Y. Hou,et al. Criteria for the formation of protective Al2O3 scales on Fe-Al and Fe-Cr-Al alloys[J]. Corrosion Science,2006,48(3):741-765.
APA	Z. G. Zhang,F. Gesmundo,P. Y. Hou,&Y. Niu.(2006).Criteria for the formation of protective Al2O3 scales on Fe-Al and Fe-Cr-Al alloys.Corrosion Science,48(3),741-765.
MLA	Z. G. Zhang,et al."Criteria for the formation of protective Al2O3 scales on Fe-Al and Fe-Cr-Al alloys".Corrosion Science 48.3(2006):741-765.