Pub Date : 2021-01-01DOI: 10.4322/2176-1523.20212463
M. Cunha, R. Carbas, E. Marques, A. Akhavan‐Safar, L. F. Silva
The aim of this study is to characterize the fatigue behaviour of a structural epoxy adhesive loaded in mixedmode conditions. To this effect, several fracture tests were carried out: Double Cantilever Beam (DCB) for pure mode I, End Notched Flexure (ENF) for pure mode II, and mixed-mode testing, using an apparatus that enables the application of mixed-mode loadings to an adhesive and with high strength steel adherends. The fracture envelope was calculated using experimental data and it was found to be compatible with a quadratic criterion. A novel quadratic law criterion was developed to fit the envelope. The fatigue behaviour was studied recurring to fatigue crack growth curves for the same types of loads studied in the quasi-static tests. A relationship between mixed-mode phase angle and the Paris law slope was found, where the existence of mode II loads was found to delay crack propagation. By performing fatigue tests at 60% and 80% of the maximum load, it was noticed that increasing the load leads to the increase of the threshold energy release rate values.
{"title":"Fatigue behaviour of an epoxy adhesive under mixed-mode conditions","authors":"M. Cunha, R. Carbas, E. Marques, A. Akhavan‐Safar, L. F. Silva","doi":"10.4322/2176-1523.20212463","DOIUrl":"https://doi.org/10.4322/2176-1523.20212463","url":null,"abstract":"The aim of this study is to characterize the fatigue behaviour of a structural epoxy adhesive loaded in mixedmode conditions. To this effect, several fracture tests were carried out: Double Cantilever Beam (DCB) for pure mode I, End Notched Flexure (ENF) for pure mode II, and mixed-mode testing, using an apparatus that enables the application of mixed-mode loadings to an adhesive and with high strength steel adherends. The fracture envelope was calculated using experimental data and it was found to be compatible with a quadratic criterion. A novel quadratic law criterion was developed to fit the envelope. The fatigue behaviour was studied recurring to fatigue crack growth curves for the same types of loads studied in the quasi-static tests. A relationship between mixed-mode phase angle and the Paris law slope was found, where the existence of mode II loads was found to delay crack propagation. By performing fatigue tests at 60% and 80% of the maximum load, it was noticed that increasing the load leads to the increase of the threshold energy release rate values.","PeriodicalId":53327,"journal":{"name":"Tecnologia em Metalurgia Materiais e Mineracao","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70525803","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.4322/2176-1523.20212519
B. Lopes, J. A. Castro, L. Demuner, A. C. E. Silva
Hydrogen may cause several problems during steel processing. Issues caused or enhanced by hydrogen range from different types of bubbles such as pinholes to breakout during continuous casting. Further down the line, segregation and embrittlement may lead to cracking such as flaking or blistering. These problems impact plant productivity and have cost impacts on equipment maintenance and the need for additional steel treatment. Some of the problems lead to scraping. Although vacuum degassing effectively controls the hydrogen content of steel, it introduces additional costs that are not justifiable for many products. This work aims to identify the main sources of hydrogen in liquid steel in the Ternium Brazil steelmaking plant and to propose a model to decide the need for hydrogen measurement for the degassing process, focusing on steels for which vacuum degassing is not a specification requirement. It is essential for these steels to guarantee a controlled level of dissolved hydrogen to avoid problems, mostly at casting. Once the sources are identified, a model is developed to predict the hydrogen content at the beginning of the secondary metallurgy treatment. Based on the model, it is proposed that hydrogen should be measured or not at this step to decide if vacuum degassing is required to assure safety in casting.
