Em virtude da demanda cada vez maior por materiais de alta qualidade, o avanço das tecnologias aplicadas na produção de aço vem acompanhado pelo avanço na fabricação de revestimentos refratários de alto desempenho e que atendam às solicitações de processo sem interferir nas propriedades finais do material produzido. Os refratários de magnésia-carbono são atualmente os materiais mais utilizados em equipamentos siderúrgicos tanto de transporte como de refino do aço, sendo de extrema importância o conhecimento da qualidade das matérias primas utilizadas na confecção destes materiais. O presente trabalho tem como objetivo estudar como ocorre a corrosão da magnésia (eletrofundida e sinterizada) por escória de aciaria LD em ensaios de corrosão estáticos (cup-test) porém com algumas modificações ao ensaio convencional, chamado assim de cup-test modificado. A magnésia foi caracterizada por ensaios de caracterização química (fluorescência de raios X), mineralógica (difratometria de raios X) e microestrutural (microscopia eletrônica de varredura com análise da energia dispersiva de raios X). A análise química mostrou que as principais impurezas do material eram de cálcia (CaO) e sílica (SiO2) e a análise microestrutural mostrou que estas impurezas se concentram nos contornos de grão dos agregados eletrofundidos e dispersos por todo o material nos sinterizados, sendo encontrado apenas periclásio como fase mineralógica. Os maiores tamanhos médios de grãos foram encontrados na amostra ME3 e os menores na ME1. A escória utilizada é proveniente do conversor (BOF), com alta concentração de FeO. As análises após os ensaios de cup-test modificado mostraram que o ataque aos agregados se deu principalmente pela infiltração de fases contendo ferro pelos contornos de grão, arrastando-os para o banho e dissolvendo o MgO na escória. Dentre os eletrofundidos, podemos estimar a ordem de desempenho da seguinte maneira: ME3>ME2>ME1. Considerando os sinterizados, a ordem de desempenho é tal que: MS3>MS1>MS2. / High quality materials are increasingly desired by consumers, and advances in technologies of steelmaking processes are closely linked to manufacturing suitable high performance refractories which do not interfere in the final properties of materials produced. Magnesia-carbon refractories are widely used in several steelmaking plants, both for transportation and refining processes which makes the knowledge of the quality of raw materials is essential for manufacturing high quality refractories. In this work, the approach is the study of how the corrosion behavior of magnesia aggregates (sinterized and electrofused) by LD steelmaking slag occurs using a modified crucible testing. The magnesia aggregates were characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD) and scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS). The XRF analysis shows that the main impurities of magnesia grains is CaO and SiO2 and the SEM analysis showed their impurities are concentrate on grain boundary in electrofused magnesia, while it is found throughout the sinterized magnesia aggregates. The major phase found both magnesia aggregates is periclase. The largest grain sizes were found in ME3 samples, while the smaller sizes in ME1. The slag used comes from converter (BOF) and has high concentration of FeO. The corrosion tests showed that the attack on magnesia aggregates occurred, mainly by the infiltrating of iron compounds in the grain boundary, dragging the grains to the bath and dissolving them into slag. Among the electrofused, the performance could be estimated in ME3>ME2>ME1. The performance for sinterized would be as follows MS3>MS1>MS2.

The sheet metal forming process basically involves the shaping of sheet metal of various thickness and material properties into the desired contours. This metal forming process has been extensively used by the automotive industry to manufacture both car panels and parts. Over the years numerous investigations have been conducted on various aspects of the manufacturing process with varied success. In recent years the requirements on the sheet metal forming industry have headed towards improved stability in the forming process while lowering environmental burdens. Therefore the overall aim of this research was to identify a technique for developing lubricant formulations that are insensitive to the sheet metal forming process. Due to the expense of running experiments on production presses and to improve time efficiency of the process the evaluation procedure was required to be performed in a laboratory. Preliminary investigations in the friction/lubricant system identified several laboratory tests capable of measuring lubricant performance and their interaction with process variables. However, little was found on the correlation between laboratory tests and production performance of lubricants. Therefore the focus of the research switched to identifying links between the performance of lubricants in a production environment and laboratory tests. To reduce the influence of external parameters all significant process variables were identified and included in the correlation study to ensure that lubricant formulations could be desensitised to all significant variables. The significant process variables were found to be sensitive to die position, for instance: contact pressure, blank coating of the strips and surface roughness of the dies were found significant for the flat areas of the die while no variables affected friction when polished drawbeads were used. The next phase was to identify the interaction between the significant variables and the main lubricant ingredient groups. Only the fatty material ingredient group (responsible for the formation of boundary lubricant regimes) was found to significantly influence friction with no interaction between the ingredient groups. The influence of varying this ingredient group was then investigated in a production part and compared to laboratory results. The correlation between production performance and laboratory tests was found to be test dependant. With both the Flat Face Friction test and the Drawbead Simulator unaffected by changes in the lubricant formulation, while the Flat Bottom Cup test showing similar results as the production trial. It is believed that the lack of correlation between the friction tests and the production performance of the lubricant is due to the absence of bulk plastic deformation of the strip. For this reason the Ohio State University (OSU) friction test was incorporated in the lubricant evaluation procedure along with a Flat Bottom Cup test. Finally, it is strongly believed that if the lubricant evaluation procedure highlighted in this research is followed then lubricant formulations can be developed confidently in the laboratory.

Many pieces of fine art are made of wood that has been treated with coatings. Since wood is a very hygroscopic material, the moisture content strongly influences the deformation of wooden parts. Coatings often act as moisture barriers. Therefore, the moisture permeability of coatings must be considered for the evaluation of the structural behaviour. The mechanical properties are also relevant to evaluate the deformation of thin artwork like panel paintings as well as the damage of paintings and varnishes. Therefore, the mechanical properties and the permeability of selected coatings used for cultural wooden artwork are investigated and presented in the article at hand. In this study, coatings of three artworks are investigated: a Lusatian cupboard from the eighteenth century, an altarpiece by L. Cranach the Elder and a Russian icon from 1912. The coatings considered are white ground, colours, varnishes, glue and textile reinforced sizing. Mechanical tests are conducted to evaluate the stiffness and tensile strength of the Russian icon’s coating. Cup tests are made to identify the moisture permeability of the coatings. This test was conducted for single coatings as well as for coating systems consisting of different coatings to investigate both the moisture barrier of single coatings and the interaction of coatings. Exponential functions for the relative humidity-dependent permeability are fitted based on the experimental data. The results allow the quantification of permeability for all investigated coatings—from white ground with a high permeability to beeswax with a low permeability—and the magnitude of moisture dependency of the coating’s permeability. Furthermore, it is shown that the simple addition of the water vapour resistance of single coatings underrates the resistance of a total coating system. By the mechanical tests, the strength, ultimate strain and Young’s modulus are obtained. The permeability and the mechanical parameters are required as input for numerical simulations of the structural behaviour of coated wooden artwork. These results are a good step forward to assess the risk of damage of coated wooden artwork.