Water vapour effects of cyclic oxidation on Fe-Cr alloys

Fe-Cr alloys (Cr: 9-30 wt%) were subjected to cyclic oxidation in Ar-20%O2, Ar-20%O2-5%H2O and Ar-10%H2-5%H2O (partial pressure of oxygen, pO2 = 1.1 ¥ 10-16atm). Oxidation weight change measurement showed that in general, increasing Cr content reduced the oxidation rate. At Cr < 17%Cr, breakaway...

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Main Authors:	N.K. Othman, N.Othman, J. Zhang, D.J. Young
Format:	Article
Language:	English
Published:	Universiti Kebangsaan Malaysia 2010
Online Access:	http://journalarticle.ukm.my/7327/ http://journalarticle.ukm.my/7327/ http://journalarticle.ukm.my/7327/1/01_Md_Yeaminhossain.pdf

id	ukm-7327
recordtype	eprints
spelling	ukm-73272016-12-14T06:43:45Z http://journalarticle.ukm.my/7327/ Water vapour effects of cyclic oxidation on Fe-Cr alloys N.K. Othman, N.Othman, J. Zhang, D.J. Young, Fe-Cr alloys (Cr: 9-30 wt%) were subjected to cyclic oxidation in Ar-20%O2, Ar-20%O2-5%H2O and Ar-10%H2-5%H2O (partial pressure of oxygen, pO2 = 1.1 ¥ 10-16atm). Oxidation weight change measurement showed that in general, increasing Cr content reduced the oxidation rate. At Cr < 17%Cr, breakaway oxidation was observed. However, for Cr > 25%, the weight gain became very low due to formation of Cr2O3 layer. Adding 5%H2O to Ar-20%O2 accelerated the oxidation rate of alloys with Cr < 20%. However, this accelerating effect did not appear in high chromium content alloys. XRD analysis showed that for alloys with Cr < 20%, wustite and spinel were formed at low pO2, while at high pO2, hematite, iron oxide and spinel were formed. For high Cr content alloy only Cr2O3 was detected. Cross-section analysis showed that the spinel was formed by internal oxidation. The thickness and size of this internal oxide zone increased with increasing Cr content. A dense chromia layer was observed when the Cr content was above 25%. The oxides scales formed in water vapour were more porous and less compact than the scale formed in dry oxygen. The accelerating effect of water vapour on Fe-Cr oxidation is discussed in terms of gas-solid interactions. Universiti Kebangsaan Malaysia 2010-04 Article PeerReviewed application/pdf en http://journalarticle.ukm.my/7327/1/01_Md_Yeaminhossain.pdf N.K. Othman, and N.Othman, and J. Zhang, and D.J. Young, (2010) Water vapour effects of cyclic oxidation on Fe-Cr alloys. Sains Malaysiana, 39 (2). pp. 249-259. ISSN 0126-6039 http://www.ukm.my/jsm/english_journals/vol39num2_2010/contentsVol39num2_2010.html
repository_type	Digital Repository
institution_category	Local University
institution	Universiti Kebangasaan Malaysia
building	UKM Institutional Repository
collection	Online Access
language	English
description	Fe-Cr alloys (Cr: 9-30 wt%) were subjected to cyclic oxidation in Ar-20%O2, Ar-20%O2-5%H2O and Ar-10%H2-5%H2O (partial pressure of oxygen, pO2 = 1.1 ¥ 10-16atm). Oxidation weight change measurement showed that in general, increasing Cr content reduced the oxidation rate. At Cr < 17%Cr, breakaway oxidation was observed. However, for Cr > 25%, the weight gain became very low due to formation of Cr2O3 layer. Adding 5%H2O to Ar-20%O2 accelerated the oxidation rate of alloys with Cr < 20%. However, this accelerating effect did not appear in high chromium content alloys. XRD analysis showed that for alloys with Cr < 20%, wustite and spinel were formed at low pO2, while at high pO2, hematite, iron oxide and spinel were formed. For high Cr content alloy only Cr2O3 was detected. Cross-section analysis showed that the spinel was formed by internal oxidation. The thickness and size of this internal oxide zone increased with increasing Cr content. A dense chromia layer was observed when the Cr content was above 25%. The oxides scales formed in water vapour were more porous and less compact than the scale formed in dry oxygen. The accelerating effect of water vapour on Fe-Cr oxidation is discussed in terms of gas-solid interactions.
format	Article
author	N.K. Othman, N.Othman, J. Zhang, D.J. Young,
spellingShingle	N.K. Othman, N.Othman, J. Zhang, D.J. Young, Water vapour effects of cyclic oxidation on Fe-Cr alloys
author_facet	N.K. Othman, N.Othman, J. Zhang, D.J. Young,
author_sort	N.K. Othman,
title	Water vapour effects of cyclic oxidation on Fe-Cr alloys
title_short	Water vapour effects of cyclic oxidation on Fe-Cr alloys
title_full	Water vapour effects of cyclic oxidation on Fe-Cr alloys
title_fullStr	Water vapour effects of cyclic oxidation on Fe-Cr alloys
title_full_unstemmed	Water vapour effects of cyclic oxidation on Fe-Cr alloys
title_sort	water vapour effects of cyclic oxidation on fe-cr alloys
publisher	Universiti Kebangsaan Malaysia
publishDate	2010
url	http://journalarticle.ukm.my/7327/ http://journalarticle.ukm.my/7327/ http://journalarticle.ukm.my/7327/1/01_Md_Yeaminhossain.pdf
first_indexed	2023-09-18T19:49:23Z
last_indexed	2023-09-18T19:49:23Z
_version_	1777406116541497344

Water vapour effects of cyclic oxidation on Fe-Cr alloys

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