O efeito do encruamento em aços inoxidáveis submetidos ao tratamento de nitretação
Autor(a) principal: | |
---|---|
Data de Publicação: | 2012 |
Tipo de documento: | Dissertação |
Idioma: | por |
Título da fonte: | Biblioteca Digital de Teses e Dissertações do Mackenzie |
Texto Completo: | http://dspace.mackenzie.br/handle/10899/24160 |
Resumo: | This paper presents an evaluation of the effects of strain hardening on the kinetics of nitriding thermochemical treatment of alloys of ferritic steels AISI 430 and AISI 439 for different degrees of plastic deformation. The technique used to apply the plastic deformation level was increased by a universal tensile machine. Then we proceeded to apply the processes of gas nitriding, in salt baths and plasma, the alloys in the annealed condition and for different degrees of hardening. The samples were characterized by optical microscopy, scanning electron microscopy, hardness tests and examination of the microhardness profile of the layers. It also employed the technique of X-ray diffraction in order to determine the phases present in the nitrided layer. As a result of this study, it was found that the hardening has no effect on the kinetics of nitriding processes, nor levels of hardness achieved in the nitrided layer. The layer thickness was raised to a gas nitriding process, which besides the exposure time at temperature was held at temperature higher than the other processes studied. This study also presents the results of microstructure and curves of the percentage of nitrogen and carbon depending on the depth of the nitrided layer. Note that the nitrogen concentration decreases with depth as approaching the base metal. Carbon, in turn, is pushed into the sample, providing a decarburization in the region enriched in nitrogen and carbon accumulation in the regions just below the nitrided layer. The spectra of X-ray diffraction corresponding to the nitrided layers of steels 430 and 439 indicated the presence of CrN precipitate rich in nitrogen. The alloy 430 suffered heavy attack to a depth of about 30 Um on the other hand the alloy 439 had the region with little predominance of attack, with small volume fractions of more intense attack. The hardness levels of light and dark regions were similars, around 1000 HV, indicating an efficient mechanism of precipitation hardening. It concluded that the chromium nitride is present in both regions, and the highest attack can be related to a discontinuous precipitation process, probably due to iron nitride Fe3N, contrary to what was found in the literature. |
id |
UPM_1f25568ed567a3d6bc3769fd3336f0aa |
---|---|
oai_identifier_str |
oai:dspace.mackenzie.br:10899/24160 |
network_acronym_str |
UPM |
network_name_str |
Biblioteca Digital de Teses e Dissertações do Mackenzie |
repository_id_str |
10277 |
spelling |
2016-03-15T19:36:36Z2020-05-28T18:07:25Z2013-05-292020-05-28T18:07:25Z2012-08-02http://dspace.mackenzie.br/handle/10899/24160This paper presents an evaluation of the effects of strain hardening on the kinetics of nitriding thermochemical treatment of alloys of ferritic steels AISI 430 and AISI 439 for different degrees of plastic deformation. The technique used to apply the plastic deformation level was increased by a universal tensile machine. Then we proceeded to apply the processes of gas nitriding, in salt baths and plasma, the alloys in the annealed condition and for different degrees of hardening. The samples were characterized by optical microscopy, scanning electron microscopy, hardness tests and examination of the microhardness profile of the layers. It also employed the technique of X-ray diffraction in order to determine the phases present in the nitrided layer. As a result of this study, it was found that the hardening has no effect on the kinetics of nitriding processes, nor levels of hardness achieved in the nitrided layer. The layer thickness was raised to a gas nitriding process, which besides the exposure time at temperature was held at temperature higher than the other processes studied. This study also presents the results of microstructure and curves of the percentage of nitrogen and carbon depending on the depth of the nitrided layer. Note that the nitrogen concentration decreases with depth as approaching the base metal. Carbon, in turn, is pushed into the sample, providing a decarburization in the region enriched in nitrogen and carbon accumulation in the regions just below the nitrided layer. The spectra of X-ray diffraction corresponding to the nitrided layers of steels 430 and 439 indicated the presence of CrN precipitate rich in nitrogen. The alloy 430 suffered heavy attack to a depth of about 30 Um on the other hand the alloy 439 had the region with little predominance of attack, with small volume fractions of more intense attack. The hardness levels of light and dark regions were similars, around 