{"title":"A predictive model for hydrogen content in steel in non-degassed heats","authors":"B. Lopes, J. A. Castro, L. Demuner, A. C. E. Silva","doi":"10.4322/2176-1523.20212519","DOIUrl":"https://doi.org/10.4322/2176-1523.20212519","url":null,"abstract":"Hydrogen may cause several problems during steel processing. Issues caused or enhanced by hydrogen range from different types of bubbles such as pinholes to breakout during continuous casting. Further down the line, segregation and embrittlement may lead to cracking such as flaking or blistering. These problems impact plant productivity and have cost impacts on equipment maintenance and the need for additional steel treatment. Some of the problems lead to scraping. Although vacuum degassing effectively controls the hydrogen content of steel, it introduces additional costs that are not justifiable for many products. This work aims to identify the main sources of hydrogen in liquid steel in the Ternium Brazil steelmaking plant and to propose a model to decide the need for hydrogen measurement for the degassing process, focusing on steels for which vacuum degassing is not a specification requirement. It is essential for these steels to guarantee a controlled level of dissolved hydrogen to avoid problems, mostly at casting. Once the sources are identified, a model is developed to predict the hydrogen content at the beginning of the secondary metallurgy treatment. Based on the model, it is proposed that hydrogen should be measured or not at this step to decide if vacuum degassing is required to assure safety in casting.","PeriodicalId":53327,"journal":{"name":"Tecnologia em Metalurgia Materiais e Mineracao","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70526088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.4322/2176-1523.20202452
G. Lemos, D. Buzzatti, C. Amavisca, G. Dalpiaz, M. Paes, L. Kanan, A. Reguly
Deepwater and ultra-deepwater oil and gas exploitation might be challenge due to the fatigue damage at the touchdown zone (TDZ). Therefore, the development of risers with thicker pipe ends (upset end) is a solution to diminish issues related to fatigue through reducing the average axial stress. In the current study, manufacturing of an upset end was carried out by friction welding in an API X65 PLS2 steel pipe with outer diameter of 220 mm. Considering the welding geometry called ‘tube to tube’, pipe sections were machined with different thickness. Thus, in the welding process, the rotational speed was employed in the upset (thicker pipe), while the axial force was applied in the thinner pipe. Hence, this work presents the feasibility of manufacturing an upset end through friction welding and the metallurgical and mechanical properties of the joint. The results showed a suitable welded joint with good top surface appearance and no defects. The samples have not fractured in fatigue tests, which indicate high fatigue life.
{"title":"Manufacturing an upset end by friction welding in an API X65 steel","authors":"G. Lemos, D. Buzzatti, C. Amavisca, G. Dalpiaz, M. Paes, L. Kanan, A. Reguly","doi":"10.4322/2176-1523.20202452","DOIUrl":"https://doi.org/10.4322/2176-1523.20202452","url":null,"abstract":"Deepwater and ultra-deepwater oil and gas exploitation might be challenge due to the fatigue damage at the touchdown zone (TDZ). Therefore, the development of risers with thicker pipe ends (upset end) is a solution to diminish issues related to fatigue through reducing the average axial stress. In the current study, manufacturing of an upset end was carried out by friction welding in an API X65 PLS2 steel pipe with outer diameter of 220 mm. Considering the welding geometry called ‘tube to tube’, pipe sections were machined with different thickness. Thus, in the welding process, the rotational speed was employed in the upset (thicker pipe), while the axial force was applied in the thinner pipe. Hence, this work presents the feasibility of manufacturing an upset end through friction welding and the metallurgical and mechanical properties of the joint. The results showed a suitable welded joint with good top surface appearance and no defects. The samples have not fractured in fatigue tests, which indicate high fatigue life.","PeriodicalId":53327,"journal":{"name":"Tecnologia em Metalurgia Materiais e Mineracao","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70524106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.4322/2176-1523.20212147
Felipe Pinheiro Teixeira, Thaís Guedes Machado, Neilton Paixão de Jesus Junior, Simone Pereira Taguchi Borges, R. Ribeiro, Luiz Antônio Borges Júnior
The soil-cement brick has a low production cost, durability, no burning process, and is considered an ecological brick. The soil used presented particle size between 0.2-80μm, crystalline phases of quartz and kaolinite, liquidity and plasticity limities of 44% and 30% respectively. The soil powders:sand:CP-V ARI cement were mixed with 6:2:1 ratio, added water to acquire plasticity, formed by uniaxial pressing (2 tons), obtaining cylindrical test pieces of ϕ 50x100 mm, followed by curing in water for 7 days. They were submitted to the simple compression test, obtaining an average of 2.75 MPa. Two-hole soil-cement bricks, with the same composition, were pressed in a hydraulic press (6 tons), with dimensions of 250x126x69 mm, performed water absorption and simple compression tests, obtaining averages of 18.95% and 2.09 MPa, respectively. Both have mechanical resistance within the one estimated in NBR 8492, but smaller value for the brick, possibly due to the influence of the geometry and overlay effect.
