Decomposition of expanded austenite in AISI 316L stainless steel nitrided at 723K
Autor(a) principal: | |
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Data de Publicação: | 2012 |
Outros Autores: | , , |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Institucional da UNESP |
Texto Completo: | http://dx.doi.org/10.1179/1749514812Z.00000000025 http://hdl.handle.net/11449/226975 |
Resumo: | Expanded austenite (γN), which can be produced during plasma nitriding of austenitic stainless steels, provides high levels of strength, toughness and corrosion resistance by comparison with traditional nitride layers. However, expanded austenite properties can be lost due to decomposition caused its thermodynamic metastability. In the present work, austenitic stainless AISI 316L steel was plasma nitrided at 723 K for 5 h at 500 Pa and microstructurally characterised by X-ray diffraction (XRD), and optical and transmission electron microscopy (TEM) which confirmed the presence of fcc expanded austenite with a lattice parameter up to 9·5% larger than untreated austenite. TEM analyses of thin foils showed that fine nitrides were formed in the γN layer and some areas were observed with a singular lamellar morphology very similar to the pearlite colonies found in carbon steels. Selected area electron diffraction (SAED) analysis suggests that these areas are composed of bcc ferrite and cubic chromium nitrides produced after a localised decomposition of the expanded austenite layer. Amorphous expanded austenite was observed in some areas of the investigated samples. The occurrence of γN decomposition was associated with microsegregation of ferrite stabilisers (Cr, Mo) and depletion of an austenite stabiliser (Ni) in localised regions of the expanded austenite layer. © 2012 IHTSE Partnership. |
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Decomposition of expanded austenite in AISI 316L stainless steel nitrided at 723KAmorphous regionsAustenitic stainless steelDecompositionEDS microanalysisExpanded austeniteNitride formationPlasma nitridingTransmission electron microscopyExpanded austenite (γN), which can be produced during plasma nitriding of austenitic stainless steels, provides high levels of strength, toughness and corrosion resistance by comparison with traditional nitride layers. However, expanded austenite properties can be lost due to decomposition caused its thermodynamic metastability. In the present work, austenitic stainless AISI 316L steel was plasma nitrided at 723 K for 5 h at 500 Pa and microstructurally characterised by X-ray diffraction (XRD), and optical and transmission electron microscopy (TEM) which confirmed the presence of fcc expanded austenite with a lattice parameter up to 9·5% larger than untreated austenite. TEM analyses of thin foils showed that fine nitrides were formed in the γN layer and some areas were observed with a singular lamellar morphology very similar to the pearlite colonies found in carbon steels. Selected area electron diffraction (SAED) analysis suggests that these areas are composed of bcc ferrite and cubic chromium nitrides produced after a localised decomposition of the expanded austenite layer. Amorphous expanded austenite was observed in some areas of the investigated samples. The occurrence of γN decomposition was associated with microsegregation of ferrite stabilisers (Cr, Mo) and depletion of an austenite stabiliser (Ni) in localised regions of the expanded austenite layer. © 2012 IHTSE Partnership.Department of Materials Engineering São Carlos School of Engineering University of São Paulo, São Paulo, SPDepartment of Mechanical and Materials Engineering Portland State University, Portland, ORDepartment of Mechanical Engineering Univ Estadual Paulista- UNESP at IIha Solteira, IIha Solteira, SPDepartment of Mechanical Engineering Univ Estadual Paulista- UNESP at IIha Solteira, IIha Solteira, SPUniversidade de São Paulo (USP)Portland State UniversityUniversidade Estadual Paulista (UNESP)Fernandes, F. A.P.Casteletti, L. C.Totten, G. E.Gallego, J. [UNESP]2022-04-29T04:59:18Z2022-04-29T04:59:18Z2012-09-01info:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/article103-106http://dx.doi.org/10.1179/1749514812Z.00000000025International Heat Treatment and Surface Engineering, v. 6, n. 3, p. 103-106, 2012.1749-51481749-5156http://hdl.handle.net/11449/22697510.1179/1749514812Z.000000000252-s2.0-84866692673Scopusreponame:Repositório Institucional da UNESPinstname:Universidade Estadual Paulista (UNESP)instacron:UNESPengInternational Heat Treatment and Surface Engineeringinfo:eu-repo/semantics/openAccess2022-04-29T04:59:18Zoai:repositorio.unesp.br:11449/226975Repositório InstitucionalPUBhttp://repositorio.unesp.br/oai/requestopendoar:29462022-04-29T04:59:18Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP)false |
