Estudo da microestrutura dos aços inoxidáveis austeníticos : Aisi 316L e 317L soldados pelo Processo TIG
Autor(a) principal: | |
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Data de Publicação: | 2019 |
Tipo de documento: | Dissertação |
Idioma: | por |
Título da fonte: | Biblioteca Digital de Teses e Dissertações do Mackenzie |
Texto Completo: | http://dspace.mackenzie.br/handle/10899/26434 |
Resumo: | Stainless steels were developed in the beginning of the 20th century and have been constantly improved since then. As other metal alloys, stainless steels are classified according to the chemical composition Austenitic stainless steels represent 2/3 of the world's stainless steel production due to their resistance to corrosion, oxidation, hot mechanical strength, workability and weldability. These properties are obtained by the addition of different alloying elements. In industry, the welding process is one of the most applied in austenitic stainless steels. Both the alloying elements and the different processes have a direct influence on the microstructure of the steel. The austenitic stainless steels present predominantly austenitic microstructure, but during solidification this structure is altered due to the formation of delta ferrite, derived from the segregation of stabilizing elements of the ferrite. The quantification of delta ferrite is extremely important for properties related to ductility, crack susceptibility and mechanical resistance. In addition, intermetallic phases, such as sigma, precipitates from the delta ferrite . There are several types of reagents used to perform chemical / electrolytic etching to reveal these phases in the microstructure. This work studied a methodology for the microstructural characterization of AISI 316L and AISI 317L austenitic alloys, welded by the GTAW process and submitted to heat treatments with different times, in order to reveal δ ferrite and intermetallic phases, sigma ( σ), chi (χ) and the Laves phase (η). AISI 316L and AISI 317L alloys were selected because they are characteristics for applications requiring high corrosion resistance. Both AISI 316L and AISI 317L alloys were solubilized at 1080 ˚ C with different times. Samples of both materials were analyzed in the base metal and in the weld metal, in the condition of welding and without heat treatment. According to Vander Voort electrolytic etching using the reactants in the proportions: 10% of oxalic acid, 10% KOH and 20% NaOH, all subjected to a voltage of 6V for 60s, reveal ferrite δ and some intermetallic phases such as sigma phase. In addition, a study on pitting corrosion was carried out by the potentiodynamic cyclic polarization method. It was concluded as well as the bibliographical references that the presence of intermetallic phases directly affects the resistance to pitting corrosion. The samples without heat treatment presented higher percentage of delta ferrite and were more resistant to pitting corrosion. |
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2019-09-11T18:18:02Z2020-05-28T18:18:43Z2020-05-28T18:18:43Z2019-02-01PEREIRA, Karla Guimarães Santos. Estudo da microestrutura dos aços inoxidáveis austeníticos : Aisi 316L e 317L soldados pelo Processo TIG. 2019. 151 f. Dissertação (Engenharia de Materiais e Nanotecnologia) - Universidade Presbiteriana Mackenzie, São Paulo.http://dspace.mackenzie.br/handle/10899/26434Stainless steels were developed in the beginning of the 20th century and have been constantly improved since then. As other metal alloys, stainless steels are classified according to the chemical composition Austenitic stainless steels represent 2/3 of the world's stainless steel production due to their resistance to corrosion, oxidation, hot mechanical strength, workability and weldability. These properties are obtained by the addition of different alloying elements. In industry, the welding process is one of the most applied in austenitic stainless steels. Both the alloying elements and the different processes have a direct influence on the microstructure of the steel. The austenitic stainless steels present predominantly austenitic microstructure, but during solidification this structure is altered due to the formation of delta ferrite, derived from the segregation of