Orientador: Luiz Antonio Rossi / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-17T20:55:25Z (GMT). No. of bitstreams: 1 Barros_RegianeSilvade_M.pdf: 4809578 bytes, checksum: 3c66513eb6c044f7320b1bc7da1bcdb9 (MD5) Previous issue date: 2011 / Resumo: Durante boa parte de 2001 e o início de 2002, o Brasil enfrentou a crise do abastecimento de energia elétrica. Dada a necessidade de assegurar o abastecimento de energia, torna-se vantajoso investir em eficiência energética. Com tais medidas são postergados investimentos no setor elétrico, principalmente, sob a ótica da oferta, quando, a construção de novas usinas é minimizada e, conseqüentemente, os investimentos nos sistemas de transmissão. Especificamente no setor industrial, a eficiência energética tem importância fundamental, uma vez que, o setor é responsável por boa parte da demanda de energia do País, portanto, estudos sobre o consumo de eletricidade nesse segmento são importantes. Sendo assim, objetivando alcançar melhores resultados, nesse setor, quanto ao uso da energia elétrica, ressalta-se a importância da caracterização de seu uso. E em consonância, de uma análise mais detalhada das principais grandezas relativas à energia elétrica nas instalações industriais, pode-se apontar melhores práticas que levem ao uso eficiente desse insumo. Neste trabalho, especificamente, foram analisadas três empresas do segmento metalúrgico no Estado de São Paulo, quanto ao perfil do uso da energia elétrica. Analisaram-se as principais variáveis de energia elétrica (fator de carga, fator de potência, consumo de energia e demanda), bem como os indicadores de consumo específico e intensidade elétrica. Por meio das análises, notou-se que cabem medidas de uso racional de energia elétrica nessas empresas quanto à melhoria do fator de carga e modulação de carga, que, por sua vez, podem levar à melhores indicadores de consumo específico e intensidade energética / Abstract: During good part of 2001 and the beginning of 2002, Brazil faced the supplying crisis of electric energy. Given the necessity to assure the energy supply, it becomes advantageous to invest in energy efficiency. With such measures, investments in the electric sector are postponed, mainly under the optics of offer, when, the construction of new plants are minimized and, consequently the investments in transmission systems. Specifically in the industrial sector, the energy efficiency is very important, once, this sector is responsible for good part of energy demand in the country; therefore, studies related to the electric energy consumption in this sector are important. Being thus, objectifying itself to reach better results, in this segment, regarding the use of electric energy, the characterization of its use is necessary. A more detailed analysis of the main quantities related to electric energy at industrial plants, may point out the best practices that lead to a more efficient use of this input. In this work, specifically, three metallurgical companies in the State of Sao Paulo were evaluated, regarding the profile of the use of electric power. The main parameters of electric energy were examined (load factor, power factor, energy consumption and demand), as well as, the indicators of specific consumption and energy intensity. Based on this analysis it was noted that some measures of rational use of energy can be applied in these companies, such as, the improvement of load factor and load modulation that can lead best pointers of specific consumption and energy intensity / Mestrado / Engenharia Mecanica / Mestre em Planejamento de Sistemas Energéticos

Os Aluminetos de Ferro tem, dentre muitas características predominantes, excelente resistência à corrosão a altas temperaturas devido à formação de uma camada protetora de alumina que favorece a sua aplicação em ambientes agressivos. Este trabalho tem por objetivo estudar a produção de ligas a partir de matéria-prima reciclada e a cinética de oxidação em alta temperatura de 800 graus Celsius a 1100 graus Celsius em forno mufla sem atmosfera protetora com tempo de permanência no forno de 10, 50, 100 e 200h. As ligas estudadas se baseiam na composição básica Fe30Al6Cr (os números representam a fração molar dos componentes). Duas ligas, nomeadas (A) e (B), foram obtidas seguindo a mesma rota de processamento, porém, diferenciando os cadinhos de fundição o que resultou em concentrações de carbono diferentes e conseqüente diferença na fração volumétrica de carbonetos. As ligas foram analisadas através de difração de Raio X para determinação das fases presentes e microscopia eletrônica de varredura para caracterização microestrutural. Foram também, submetidas ao ensaio de solubilização por 10 horas a uma temperatura de 1200 graus Celsius e precipitação a 800 graus Celsius por 10 min para determinação da evolução microestrutural. O resultados das análises de microdureza Vickers no material em estados bruto de fusão e tratado termicamente serviram para caracterizar os carbonetos presentes, bem como a resistência intrínseca da matriz. Os resultados do ensaio de oxidação realizado em 16 amostras de cada liga são apresentados sob forma de curvas de ganho de massa por unidade de área, (deltam/S), versus tempo de oxidação, (t). A avaliação feita das curvas dos gráficos não foi suficiente para determinar à cinética de formação de óxidos. / Iron aluminides have, among many outstanding characteristics, excellent resistance to high temperature oxidation due to the formation of a protective alumina layer which favors its use in harsh environments. This work aims at producing iron aluminides-based alloy using only recycled raw material and characterizing the results of studies of oxidation kinetic at high temperatures of 800 Celsius to 1100 Celsius in muffle furnace without protective atmosphere with residence time in oven 10, 50, 100 and 200h. The investigated alloy are based on the nominal composition Fe30Al6Cr (The numbers refer to the molar fraction of alloys elementes). Two alloys, namely (A) and (B), were obtained following the same processing route using, however, different crucibles which resulted in different carbon concentrations and consequently in different carbide volume fractions. The alloys were analyzed by X-ray diffraction to determine the phases and scanning electron microscopy for microstructural characterization. Sample taken from both alloys were also subjected to solubilization for 10 hours at 1200 Celsius and precipitation at 800 Celsius for 10 min to determine the microstructural evolution. The analytical results of Vickers microhardness of the material both in the as cast state as well as in the heat treated states were used to characterize the carbides and matrix mechanical properties. Oxidation results carried out in 16 samples of each alloy are presented in the form of mass gain per unit area (deltam / S) versus oxidation time (t) curves. The evaluation of the graphics curves used to observe the linear behavior was not enough to determine the oxidation kinetics law.