dc.title.none.fl_str_mv |
Decomposition of expanded austenite in AISI 316L stainless steel nitrided at 723K |
title |
Decomposition of expanded austenite in AISI 316L stainless steel nitrided at 723K |
spellingShingle |
Decomposition of expanded austenite in AISI 316L stainless steel nitrided at 723K Fernandes, F. A.P. Amorphous regions Austenitic stainless steel Decomposition EDS microanalysis Expanded austenite Nitride formation Plasma nitriding Transmission electron microscopy |
title_short |
Decomposition of expanded austenite in AISI 316L stainless steel nitrided at 723K |
title_full |
Decomposition of expanded austenite in AISI 316L stainless steel nitrided at 723K |
title_fullStr |
Decomposition of expanded austenite in AISI 316L stainless steel nitrided at 723K |
title_full_unstemmed |
Decomposition of expanded austenite in AISI 316L stainless steel nitrided at 723K |
title_sort |
Decomposition of expanded austenite in AISI 316L stainless steel nitrided at 723K |
author |
Fernandes, F. A.P. |
author_facet |
Fernandes, F. A.P. Casteletti, L. C. Totten, G. E. Gallego, J. [UNESP] |
author_role |
author |
author2 |
Casteletti, L. C. Totten, G. E. Gallego, J. [UNESP] |
author2_role |
author author author |
dc.contributor.none.fl_str_mv |
Universidade de São Paulo (USP) Portland State University Universidade Estadual Paulista (UNESP) |
dc.contributor.author.fl_str_mv |
Fernandes, F. A.P. Casteletti, L. C. Totten, G. E. Gallego, J. [UNESP] |
dc.subject.por.fl_str_mv |
Amorphous regions Austenitic stainless steel Decomposition EDS microanalysis Expanded austenite Nitride formation Plasma nitriding Transmission electron microscopy |
topic |
Amorphous regions Austenitic stainless steel Decomposition EDS microanalysis Expanded austenite Nitride formation Plasma nitriding Transmission electron microscopy |
description |
Expanded austenite (γN), which can be produced during plasma nitriding of austenitic stainless steels, provides high levels of strength, toughness and corrosion resistance by comparison with traditional nitride layers. However, expanded austenite properties can be lost due to decomposition caused its thermodynamic metastability. In the present work, austenitic stainless AISI 316L steel was plasma nitrided at 723 K for 5 h at 500 Pa and microstructurally characterised by X-ray diffraction (XRD), and optical and transmission electron microscopy (TEM) which confirmed the presence of fcc expanded austenite with a lattice parameter up to 9·5% larger than untreated austenite. TEM analyses of thin foils showed that fine nitrides were formed in the γN layer and some areas were observed with a singular lamellar morphology very similar to the pearlite colonies found in carbon steels. Selected area electron diffraction (SAED) analysis suggests that these areas are composed of bcc ferrite and cubic chromium nitrides produced after a localised decomposition of the expanded austenite layer. Amorphous expanded austenite was observed in some areas of the investigated samples. The occurrence of γN decomposition was associated with microsegregation of ferrite stabilisers (Cr, Mo) and depletion of an austenite stabiliser (Ni) in localised regions of the expanded austenite layer. © 2012 IHTSE Partnership. |
publishDate |
2012 |
dc.date.none.fl_str_mv |
2012-09-01 2022-04-29T04:59:18Z 2022-04-29T04:59:18Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://dx.doi.org/10.1179/1749514812Z.00000000025 International Heat Treatment and Surface Engineering, v. 6, n. 3, p. 103-106, 2012. 1749-5148 1749-5156 http://hdl.handle.net/11449/226975 10.1179/1749514812Z.00000000025 2-s2.0-84866692673 |
url |
http://dx.doi.org/10.1179/1749514812Z.00000000025 http://hdl.handle.net/11449/226975 |
identifier_str_mv |
International Heat Treatment and Surface Engineering, v. 6, n. 3, p. 103-106, 2012. 1749-5148 1749-5156 10.1179/1749514812Z.00000000025 2-s2.0-84866692673 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
International Heat Treatment and Surface Engineering |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
103-106 |
dc.source.none.fl_str_mv |
Scopus reponame:Repositório Institucional da UNESP instname:Universidade Estadual Paulista (UNESP) instacron:UNESP |
instname_str |
Universidade Estadual Paulista (UNESP) |
instacron_str |
UNESP |
institution |
UNESP |
reponame_str |
Repositório Institucional da UNESP |
collection |
Repositório Institucional da UNESP |
repository.name.fl_str_mv |
Repositório Institucional da UNESP - Universidade Estadual Paulista (UNESP) |
repository.mail.fl_str_mv |
|
_version_ |
1799964600755552256 |