1000 HV, indicating an efficient mechanism of precipitation hardening. It concluded that the chromium nitride is present in both regions, and the highest attack can be related to a discontinuous precipitation process, probably due to iron nitride Fe3N, contrary to what was found in the literature.O presente trabalho apresenta uma avaliação dos efeitos de encruamento na cinética do tratamento termoquímico de nitretação em ligas de aços inoxidáveis ferríticos AISI 430 e AISI 439 para diferentes graus de deformação plástica. A técnica empregada para se aplicar a deformação plástica em nível crescente foi por meio de uma máquina universal de tração. Em seguida procedeu-se a aplicação dos processos de nitretação gasosa, em banhos de sais e por plasma, nas ligas no estado recozido e para os diferentes graus de encruamento. As amostras foram caracterizadas por microscopia óptica, microscopia eletrônica de varredura, ensaios de dureza e levantamento do perfil de microdureza das camadas. Foi empregada também a técnica de difração de raios-X, com o objetivo de se determinar quais as fases presentes na camada nitretada. Como resultado principal deste estudo, concluiu-se que o encruamento não apresentou nenhum efeito na cinética dos processos de nitretação, nem tão pouco nos níveis de dureza atingidos nas camadas nitretadas. A espessura da camada foi maior para o processo de nitretação a gás, que além do tempo em exposição em temperatura, foi realizada em temperatura superior aos outros processos estudados. Este estudo também apresenta os resultados de microestrutura e as curvas de percentual de nitrôgenio e carbono em função da profundidade de camada nitretada. Nota-se que a concentração de nitrogênio diminui com a profundidade à medida que se aproxima do metal base. O carbono, por seu turno, é empurrado para dentro da amostra, promovendo uma descarbonetação na região enriquecida em nitrogênio, e um acúmulo de carbono nas regiões logo abaixo da camada nitretada. Os espectros de difração de raios-X correspondentes às camadas nitretadas dos aços 430 e 439, indicaram a presença do precipitado rico em nitrogênio CrN. A liga 430 sofreu ataque intenso até uma profundidade da ordem de 30 Um; já a liga 439 apresentava predominância de região com pouco ataque, com pequena fração volumétrica de ataque mais intenso. Os níveis de dureza da região clara e escura eram similares, por volta de 1000 HV, indicando um eficiente mecanismo de endurecimento por precipitação. Infere-se que o nitreto de cromo se faz presente nas duas regiões, sendo que o maior ataque pode estar relacionado a um processo de precipitação descontínua, provavelmente associado ao nitreto de ferro Fe3N, contrariamente ao que se encontrou na literatura.Proact Empreendimentos Tecnológicos S/C Ltdaapplication/pdfporUniversidade Presbiteriana MackenzieEngenharia de MateriaisUPMBREngenharia de Materiaisaço inoxidável ferríticonitretaçãoencruamentodifração de raios-xferritic stainless steelnitridingcold workx-ray diffractionCNPQ::ENGENHARIAS::ENGENHARIA DE MATERIAIS E METALURGICAO efeito do encruamento em aços inoxidáveis submetidos ao tratamento de nitretaçãoinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisVatavuk, Janhttp://lattes.cnpq.br/2607688973456560Andrade, Arnaldo Homobono Paes dehttp://lattes.cnpq.br/1605291530127961Couto, Antonio Augustohttp://lattes.cnpq.br/2893737202813850http://lattes.cnpq.br/9585084684343546Monte, Mariana Zicari Dihttp://tede.mackenzie.br/jspui/retrieve/3594/Mariana%20Zicari%20Di%20Monte.pdf.jpghttp://tede.mackenzie.br/jspui/bitstream/tede/1328/1/Mariana%20Zicari%20Di%20Monte.pdfinfo:eu-repo/semantics/openAccessreponame:Biblioteca Digital de Teses e Dissertações do Mackenzieinstname:Universidade Presbiteriana Mackenzie (MACKENZIE)instacron:MACKENZIE10899/241602020-05-28 15:07:25.709Biblioteca Digital de Teses e Dissertaçõeshttp://tede.mackenzie.br/jspui/PRI |
dc.title.por.fl_str_mv |
O efeito do encruamento em aços inoxidáveis submetidos ao tratamento de nitretação |
title |
O efeito do encruamento em aços inoxidáveis submetidos ao tratamento de nitretação |
spellingShingle |
O efeito do encruamento em aços inoxidáveis submetidos ao tratamento de nitretação Monte, Mariana Zicari Di aço inoxidável ferrítico nitretação encruamento difração de raios-x ferritic stainless steel nitriding cold work x-ray diffraction CNPQ::ENGENHARIAS::ENGENHARIA DE MATERIAIS E METALURGICA |
title_short |
O efeito do encruamento em aços inoxidáveis submetidos ao tratamento de nitretação |
title_full |
O efeito do encruamento em aços inoxidáveis submetidos ao tratamento de nitretação |
title_fullStr |
O efeito do encruamento em aços inoxidáveis submetidos ao tratamento de nitretação |
title_full_unstemmed |
O efeito do encruamento em aços inoxidáveis submetidos ao tratamento de nitretação |
title_sort |
O efeito do encruamento em aços inoxidáveis submetidos ao tratamento de nitretação |