Este trabalho consiste em uma pesquisa sobre aços inoxidáveis ferríticomartensíticos de ativação reduzida (RAFM): EUROFER (9Cr-1W) e ODS-EUROFER (9Cr-1W-0,3Y2O3), envolvendo o encruamento e a recristalização destas duas ligas com o objetivo de estudar a influência de uma dispersão de partículas nanométricas na recristalização de aços inoxidáveis. O conceito de materiais de ativação reduzida é discutido e é apresentada a aplicação destes aços tanto na estrutura de diversor do ITER quanto na primeira parede no módulo de câmara fértil do reator DEMO. As placas, no estado revenido, foram laminadas a frio em um laminador de pequeno porte. As curvas de encruamento de ambos os materiais mostram um comportamento quase linear. Os tratamentos isócronos de uma hora, entre 300 e 750 °C, resultaram curvas de amolecimento que indicam uma forte resistência à recristalização da liga ODS-EUROFER, em concordância com os modelos teóricos. A liga EUROFER-97 apresentou recristalização muito similar a liga comercial 430, mas com maior dureza inicial, devido a maior quantidade de elementos intersticiais. / This work studies reduced activation ferritic-martensitic (RAFM) stainless steels: EUROFER (9Cr-1W) and ODS-EUROFER (9Cr-1W-0,3Y2O3), and their work hardening and recrystallization behaviour to better understand the influence of a dispersion of nanometric particles on the recrystallization process of stainless steels. The concept of reduced activation materials is discussed and the application of these steel alloys, such as in the divertor structure of ITER (International Thermonuclear Experimental Reactor) and as in the DEMO reactor breeding blanket first wall is shown. The plates, in the as-tempered condition, were cold rolled in a laboratory rolling mill. The work hardness curves of both materials presented an approximately linear behavior with strain increase. One hour isochronal treatments, in the temperature range from 300 to 750 °C, resulted in softening curves that indicated a strong resistance to recrystallization of the alloy ODS-EUROFER, supporting the theorical models. The EUROFER-97 recrystallization showed a similar behaviour to the commercial 430 alloy, however with higher initial hardness, due to the larger amount of interstitial elements.