stabilizing elements of the ferrite. The quantification of delta ferrite is extremely important for properties related to ductility, crack susceptibility and mechanical resistance. In addition, intermetallic phases, such as sigma, precipitates from the delta ferrite . There are several types of reagents used to perform chemical / electrolytic etching to reveal these phases in the microstructure. This work studied a methodology for the microstructural characterization of AISI 316L and AISI 317L austenitic alloys, welded by the GTAW process and submitted to heat treatments with different times, in order to reveal δ ferrite and intermetallic phases, sigma ( σ), chi (χ) and the Laves phase (η). AISI 316L and AISI 317L alloys were selected because they are characteristics for applications requiring high corrosion resistance. Both AISI 316L and AISI 317L alloys were solubilized at 1080 ˚ C with different times. Samples of both materials were analyzed in the base metal and in the weld metal, in the condition of welding and without heat treatment. According to Vander Voort electrolytic etching using the reactants in the proportions: 10% of oxalic acid, 10% KOH and 20% NaOH, all subjected to a voltage of 6V for 60s, reveal ferrite δ and some intermetallic phases such as sigma phase. In addition, a study on pitting corrosion was carried out by the potentiodynamic cyclic polarization method. It was concluded as well as the bibliographical references that the presence of intermetallic phases directly affects the resistance to pitting corrosion. The samples without heat treatment presented higher percentage of delta ferrite and were more resistant to pitting corrosion.Os aços inoxidáveis foram desenvolvidos no início do século XX, desde então encontram-se em constante aprimoramento. Como as ligas metálicas os aços inoxidáveis são classificados de acordo com a composição química, sendo os aços inoxidáveis austeníticos responsáveis por 2/3 da produção mundial de aço inoxidável, devido à sua resistência à corrosão à oxidação, resistência mecânica a quente, trabalhabilidade e soldabilidade. Essas propriedades são adquiridas com adição de diferentes elementos de liga. Na indústria o processo de soldagem é um dos mais aplicados em aços inoxidáveis austeníticos. Tanto os elementos de liga quanto os diferentes processamentos influenciam de maneira direta na microestrutura do aço. Os aços inoxidáveis austeníticos apresentam microestrutura predominante austenítica, porém durante a solidificação esta estrutura é alterada devido a formação de ferrita delta, derivada da segregação de elementos estabilizadores da ferrita. A quantificação da ferrita delta é de suma importância para as propriedades de ductilidade, susceptibilidade de trincas e resistência mecânica. Além disso fases intermetálicas como a sigma precipitam a partir da ferrita delta. Existem diversos tipos de reagentes utilizados para realizar ataques químicos/eletrolíticos para revelar essas fases na microestrutura. Este trabalho estudou uma metodologia para a caracterização microestrutural das ligas de aços inoxidáveis austeníticos AISI 316L e AISI 317L, soldados pelo processo GTAW e submetidos a tratamentos térmicos com diferentes tempos, com o intuito de revelar a ferrita δ, e as fases intermetálicas, sigma (σ), chi (χ) e a fase de Laves (η). As ligas AISI 316L e AISI 317L foram selecionadas por serem características para a aplicações que exigem alta resistência à corrosão. Ambas as ligas AISI 316L e AISI 317L foram solubilizadas a 1080 ˚ C, com diferentes tempos. Analisaram-se amostras de ambos materiais no metal de base e na solda, na condição de soldado e sem tratamento térmico. Segundo Vander Voort ataques eletrolíticos utilizando os reagentes nas proporções: 10% de ácido oxálico, 10% KOH e 20%NaOH, todas submetidas a uma tensão de 6V durante 60s, revelam a ferrita δ e algumas fases intermetálicas com a σ (sigma). Além disso, realizou-se estudo quanto a corrosão por pite pelo método de polarização cíclica potenciodinâmica. Concluiu-se assim como as referências bibliográficas que a presença de fases intermetálicas afeta diretamente na resistência à corrosão por pite. As amostras sem tratamento térmico apresentaram maior percentual de ferrita delta e mostraramse mais resistentes