Effect of hot working characteristics on the texture development in AISI 430 and 433 ferritic stainless steel

dc.contributor.advisorStumpf, Waldo E.en
dc.contributor.advisorSiyasiya, Charles Witnessen
dc.contributor.emailahomkaannan@yahoo.comen
dc.contributor.postgraduateAnnan, Kofi Ahomkah
dc.date.accessioned2013-09-06T21:19:33Z
dc.date.available2013-06-12en
dc.date.available2013-09-06T21:19:33Z
dc.date.created2013-04-04en
dc.date.issued2012en
dc.date.submitted2013-06-10en
dc.descriptionDissertation (MSc)--University of Pretoria, 2012.en
dc.description.abstractThe last seven hot rolling passes of the ferritic stainless steels (FSS) AISI 430 and AISI 433 (the latter an Al-added variant of 430) were simulated on Gleeble-1500D® and Gleeble-3800TM® thermo-mechanical simulators to investigate the effect of temperature, strain rate and inter-pass time on the development of texture in these steel grades and its subsequent influence on ridging. The compression tests were carried out over a wide range of strain rates (0.1 s-1 to 5 s-1, 25 s-1 and 50 s-1) and temperatures (1100 to 820 oC) with different inter-pass times (2 s, 10 s, 20 s and 30 s). The transition temperature from dynamic recrystallization (which may introduce a texture change) to dynamic recovery (in which no texture changes are expected) was determined by examining the relationship between the mean flow stress and the deformation temperature in multi-pass tests. Both macrotexture (XRD) and microtexture (EBSD) analyses were employed to characterise and study the texture present in these steels. It was found that the texture in the central layer of the compressed sample is a strong recrystallization-type. The through-thickness textural and microstructural banding was found to be responsible for ridging in these grades of stainless steels. Dynamic recrystallization which promotes the formation of the desired ã-fibre texture leading to high ductility, formability and eventually reduction or elimination of ridging, was found to occur in both AISI 430 and AISI 433 at high temperatures, low strain rates and longer inter-pass times with multi-pass testing. Generally AISI 433 has a stronger gamma texture developed than the AISI 430 when hot rolled under similar conditions, which leads to improved ductility and less ridging in AISI 433 than AISI 430.en
dc.description.availabilityunrestricteden
dc.description.departmentMaterials Science and Metallurgical Engineeringen
dc.identifier.citationAnnan, KA 2012, Effect of hot working characteristics on the texture development in AISI 430 and 433 ferritic stainless steel, MSc dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://hdl.handle.net/2263/25436 >en
dc.identifier.otherE13/4/729/gmen
dc.identifier.upetdurlhttp://upetd.up.ac.za/thesis/available/etd-06102013-170011/en
dc.identifier.urihttp://hdl.handle.net/2263/25436
dc.language.isoen
dc.publisherUniversity of Pretoriaen_ZA
dc.rights© 2012 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoriaen
dc.subjectDynamic recrystallizationen
dc.subjectElectron backscattering diffractionen
dc.subjectDynamic recoveryen
dc.subjectFerritic stainless steels (fss)en
dc.subjectEbsden
dc.subjectHot rollingen
dc.subjectUCTDen_US
dc.titleEffect of hot working characteristics on the texture development in AISI 430 and 433 ferritic stainless steelen
dc.typeDissertationen

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