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AVALIAÇÃO DA ADESÃO DE REVESTIMENTOS OBTIDOS ATRAVÉS DA TÉCNICA DE ASPERSÃO TÉRMICA PELO MÉTODO DE INDENTAÇÃO INTERFACIAL
(CENTRO FEDERAL DE EDUCAÇÃO TECNOLÓGICA CELSO SUCKOW DA FONSECA, 20/03/2026) FERNANDO JOSE ANTUNES; RICARDO ALEXANDRE AMAR DE AGUIAR; HECTOR REYNALDO MENESES COSTA; RICARDO ALEXANDRE AMAR DE AGUIAR; HECTOR REYNALDO MENESES COSTA; FELIPE DO CARMO AMORIM; HUMBERTO NOGUEIRA FARNEZE; DANIEL KIOSHI KAWASAKI CAVALCANTI; GERONIMO PEREZ
This study evaluated the interfacial adhesion between SAE 1020 carbon steel substrate and three coatings produced by electric arc thermal spraying (FeCoCrNi, FeCr and FeCoCr). The methodology employed the Chicot et al. model applied to the Vickers interfacial indentation test to estimate interfacial fracture toughness. Microstructural characterization was performed by optical microscopy (OM) and scanning electron mi- croscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDS), including image processing for porosity and oxide quantification and crack morphology analysis. Residual stresses were assessed by X-ray diffraction (XRD) in the coating, interface and substrate regions. Hardness (H) was determined by Vickers microhardness (HV), and Young’s modulus (E) was obtained by nanoindentation. The H and E values were used to calculate the (E/H)I ratio in the Chicot/Lesage model. The microstructure exhibited low porosity and reduced oxide content. The apparent interfacial fracture toughness (K), estimated by the Chicot/Lesage model, was 1.05, 1.10 and 1.17 MPa·m¹ᐟ² for FeCoCrNi, FeCr and FeCoCr, respectively, with FeCoCr showing the highest crack propagation resistance. Microhardness ranged from 808 to 978 HV, and Young’s modu- lus from 129 to 183 GPa. Compressive residual stresses up to −240 MPa at the interface contributed to adhesion improvement, corroborating hardness data. Experimental results agreed with numerical simulations performed using the finite element method (FEM) in ANSYS software, with deviations between 1% and 11%, validating the interfacial in- dentation method as a robust tool and, in this case, more representative than ASTM C633 [4] tensile adhesion testing, demonstrating its viability as a simple and cost- effective alternative to the standardized test.
COMPORTAMENTO MICROESTRUTURAL E MECÂNICO DA ZONA TERMICAMENTE AFETADA DE AÇOS API 5L X80S E X100 SOLDADOS PELO PROCESSO GMAW COM ELETRODO ROTATIVO
(CENTRO FEDERAL DE EDUCAÇÃO TECNOLÓGICA CELSO SUCKOW DA FONSECA, 19/03/2026) GILMAR ZACCA BATISTA; JORGE CARLOS FERREIRA JORGE; LUIS FELIPE GUIMARAES DE SOUZA; JORGE CARLOS FERREIRA JORGE; LUIS FELIPE GUIMARAES DE SOUZA; MATHEUS CAMPOLINA MENDES; TATIANE DE CAMPOS CHUVAS; LEONARDO SALES ARAUJO; RAFAELLA MARTINS RIBEIRO
This work investigates the effect of GMAW welding process with a rotating electrode on the microstructural and mechanical behavior of the heat-affected zone of API 5L X80S and X100 steels. The study was structured into three distinct steps: the first step involved bead-on-pipe deposition to evaluate the microstructural behavior of the HAZ of these steels as a function of different heat input levels and rotating frequency variations, as well as to define initial parameters for the subsequent steps; the second step compared the geometric effects of the GMAW and GMAW-RE processes on narrow gap welded joints; and the third step analyzed the effect of the rotating process on the microstructure and mechanical properties of these steels. The HAZ was analyzed using optical microscopy, scanning electron microscopy, EBSD, Charpy-V impact testing, tensile testing, and microhardness measurements. The results revealed that X80S and X100 steels are more sensitive to variations in heat input than to changes in rotating frequency. It was observed that X80S steel was more affected by the rotating process than X100 steel, resulting in welded joints with geometric characteristics more favorable to reducing lack of sidewall fusion. Furthermore, it was found that both steels can be welded across a wide range of rotating speeds without impairing the mechanical properties of the HAZ.
