?rea de concentra??o: Manejo florestal. / Data de aprova??o retirada da vers?o impressa da disserta??o. / Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2018-02-16T21:29:35Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) marcelino_breguez_goncalves_sobrinho.pdf: 1141104 bytes, checksum: ccb26c2686949cf99a1c9c1fcfca38e6 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2018-03-09T19:36:14Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) marcelino_breguez_goncalves_sobrinho.pdf: 1141104 bytes, checksum: ccb26c2686949cf99a1c9c1fcfca38e6 (MD5) / Made available in DSpace on 2018-03-09T19:36:14Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) marcelino_breguez_goncalves_sobrinho.pdf: 1141104 bytes, checksum: ccb26c2686949cf99a1c9c1fcfca38e6 (MD5) Previous issue date: 2016 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (Capes) / O Brasil ? o maior produtor mundial de carv?o vegetal, sendo que os principais consumidores s?o os setores de ferro-gusa, a?o e ferro-ligas e, em menor escala, o com?rcio e o consumidor residencial. Um carv?o vegetal de boa qualidade para a produ??o de ferro-ligas deve apresentar densidade a granel acima de 250 Kg.m-3, carbono fixo em torno de 75%, teor de cinzas abaixo de 1%, aproximadamente 25% de materiais vol?teis, teor de umidade abaixo de 6%, baixo teor de finos e com boa resist?ncia mec?nica. Estas propriedades f?sicas, qu?micas e mec?nicas diminuem o custo e aumenta a qualidade das ligas de ferro. Objetivou-se com essa pesquisa avaliar as propriedades f?sicas do carv?o vegetal de Eucalyptus sp. e, a influ?ncia da qualidade deste na produ??o de ferro ligas. Foram analisadas amostras desta mat?ria prima em cen?rios diferentes para avaliar sua qualidade. Um cen?rio o carv?o vegetal era transportado em estrada de terra e no outro em estrada pavimentada. A pesquisa foi realizada no laborat?rio de qualidade de carv?o vegetal em uma empresa do litoral norte baiano. Determinou-se a densidade a granel (Kg.m-3), o tamanho m?dio das part?culas (mm) e o teor de finos (%) do carv?o vegetal. Os testes e as coletas foram executados de acordo com as respectivas normas da ABNT. As avalia??es mostraram que a qualidade do carv?o vegetal quanto ?s suas propriedades f?sicas s?o alteradas pelo manuseio e transporte do produto at? a f?brica na metalurgia. Em rela??o ao transporte da mat?ria prima em estrada de terra e asfalto n?o ocorreu diferen?a impactante de uma para outra. Logo, torna-se interessante padronizar o manuseio e a carboniza??o para que o carv?o vegetal sofra menos quedas pois, a gera??o de finos foi bastante representativa. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Ci?ncia Florestal, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2016. / Brazil is the largest producer of wood charcoal, and the main consumers are the sectors iron industries, steel and ferroalloys and, to a lesser extent, trade and residential consumers. The quality of charcoal depends directly on the physical, chemical and anatomical wood that originated it. A good quality wood charcoal for the production of ferroalloys must provide bulk density above 250 kg.m-3, fixed carbon about 75%, ash content below 1%, approximately 25% volatiles, moisture content below 6%, low fines content and good mechanical strength. These physical, chemical and mechanical properties decrease the cost and increase the quality of ferroalloys. The Brazilian segment of ferroalloys is fairly diverse and occupies a prominent position on the world stage. Among the factors that led to this condition relates to the availability of raw materials. We aimed to evaluate the quality of the wood charcoal used in the production of ferroalloys. Wood charcoal samples were evaluated in different canaries to assess their quality. The survey was conducted in wood charcoal quality laboratory in a company of Bahia north coast. It was determined bulk density (kg.m-3), the average particle size (mm) and a fines content (%). The evaluations showed that the quality of the physical properties of wood charcoal are changed by handling and transportation of the product to the plant in metallurgy. The transport on dirt road and asphalt was not an impressive point. Therefore, the greater the resistance charcoal, less impact its physical properties will suffer.

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Nitrogen-alloyed tool steel is made at Uddeholms AB by adding high-nitrogen ferroalloy after vacuum degassing where introduced impurities are hard to remove. In this thesis two types of high-nitrogen ferrochromium are compared, a solid version and a powder cored wire. They are examined in crossection and 16 samples from four charges are examined with Pulse Distribution Analysis as well as systematic microscopy of polished cross sections. The PDA results missed smaller spinel inclusions shown in previous research to be detrimental. The wire form shows promise but more charges need to be evaluated before a conclusion is drawn. / Kvävelegerat verktygsstål tillverkas hos Uddeholms AB genom tillsats av kväverika ferrolegeringar efter vakumavgasning, och orenheter som introduceras i detta steg är svåra att avskilja. I den har uppsatsen jämförs två typer av kväverikt ferrokrom varav en i form av stycken och en i form av tråd med pulverkärna. De undersöks i tvärsnitt och totalt 16 prov från fyra charger undersöks med PDA (pulsfördelningsanalys) och systematisk mikroskopering i tvärsnitt. Resultaten från PDA missade mindre inneslutningar av spinell vilka tidigare har visat sig problematiska. Trådformen verkar lovande men fler charger behöver undersökas för att kunna dra en definitiv slutsats.