author |
Monte, Mariana Zicari Di |
author_facet |
Monte, Mariana Zicari Di |
author_role |
author |
dc.contributor.advisor1.fl_str_mv |
Vatavuk, Jan |
dc.contributor.advisor1Lattes.fl_str_mv |
http://lattes.cnpq.br/2607688973456560 |
dc.contributor.referee1.fl_str_mv |
Andrade, Arnaldo Homobono Paes de |
dc.contributor.referee1Lattes.fl_str_mv |
http://lattes.cnpq.br/1605291530127961 |
dc.contributor.referee2.fl_str_mv |
Couto, Antonio Augusto |
dc.contributor.referee2Lattes.fl_str_mv |
http://lattes.cnpq.br/2893737202813850 |
dc.contributor.authorLattes.fl_str_mv |
http://lattes.cnpq.br/9585084684343546 |
dc.contributor.author.fl_str_mv |
Monte, Mariana Zicari Di |
contributor_str_mv |
Vatavuk, Jan Andrade, Arnaldo Homobono Paes de Couto, Antonio Augusto |
dc.subject.por.fl_str_mv |
aço inoxidável ferrítico nitretação encruamento difração de raios-x |
topic |
aço inoxidável ferrítico nitretação encruamento difração de raios-x ferritic stainless steel nitriding cold work x-ray diffraction CNPQ::ENGENHARIAS::ENGENHARIA DE MATERIAIS E METALURGICA |
dc.subject.eng.fl_str_mv |
ferritic stainless steel nitriding cold work x-ray diffraction |
dc.subject.cnpq.fl_str_mv |
CNPQ::ENGENHARIAS::ENGENHARIA DE MATERIAIS E METALURGICA |
description |
This paper presents an evaluation of the effects of strain hardening on the kinetics of nitriding thermochemical treatment of alloys of ferritic steels AISI 430 and AISI 439 for different degrees of plastic deformation. The technique used to apply the plastic deformation level was increased by a universal tensile machine. Then we proceeded to apply the processes of gas nitriding, in salt baths and plasma, the alloys in the annealed condition and for different degrees of hardening. The samples were characterized by optical microscopy, scanning electron microscopy, hardness tests and examination of the microhardness profile of the layers. It also employed the technique of X-ray diffraction in order to determine the phases present in the nitrided layer. As a result of this study, it was found that the hardening has no effect on the kinetics of nitriding processes, nor levels of hardness achieved in the nitrided layer. The layer thickness was raised to a gas nitriding process, which besides the exposure time at temperature was held at temperature higher than the other processes studied. This study also presents the results of microstructure and curves of the percentage of nitrogen and carbon depending on the depth of the nitrided layer. Note that the nitrogen concentration decreases with depth as approaching the base metal. Carbon, in turn, is pushed into the sample, providing a decarburization in the region enriched in nitrogen and carbon accumulation in the regions just below the nitrided layer. The spectra of X-ray diffraction corresponding to the nitrided layers of steels 430 and 439 indicated the presence of CrN precipitate rich in nitrogen. The alloy 430 suffered heavy attack to a depth of about 30 Um on the other hand the alloy 439 had the region with little predominance of attack, with small volume fractions of more intense attack. The hardness levels of light and dark regions were similars, around 1000 HV, indicating an efficient mechanism of precipitation hardening. It concluded that the chromium nitride is present in both regions, and the highest attack can be related to a discontinuous precipitation process, probably due to iron nitride Fe3N, contrary to what was found in the literature. |
publishDate |
2012 |
dc.date.issued.fl_str_mv |
2012-08-02 |
dc.date.available.fl_str_mv |
2013-05-29 2020-05-28T18:07:25Z |
dc.date.accessioned.fl_str_mv |
2016-03-15T19:36:36Z 2020-05-28T18:07:25Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/masterThesis |
format |
masterThesis |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://dspace.mackenzie.br/handle/10899/24160 |
url |
http://dspace.mackenzie.br/handle/10899/24160 |
dc.language.iso.fl_str_mv |
por |
language |
por |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
Universidade Presbiteriana Mackenzie |
dc.publisher.program.fl_str_mv |
Engenharia de Materiais |
dc.publisher.initials.fl_str_mv |
UPM |
dc.publisher.country.fl_str_mv |
BR |
dc.publisher.department.fl_str_mv |
Engenharia de Materiais |
publisher.none.fl_str_mv |
Universidade Presbiteriana Mackenzie |
dc.source.none.fl_str_mv |
reponame:Biblioteca Digital de Teses e Dissertações do Mackenzie instname:Universidade Presbiteriana Mackenzie (MACKENZIE) instacron:MACKENZIE |
instname_str |
Universidade Presbiteriana Mackenzie (MACKENZIE) |
instacron_str |
MACKENZIE |
institution |
MACKENZIE |
reponame_str |
Biblioteca Digital de Teses e Dissertações do Mackenzie |
collection |
Biblioteca Digital de Teses e Dissertações do Mackenzie |
repository.name.fl_str_mv |
|
repository.mail.fl_str_mv |
|
_version_ |
1757177228685213696 |