This paper studied the effect of the austenite grain refinement on the tensile and impact properties of a cast Hadfield steel (12 % Mn, 1.2 %C and 0.65 % Si). The austenite grain refinement was obtained by hafnium inoculation. Microstructural characterization showed that the Hf-refined cast Hadfield steel featured a grain size of 600 µm, while the non-refined condition presented a grain size of 3000 µm. Mechanical test results indicated that the austenite grain refinement promoted an increase in the values of the yield stress (6%), the ultimate tensile strength (37%), the toughness (88%), the work-hardening coefficient (50%) and the Charpy absorbed energy (15%). Microscopic characterization of the fractured test-pieces indicated that the grain refinement increased the proportion of plastic deformation by the twinning mechanism and furthermore improved the values of the mechanical properties of the cast Hadfield steel considerably.

A literatura possui significativa quantidade de fatores críticos para o sucesso na gestão de projetos colaborativos, do tipo universidade-empresa. Esses fatores foram identificados por meio de estudos de casos múltiplos e levantamentos (surveys). Não há, portanto, estudos aprofundados verificando esses resultados. A pesquisa apresentada é do tipo observação participante em dois projetos, realizados entre um mesmo grupo de pesquisa e empresa. Avalia-se a percepção da equipe, a dos coordenadores dos projetos e do participante-observador (diário de campo), complementada pela análise de documentos e percepção dos stakeholders. O resultado mais significativo do caso é a indicação de que fatores relacionados ao contexto da parceria, tidos como críticos para o sucesso, agiram como condicionantes. Esse dado traz novas hipóteses sobre as listas de fator crítico e indica novas direções para a pesquisa.

There is a set of Critical Success Factors (CSF) for project management in the university-enterprise collaboration literature. A review indicated a need for new studies, applying more in-depth research methods. This paper analyzes two different projects, developed through the collaboration between a research group and a software enterprise. The analysis encompasses project coordinator and team member interviews and field diaries, which were complemented by analysis of documents. The results indicated that factors related to the management practices were more critical to the project success. The context of the university-enterprise partnership factors alone acted as qualifiers of the collaboration.

Os pesquisadores do IPT desenvolveram know-how para correlacionar os resultados laboratoriais de ensaios de desgaste de corpos moedores diretamente à indústria, por meio de constantes pesquisas e trabalhos realizados em parceria com o setor mínero-metalúrgico. Os ensaios padronizados em escala-piloto, com diferentes tipos de bolas de moinho, de ferros fundidos brancos de alto cromo e de aços temperados, nos quais avaliam-se as taxas e os micromecanismos de desgaste destas, fornecem uma correlação quantitativa direta com os resultados industriais. O presente trabalho teve como objetivo a caracterização dos corpos moedores para avaliação desse insumo adquirido de diferentes fornecedores para dar subsídio técnico às unidades de moagem industriais. As principais etapas foram: Determinação das curvas de polarização (avaliação do efeito de corrosão preferencial), Caracterização metalográfica (caracterização química e metalográfica das amostras de bolas) e Ensaio de desgaste (avaliação do desgaste dos corpos moedores em unidade-piloto contínua de moagem e classificação). Os resultados obtidos permitiram elaborar uma hierarquia de desempenho técnico.

The Division of Metallurgy of IPT has been working for some years in studies of grinding media wear. Tests have been conducted using phosphate and iron ores, as well as quartz sand, representing the range of abrasivity usually found in practical applications.The pilot plant scale testing program was carried out testing balls made of steel and of different types of high chromium white cast irons, evaluating the wear rates and analyzing the wear micromechanisms of these balls. In that work, the objective was the validation of the wear evaluation method, comparing the results obtained in an industrial ball mill, grinding phosphate ore with those obtained running continuously the pilot-scale laboratory mill. Quantitative correlations between the perfomance of the grinding media in the industrial and the laboratory ball mills were obtained. The present work had for objective the characterization of the grinding media for evaluation of balls acquired from different suppliers. The main stages were: Determination of the polarization curves (evaluation of the preferential corrosion's effect), Metallographic characterization (chemical and metallographic characterization of the balls samples) and Wear tests (to evaluate the wear of the grinding media in a continuous milling and classification pilot scale plant). The results obtained allowed to elaborate a ball wear rate ranking. The final result is a validated testing method available for the industry to foresee the wear of grinding media for each type of ore, making possible the selection of suppliers as well as the development of the best alloy for each case, aiming to lower costs in the grinding process.