{"title":"Propriedades tecnológicas do tijolo solo-cimento vazado de 2 furos","authors":"Felipe Pinheiro Teixeira, Thaís Guedes Machado, Neilton Paixão de Jesus Junior, Simone Pereira Taguchi Borges, R. Ribeiro, Luiz Antônio Borges Júnior","doi":"10.4322/2176-1523.20212147","DOIUrl":"https://doi.org/10.4322/2176-1523.20212147","url":null,"abstract":"The soil-cement brick has a low production cost, durability, no burning process, and is considered an ecological brick. The soil used presented particle size between 0.2-80μm, crystalline phases of quartz and kaolinite, liquidity and plasticity limities of 44% and 30% respectively. The soil powders:sand:CP-V ARI cement were mixed with 6:2:1 ratio, added water to acquire plasticity, formed by uniaxial pressing (2 tons), obtaining cylindrical test pieces of ϕ 50x100 mm, followed by curing in water for 7 days. They were submitted to the simple compression test, obtaining an average of 2.75 MPa. Two-hole soil-cement bricks, with the same composition, were pressed in a hydraulic press (6 tons), with dimensions of 250x126x69 mm, performed water absorption and simple compression tests, obtaining averages of 18.95% and 2.09 MPa, respectively. Both have mechanical resistance within the one estimated in NBR 8492, but smaller value for the brick, possibly due to the influence of the geometry and overlay effect.","PeriodicalId":53327,"journal":{"name":"Tecnologia em Metalurgia Materiais e Mineracao","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70524349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.4322/2176-1523.20212055
P. M. Fernandes, C. Oliveira
{"title":"Efeito do teor de zircônio e da deformação no envelhecimento de ligas Al-Zr","authors":"P. M. Fernandes, C. Oliveira","doi":"10.4322/2176-1523.20212055","DOIUrl":"https://doi.org/10.4322/2176-1523.20212055","url":null,"abstract":"","PeriodicalId":53327,"journal":{"name":"Tecnologia em Metalurgia Materiais e Mineracao","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70524493","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.4322/2176-1523.20212220
Paulo César Dias do Nascimento Júnior, Douglas Batista Mazzinghy, Carlos Esteves Teixeira, Fábio Paiva
{"title":"Uso de modelos paramétricos para estimativas de investimento aplicadas às etapas de britagem primária e secundária de minério de ferro","authors":"Paulo César Dias do Nascimento Júnior, Douglas Batista Mazzinghy, Carlos Esteves Teixeira, Fábio Paiva","doi":"10.4322/2176-1523.20212220","DOIUrl":"https://doi.org/10.4322/2176-1523.20212220","url":null,"abstract":"","PeriodicalId":53327,"journal":{"name":"Tecnologia em Metalurgia Materiais e Mineracao","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70524512","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.4322/2176-1523.20212316
Aylanna P. M. Araújo, Leandro Micheloti, C. S. Kiminami, Claudemiro Bolfari, V. Uhlenwinkel, P. Gargarella
This work aimed to produce powders of Al95Fe2Cr2Ti1 quasicrystalline phase former alloy using different atomizers, Hermiga (PH) and Spray forming/gas atomizer (PS), and investigate the powder characteristics as morphology, size distribution, flowability, microstructure, phase formation and thermal stability. The atomized powders were separated in different particles size ranges: <32μm, 32-45 μm and 45-75 μm. The characterization of powder microstructure and morphology for each range was carried out by X-ray diffraction, Optical and Scanning Electron Microscopy, Differential Scanning Calorimetry (DSC) and semi-quantitative composition analysis by Energy Dispersive Spectrometer (EDS). The flowability was measured by Carney funnel. The PH powder presented a bimodal particle size distribution and its particles displayed a constant circularity and aspect ratio with microstructure rich in quasicrystalline phase. The PS powder showed a unimodal particle size distribution and the circularity and aspect ratio decrease with increasing particles size. The PS powder flowability was 1.6 times better than PH powder.