O principal objetivo desta pesquisa é fazer um estudo e uma discussão comparativa sobre o modo como dois importantes personagens sociais são retratados pela cinematografia brasileira em um conjunto delimitado de filmes: o Metalúrgico e o Motoboy. Por meio de uma análise estética e narrativa, investiga-se como cineastas lançaram o olhar sobre a realidade contemporânea e construíram um imaginário audiovisual dessas categorias profissionais. Com base em autores como Bernardet (2003), Tomizaki (2007), Eisenstein (1990), Pudovkin (1961), Silva (2011), Nichols (1991) entre outros que discutem o tema, analisam-se seis documentários brasileiros que retratam a vida e saga dos protagonistas deste estudo. Recorre-se também, para cotejar a produção nacional em relação ao que cineastas estrangeiros têm produzido sobre o tema, a filmes correlatos, como A Classe operária vai ao paraíso (1971), Sem destino (1969) e outros. A análise inclui a discussão de aspectos técnicos que vão do posicionamento de câmeras, tomadas de cena até a montagem e trilha sonora. Entre as conclusões, pode-se observar que, enquanto os metalúrgicos construíram uma identidade ante a sociedade, os motoboys continuam a ser uma incógnita perturbadora, personagens que vêm sabe-se lá de onde, vivendo um eterno e cruel presente, sem perspectivas de futuro, trabalhando numa profissão perigosa e de certa forma desprestigiados pela população. O processo de pesquisa da tese são o fundamento e a orientação para um novo documentário a ser finalizado e que vem sendo pensado como uma reflexão cinematográfica sobre os avanços e reveses, expectativas e desilusões do projeto de modernização industrial e urbana da sociedade brasileira. / The main objective of this research is to make a study and a comparative discussion on how two important social characters are portrayed by the Brazilian cinema in a set, delimited, of movies: the Metallurgical and the Motoboy. Through an aesthetic and narrative analysis, investigating as filmmakers cast their eyes on contemporary reality and built a visual imagery of these professional categories. Based on authors like Bernardet (2003), Tomizaki (2007), Eisenstein (1990), Pudovkin (1961), Silva (2011), Nichols (1991) among others discussing the issue, we analyze six Brazilian documentaries depicting the life and saga of the protagonists of this study. It also refers to collate domestic production in relation to foreign filmmakers that have produced on the subject, about related films such as The Working class goes to paradise (1971), Easy rider (1969) and other examples. The analysis includes a discussion of technical issues ranging from cameras placement, taken to the assembly and soundtrack. Among findings, it can be observed that, while the metallurgical built an identity to society, couriers remain a disturbing unknown, characters who come who knows where, living in an eternal and cruel fate, without future prospects, working in a dangerous profession and somewhat discredited by the population. The research process of the thesis are the basis and the guidance for a new documentary to be finalized and intended as a cine reflection on the progress and setbacks on the expectations and disappointments of industrial and urban modernization project of Brazilian society.

The power of thermodynamics in the calculation of complex chemical and metallurgical equilibria of importance to industry has, over the last 15 years, been considerably enhanced by the availability of computers. It has resulted in the storage of data in databanks, the use of physical but complex models to represent thermodynamic data, the vast effort spent in the generation of critically assessed data and the development of sophisticated software for their application in equilibrium calculations. This thesis is concerned with the generation and application of metallurgical thermodynamic data in which the computer plays a central and essential role. A very wide range of topics have been covered from the generation of data by experiment and critical assessment through to the application of these data in calculations of importance to industry. Particular emphasis is placed on the need for reliable models and expressions which can represent the molar Gibbs energy as a function of temperature and composition. In addition a new computer program is described and used for the automatic calculation of phase diagrams for binary systems. Measurements of the enthalpies of formation of alloys in the Fe-Ti system are reported. All data for this system have been critically assessed to provide a dataset consistent with the published phase diagram. Critically assessed data for a number of binary alloy systems have been combined in order to perform quantitative calculations in two types of steel system. Firstly data for the Cr-Fe-Ni-Si-Ti system have been used to provide information about the long term stability of alloys used in fast breeder nuclear reactors. Secondly very complex calculations involving nine elements have been made to predict the distribution of carbon and various impurities between competing phases in low alloy steels on the addition of Mischmetall. Finally a new model is developed to represent the thermodynamic data for sulphide liquids and is used in the critical assessment and calculation of data for the Cu-Fe-Ni-S system. The phase diagram and thermodynamic data calculated from the assessed data are in excellent agreement with those observed experimentally. The work reported in this thesis, whilst successful, has also indicated areas which will benefit from further study particularly the development of reliable data and models for pure elements, ordered solid phases and liquid phases for high affinity systems.

Diploma thesis focuses on standardization of selected commodity, purchased for manufacturing using in the company. For this commodity is realized analysis, on it’s bases will be proposed more effective purchasing model. The finaly result of this diploma thesis should be achieve savings connected with purchase.