a corrosão por pite.Coordenação de Aperfeiçoamento de Pessoal de Nível Superiorapplication/pdfporUniversidade Presbiteriana MackenzieEngenharia de Materiais e NanotecnologiaUPMBrasilEscola de Engenharia Mackenzie (EE)http://creativecommons.org/licenses/by-nc-nd/4.0/info:eu-repo/semantics/openAccesscorrosão por pitefases intermetálicasaço inoxidávelCNPQ::ENGENHARIAS::ENGENHARIA MECANICACNPQ::ENGENHARIAS::ENGENHARIA DE MATERIAIS E METALURGICA::METALURGIA FISICA::CORROSAOEstudo da microestrutura dos aços inoxidáveis austeníticos : Aisi 316L e 317L soldados pelo Processo TIGinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/masterThesisTerence, Mauro Cesarhttp://lattes.cnpq.br/0310437722311048Massi, MarcosMonteiro, Waldemar Alfredohttp://lattes.cnpq.br/3120596267536849Pereira, Karla Guimarães Santoshttp://tede.mackenzie.br/jspui/retrieve/19372/Karla%20Guima%c3%a3es%20Santos%20Pereira.pdf.jpghttp://tede.mackenzie.br/jspui/bitstream/tede/4012/5/Karla%20Guima%C3%A3es%20Santos%20Pereira.pdfpitting corrosionintermetallic phasesstainless steelsreponame:Biblioteca Digital de Teses e Dissertações do Mackenzieinstname:Universidade Presbiteriana Mackenzie (MACKENZIE)instacron:MACKENZIE10899/264342020-05-28 15:18:43.075Biblioteca Digital de Teses e Dissertaçõeshttp://tede.mackenzie.br/jspui/PRI |
dc.title.por.fl_str_mv |
Estudo da microestrutura dos aços inoxidáveis austeníticos : Aisi 316L e 317L soldados pelo Processo TIG |
title |
Estudo da microestrutura dos aços inoxidáveis austeníticos : Aisi 316L e 317L soldados pelo Processo TIG |
spellingShingle |
Estudo da microestrutura dos aços inoxidáveis austeníticos : Aisi 316L e 317L soldados pelo Processo TIG Pereira, Karla Guimarães Santos corrosão por pite fases intermetálicas aço inoxidável CNPQ::ENGENHARIAS::ENGENHARIA MECANICA CNPQ::ENGENHARIAS::ENGENHARIA DE MATERIAIS E METALURGICA::METALURGIA FISICA::CORROSAO |
title_short |
Estudo da microestrutura dos aços inoxidáveis austeníticos : Aisi 316L e 317L soldados pelo Processo TIG |
title_full |
Estudo da microestrutura dos aços inoxidáveis austeníticos : Aisi 316L e 317L soldados pelo Processo TIG |
title_fullStr |
Estudo da microestrutura dos aços inoxidáveis austeníticos : Aisi 316L e 317L soldados pelo Processo TIG |
title_full_unstemmed |
Estudo da microestrutura dos aços inoxidáveis austeníticos : Aisi 316L e 317L soldados pelo Processo TIG |
title_sort |
Estudo da microestrutura dos aços inoxidáveis austeníticos : Aisi 316L e 317L soldados pelo Processo TIG |
author |
Pereira, Karla Guimarães Santos |
author_facet |
Pereira, Karla Guimarães Santos |
author_role |
author |
dc.contributor.advisor1.fl_str_mv |
Terence, Mauro Cesar |
dc.contributor.advisor1Lattes.fl_str_mv |
http://lattes.cnpq.br/0310437722311048 |
dc.contributor.referee1.fl_str_mv |
Massi, Marcos |
dc.contributor.referee2.fl_str_mv |
Monteiro, Waldemar Alfredo |
dc.contributor.authorLattes.fl_str_mv |
http://lattes.cnpq.br/3120596267536849 |
dc.contributor.author.fl_str_mv |
Pereira, Karla Guimarães Santos |
contributor_str_mv |
Terence, Mauro Cesar Massi, Marcos Monteiro, Waldemar Alfredo |
dc.subject.por.fl_str_mv |
corrosão por pite fases intermetálicas aço inoxidável |
topic |
corrosão por pite fases intermetálicas aço inoxidável CNPQ::ENGENHARIAS::ENGENHARIA MECANICA CNPQ::ENGENHARIAS::ENGENHARIA DE MATERIAIS E METALURGICA::METALURGIA FISICA::CORROSAO |
dc.subject.cnpq.fl_str_mv |
CNPQ::ENGENHARIAS::ENGENHARIA MECANICA CNPQ::ENGENHARIAS::ENGENHARIA DE MATERIAIS E METALURGICA::METALURGIA FISICA::CORROSAO |
description |
Stainless steels were developed in the beginning of the 20th century and have been constantly improved since then. As other metal alloys, stainless steels are classified according to the chemical composition Austenitic stainless steels represent 2/3 of the world's stainless steel production due to their resistance to corrosion, oxidation, hot mechanical strength, workability and weldability. These properties are obtained by the addition of different alloying elements. In industry, the welding process is one of the most applied in austenitic stainless steels. Both the alloying elements and the different processes have a direct influence on the microstructure of the steel. The austenitic stainless steels present predominantly austenitic