{"title":"Morphological and microstructural characterization of Al95Fe2 Cr2 Ti1 powders produced by two different gas atomizers","authors":"Aylanna P. M. Araújo, Leandro Micheloti, C. S. Kiminami, Claudemiro Bolfari, V. Uhlenwinkel, P. Gargarella","doi":"10.4322/2176-1523.20212316","DOIUrl":"https://doi.org/10.4322/2176-1523.20212316","url":null,"abstract":"This work aimed to produce powders of Al95Fe2Cr2Ti1 quasicrystalline phase former alloy using different atomizers, Hermiga (PH) and Spray forming/gas atomizer (PS), and investigate the powder characteristics as morphology, size distribution, flowability, microstructure, phase formation and thermal stability. The atomized powders were separated in different particles size ranges: <32μm, 32-45 μm and 45-75 μm. The characterization of powder microstructure and morphology for each range was carried out by X-ray diffraction, Optical and Scanning Electron Microscopy, Differential Scanning Calorimetry (DSC) and semi-quantitative composition analysis by Energy Dispersive Spectrometer (EDS). The flowability was measured by Carney funnel. The PH powder presented a bimodal particle size distribution and its particles displayed a constant circularity and aspect ratio with microstructure rich in quasicrystalline phase. The PS powder showed a unimodal particle size distribution and the circularity and aspect ratio decrease with increasing particles size. The PS powder flowability was 1.6 times better than PH powder.","PeriodicalId":53327,"journal":{"name":"Tecnologia em Metalurgia Materiais e Mineracao","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70525061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.4322/2176-1523.20212459
E. Oliveira, E. Oliveira, C. Oliveira, A. G. Dal-Bó, M. Peterson
{"title":"Resíduos da indústria de canudos plásticos descartáveis: influência do tratamento alcalino sobre as propriedades de peças de concreto para pavimento intertravado","authors":"E. Oliveira, E. Oliveira, C. Oliveira, A. G. Dal-Bó, M. Peterson","doi":"10.4322/2176-1523.20212459","DOIUrl":"https://doi.org/10.4322/2176-1523.20212459","url":null,"abstract":"","PeriodicalId":53327,"journal":{"name":"Tecnologia em Metalurgia Materiais e Mineracao","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70525766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.4322/2176-1523.20212411
Mariana dos Reis Tagliari, P. Craidy, Derek Fonseca, M. F. Borges
{"title":"Stress corrosion cracking of carbon steels on CO2 /H2 O systems","authors":"Mariana dos Reis Tagliari, P. Craidy, Derek Fonseca, M. F. Borges","doi":"10.4322/2176-1523.20212411","DOIUrl":"https://doi.org/10.4322/2176-1523.20212411","url":null,"abstract":"","PeriodicalId":53327,"journal":{"name":"Tecnologia em Metalurgia Materiais e Mineracao","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70526049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.4322/2176-1523.20212425
Cássia Barbosa Gomes, Elaine Carballo Siqueira Correa, R. B. Soares, Ricardo Adriano Dorledo de Faria, Vanessa de Freitas Cunha Lins, W. Lopes
{"title":"Análise da influência das condições de envelhecimento na resistência mecânica e à corrosão do aço UNS S31803","authors":"Cássia Barbosa Gomes, Elaine Carballo Siqueira Correa, R. B. Soares, Ricardo Adriano Dorledo de Faria, Vanessa de Freitas Cunha Lins, W. Lopes","doi":"10.4322/2176-1523.20212425","DOIUrl":"https://doi.org/10.4322/2176-1523.20212425","url":null,"abstract":"","PeriodicalId":53327,"journal":{"name":"Tecnologia em Metalurgia Materiais e Mineracao","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70526060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：