Notre travail est consacré à l’étude des matériaux carbonés utilisés comme réducteurs pour la production des alliages de manganèse dans le four électrique à arc immergé. Le choix du réducteur est important pour l’optimisation du procédé métallurgique et sa réactivité au CO2 est le paramètre le plus important utilisé par les producteurs de ferroalliages pour évaluer sa qualité. Les objectifs de notre travail sont : ? d’établir les critères de sélection du coke métallurgique ou réducteur de remplacement, utilisés pour la production des alliages de manganèse dans le four électrique, en utilisant la réactivité au CO2 comme le principal paramètre pour évaluer sa qualité ; ? d’un point de vue plus fondamental, apporter une meilleure compréhension des réactions du carbone dans le réacteur industriel. Dans l’optique d’une modélisation globale du four électrique, notre travail fournit des paramètres cinétiques d’une des réactions les plus importantes du procédé : la réaction de Boudouard. L’étude de la réductibilité des oxydes de manganèse pourrait donc être une nouvelle étape vers la construction d’un modèle global du réacteur industriel. Un troisième volet d’expériences utile à la modélisation serait l’étude de l’influence de la nature et du calibre du réducteur sur la résistivité électrique de la charge. / The main aims of our work have been to establish criteria useful for reductant selection, using coke reactivity to CO2 as the main parameter for reductant quality assessment and, from a fundamental point of view, to develop a better understanding of carbon reactions inside the industrial reactor. Therefore, Boudouard reaction has been studied on three increasing scales: intrinsic chemical reaction, coke lump, and coke bed scales. Several different types of carbonaceous materials have been studied. They represent the variety of reductants commonly used in the production of manganese ferroalloys in the electric furnace. It has been shown that this extended range of reductants introduces large differences between their characteristics, mainly between their reactivity to CO2. Regarding the coke lump gasification kinetics, the Langmuir-Hinshelwood model has been used to represent the intrinsic rate of the Boudouard reaction. A good correlation has been found between the initial gasification rates of the coke beds and the single coke lumps. The difference between these rates increases with increasing reductant reactivity. It is possible to determine coke gasification regime inside the industrial electric arc furnace using single particle and coke bed gasification models. The overall rate at which coke reacts with CO2 inside the industrial reactor is probably limited by the intrinsic chemical reaction. Therefore, a reactivity index, based on the initial gasification rate of the reductant, measured in the chemical-kinetics controlled regime, seems to be adapted to the reductant quality assessment. An additional technique could be the microtextural analysis.

Theses in the theoretical part discusses generally the appropriate methods and practices of storing of material. It deals with the question, what are the benefits of warehousing, and what are classic and modern methods of storing. In the practical part it describes the warehousing of concrete company and outlined the possibility of improving the services in the field of logistics.

The thesis discusses the impact of nostrification action on particular companies mining and metallurgical industries in inter-war Czechoslovakia. The aim of the analysis is to test the hypothesis of nostrification as "clientelist changing of the guard" on the particular case of the three largest mining and metallurgical enterprises in First Republic of Czechoslovakia. First is discussed the state of the mining and metallurgical industry as a whole. Then there is brief discuss about nostrification. Finally, there are particular companies analyzed. Final opinion to the defined hypothesis is discussed, through the answer on a defined set of questions

M.Sc. / This study focuses on the mineralogical variability of the A1, A5 and UE1A Elsburg reefs, obtained at Rand Uranium’s underground mining areas. A total of 133 reef samples, consisting of the Elsburg UE1A, A1 and A5-reefs have been obtained from Cooke 2 and 3 (two of the three Rand Uranium Mines) using the conventional chip sampling method. One of the challenges faced by Rand Uranium Gold Mines in the Cooke section area is the difficulty in differentiating between the various reef types by means of their macroscopic characteristics (colour, pebble types/sizes/shapes, sorting, matrix type, visible sulphide mineralization etc.). This difficulty led to this study which is aimed at utilizing mineral liberation analyzer (MLA)-based automated mineralogy to distinguish between the various reefs and to assess the mineralogical variation within the A1, A5 and UE1A-reefs. The mineralization in this area is hosted by the upper Central Rand Group of the Witwatersrand Supergroup. The main orebodies that are exploited at the mines occur within the Gemsbokfontein Member of the Elsburg Formation. These orebodies have been deformed into an east-west trending anticline at Cooke 3. The present study also attempts to prove or disprove the equivalence of the UE1A-reef on the western limb of the anticline to the A1 or A5-reefs on the eastern limb of the anticline on the basis of mineralogy. Representative splits of the samples were subjected to mineralogical abundance quantification as possible through quantitative MLA-based modal abundance protocols such as XMOD. A standard file on the various mineralogical phases encountered, was created on the 600F MLA and complemented by quantitative XRD (X-ray diffraction) data. Mineral abundances were quantified by MLA, based on integrated backscatter electron (BSE) images and energy dispersive spectrometry (EDS) analyses. Thirty one minerals have been detected using the MLA and they include phases such as quartz, pyrophyllite, chlorite, brannerite, gold, monazite and pyrite as well as minor unknown minerals. Only a few of the minerals are relatively more abundant within the reefs while the majority occurs in very low abundance. Albite, chlorite, muscovite, pyrite, pyrophyllite, quartz, uraninite and zircon are relatively more abundant than the rest of the minerals.