PROPRIEDADES MECÂNICAS E MICROESTRUTURAIS DE REVESTIMENTOS METÁLICOS COM A SUPERLIGA DE NÍQUEL INCONEL 625 OBTIDOS PELOS PROCESSOS ARAME TUBULAR, ELETROESCÓRIA E ELETRODO REVESTIDO
(CENTRO FEDERAL DE EDUCAÇÃO TECNOLÓGICA CELSO SUCKOW DA FONSECA, 16/12/2015) CAMILA PEREIRA ALVARAES; JORGE CARLOS FERREIRA JORGE; JORGE CARLOS FERREIRA JORGE; HECTOR REYNALDO MENESES COSTA; LUIS FELIPE GUIMARAES DE SOUZA; LEONARDO SALES ARAUJO
Revestimentos por soldagem têm sido amplamente utilizados na indústria de Óleo e Gás com a finalidade de ampliar a vida útil de equipamentos submetidos a ambientes corrosivos. O presente trabalho tem como objetivo avaliar o desempenho mecânico e microestrutural de revestimentos metálicos com a superliga de níquel INCONEL 625 e o aço ASTM 516 Gr.70 depositados através dos procedimentos de soldagem arame tubular, eletroescória e eletrodo revestido. Uma análise microestrutural foi realizada através de microscopia óptica e microscopia eletrônica de varredura onde foi possível verificar a presença de zonas parcialmente diluídas ao longo da interface, além de notar a predominância de microestrutura austenítica no metal de solda e observar a precipitação de fases secundárias nessa região. As fases secundárias, no entanto, não apresentaram efeitos deletérios ao revestimento. Além disso, um perfil de microdureza de todas as amostras analisadas foi traçado, bem como o perfil de análise química dos revestimentos. Os valores obtidos através da analise da microdureza se mostraram de acordo com a literatura e com o exigido por normas. As macrografias e as análises químicas possibilitaram avaliar a diluição de cada revestimento. Os valores encontrados estão em concordância com os valores encontrados em diferentes trabalhos da literatura. Os procedimentos adotados no presente estudo se mostraram adequados para a deposição de revestimentos metálicos. Adicionalmente, notou-se uma maior produtividade apresentada pelo procedimento eletroescória o que torna esse procedimento adequado para o revestimento de grandes áreas ou peças. O procedimento eletrodo revestido, estudado para a ocasião de reparos, também se mostrou adequado para tal aplicação.
COMPORTAMENTO MECÂNICO E MICROESTRUTURAL DA ZTA DE JUNTA SOLDADA DE AÇO API 5L GRAU X80
(CENTRO FEDERAL DE EDUCAÇÃO TECNOLÓGICA CELSO SUCKOW DA FONSECA, 06/12/2019) THIAGO RODRIGUES CARBOS; JORGE CARLOS FERREIRA JORGE; JORGE CARLOS FERREIRA JORGE; IVANI DE SOUZA BOTT; LEONARDO SALES ARAUJO; LUIS FELIPE GUIMARAES DE SOUZA; MATHEUS CAMPOLINA MENDES
Over the last 15 years, approximately, the weldability of API 5L X80 steels has been object of extensive research and, therefore, a significant amount of material available in the literature. However, the available data on mechanical properties and acceptance criteria for qualification of welding procedures are still limited, particularly, when it comes to the low toughness found in the coarse grain region of ZTA (RGGZTA), which according to the literature is attributed to the presence of AM (austenite-martensite) microconstituents. The objective of this work is to evaluate the mechanical and microstructural properties of the heat affected zone (HAZ) of API 5L X80 steel manufactured by controlled rolling without accelerated cooling in the welded state and subjected to post weld heat treatment (PWHT), to evaluate the critical region of the ZTA, as well as the microstructural aspects involved, to discuss about the effectiveness of the usual requirements for the approval of the procedures for the safe operation of industrial equipment and suggest possible modifications to the usual procedure for greater precision in the evaluation of procedures involving API steels. For this, a circumferential joint by the shielded metal arc welding (SMAW) process was used. Charpy-V tests, hardness and microhardness tests were performed to evaluate the mechanical properties, and optical microscopy and scanning electron microscopy for microstructural characterization, in addition to the macrography. The results show high impact toughness values at the positions required by standard for approval of welding procedures. However, an additional experiment performed at 0.5mm from the fusion line revealed the occurrence of toughness values below the specified minimum, due to the presence of mixture of MA constituents and carbides decorating the prior austenite grainsize.
PRÁTICAS DISCIPLINARES IMPLICADAS NO RELATÓRIO FIGUEIREDO: PERSPECTIVAS PSICOLÓGICAS NO CONTROLE ÉTNICO-SOCIAL DE ÍNDIOS DURANTE A DITADURA MILITAR
(CENTRO FEDERAL DE EDUCAÇÃO TECNOLÓGICA CELSO SUCKOW DA FONSECA, 2016) ANDRE LUIS DE OLIVEIRA DE SANT'ANNA; ALEXANDRE DE CARVALHO CASTRO; ALEXANDRE DE CARVALHO CASTRO; ALVARO DE OLIVEIRA SENRA; JOANA D'ARC FERNANDES FERRAZ; JOSE RIBAMAR BESSA
The purpose of this research was to analyze, from the perspective of social psychology, disciplinary records relating to indigenous peoples as described in the Figueiredo report, considering the ethnic and social control exercised during the military dictatorship years in Brazil. In this sense, it follows from the context in which the Commission National Truth, through the work of the indigenous stem, has identified a set of documents, reported missing since the sixties: The Figueiredo report, which deals with the investigation of a Commission of Inquiry on allegations of crimes committed by the very Indigenous Protection Service against indigenous population. In fact, these social control mechanisms are not very well known in Brazil; however, they foster relevant studies and research on the surveillance of conduct seen as deviant. As the aim is to verify the aspects of "source" and "imperativeness" of such disciplinary measures, the theoretical option methodology is based on the genealogy of Foucault, as well as his principles on disciplinary practices. Identifying disciplinary practices used with Indians in the period of dictatorship as described in Figueiredo report will therefore be important to understand how native Brazilian's bodies have been assaulted as a result of social control strategies.