microstructure, but during solidification this structure is altered due to the formation of delta ferrite, derived from the segregation of stabilizing elements of the ferrite. The quantification of delta ferrite is extremely important for properties related to ductility, crack susceptibility and mechanical resistance. In addition, intermetallic phases, such as sigma, precipitates from the delta ferrite . There are several types of reagents used to perform chemical / electrolytic etching to reveal these phases in the microstructure. This work studied a methodology for the microstructural characterization of AISI 316L and AISI 317L austenitic alloys, welded by the GTAW process and submitted to heat treatments with different times, in order to reveal δ ferrite and intermetallic phases, sigma ( σ), chi (χ) and the Laves phase (η). AISI 316L and AISI 317L alloys were selected because they are characteristics for applications requiring high corrosion resistance. Both AISI 316L and AISI 317L alloys were solubilized at 1080 ˚ C with different times. Samples of both materials were analyzed in the base metal and in the weld metal, in the condition of welding and without heat treatment. According to Vander Voort electrolytic etching using the reactants in the proportions: 10% of oxalic acid, 10% KOH and 20% NaOH, all subjected to a voltage of 6V for 60s, reveal ferrite δ and some intermetallic phases such as sigma phase. In addition, a study on pitting corrosion was carried out by the potentiodynamic cyclic polarization method. It was concluded as well as the bibliographical references that the presence of intermetallic phases directly affects the resistance to pitting corrosion. The samples without heat treatment presented higher percentage of delta ferrite and were more resistant to pitting corrosion. |
publishDate |
2019 |
dc.date.accessioned.fl_str_mv |
2019-09-11T18:18:02Z 2020-05-28T18:18:43Z |
dc.date.issued.fl_str_mv |
2019-02-01 |
dc.date.available.fl_str_mv |
2020-05-28T18:18:43Z |
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.citation.fl_str_mv |
PEREIRA, Karla Guimarães Santos. Estudo da microestrutura dos aços inoxidáveis austeníticos : Aisi 316L e 317L soldados pelo Processo TIG. 2019. 151 f. Dissertação (Engenharia de Materiais e Nanotecnologia) - Universidade Presbiteriana Mackenzie, São Paulo. |
dc.identifier.uri.fl_str_mv |
http://dspace.mackenzie.br/handle/10899/26434 |
identifier_str_mv |
PEREIRA, Karla Guimarães Santos. Estudo da microestrutura dos aços inoxidáveis austeníticos : Aisi 316L e 317L soldados pelo Processo TIG. 2019. 151 f. Dissertação (Engenharia de Materiais e Nanotecnologia) - Universidade Presbiteriana Mackenzie, São Paulo. |
url |
http://dspace.mackenzie.br/handle/10899/26434 |
dc.language.iso.fl_str_mv |
por |
language |
por |
dc.rights.driver.fl_str_mv |
http://creativecommons.org/licenses/by-nc-nd/4.0/ info:eu-repo/semantics/openAccess |
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http://creativecommons.org/licenses/by-nc-nd/4.0/ |
eu_rights_str_mv |
openAccess |
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application/pdf |
dc.publisher.none.fl_str_mv |
Universidade Presbiteriana Mackenzie |
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Engenharia de Materiais e Nanotecnologia |
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UPM |
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Brasil |
dc.publisher.department.fl_str_mv |
Escola de Engenharia Mackenzie (EE) |
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Universidade Presbiteriana Mackenzie |
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reponame:Biblioteca Digital de Teses e Dissertações do Mackenzie instname:Universidade Presbiteriana Mackenzie (MACKENZIE) instacron:MACKENZIE |
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Universidade Presbiteriana Mackenzie (MACKENZIE) |
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MACKENZIE |
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MACKENZIE |
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Biblioteca Digital de Teses e Dissertações do Mackenzie |
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Biblioteca Digital de Teses e Dissertações do Mackenzie |
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