DSpace Collection:http://hdl.handle.net/1843/26462024-03-29T00:19:29Z2024-03-29T00:19:29ZEstudo estatístico de determinação de capabilidade de produtividade estratificada em mix da linha de decapagem e laminador contínuo à frio acoplado e recozimento contínuo da planta de Ipatinga laminação de tiras a frio 02 (LTF02)http://hdl.handle.net/1843/335422020-05-25T20:51:22Z2016-07-07T00:00:00ZTitle: Estudo estatístico de determinação de capabilidade de produtividade estratificada em mix da linha de decapagem e laminador contínuo à frio acoplado e recozimento contínuo da planta de Ipatinga laminação de tiras a frio 02 (LTF02)
Abstract: The final product of analyzed process are the flat steel coils, and the productivity targets are determined taking into account the size and quality of the products generated in the integrated rolling mill (LTF2), cold rolling strip mill 2 of facilitie. Therefore, it is necessary statistically know whether the current processes have performance capable of meeting these goals. Currently the productivity indices measure the performance of manufacturing processes and indicate that they are working within certain specifications. The adopted procedure to determine productivity goals associates average of the last previous year as the starting value of the next cycle and the average of the three best results of the previous period as expected value at the end of the next cycle of production/budget. The results show that current production bands classified within annealing cycles, product quality and size were well defined and there is no evidence of bands with large variation in productivity which proves an error in determining these ranges. Finally, the statistics analysis of process performance (Pp) executed provide information that the expected average percentage results outside the specification limits were 1.92% for PLTCM and 1.65% for CAPL, which validates the method for preparing the current goals of productivity, resulting in achievable but challenging targets.
Type: Monografia (especialização)2016-07-07T00:00:00ZAnálise de Viabilidade Econômica da Substituição das Bases de Recozimento Convencional (HN) por Bases de Alta Convecção (HICON-H2®)http://hdl.handle.net/1843/ESBF-AQ2PG52019-11-14T19:29:06Z2016-12-09T00:00:00ZTitle: Análise de Viabilidade Econômica da Substituição das Bases de Recozimento Convencional (HN) por Bases de Alta Convecção (HICON-H2®)
Abstract: This monograph aims to identify the best form of economic feasibility analysis taking as focus the replacement of conventional annealing bases (HN) by high convection bases (HICON-H2®). The fundamental concepts explored in this work are due to the literature review of several authors that references on the subject of the application and verification of these concepts in a case study in one of the Manufacturing units of the Steel Mills of Minas Gerais S/A, in the city of Cubatão - São Paulo. Whereas the use and intensive application of information technology, pegged the cost area allow organizations have a further insight into the long-term short investment opportunity. The survey results show that for change in the operational process, the necessary investment in compared to the expected gain exceeds expectations, noticing be quite attractive seen in detail by the study.
Type: Monografias de Especialização2016-12-09T00:00:00ZCustos médios e marginais da Placa ComercialBelo Horizonte2016http://hdl.handle.net/1843/ESBF-ANZJJN2019-11-14T15:30:28Z2016-11-29T00:00:00ZTitle: Custos médios e marginais da Placa ComercialBelo Horizonte2016
Abstract: In recent years, the steel industry has suffered from a recent economic downturnand the increase in the importation of foreign of steel products. In a continued scenariowith a reduction of profit margins, it is crucial to understand the average and marginal slabcost to inform decision making in hiring business consultants.Usiminas already has a marginal cost model that covers ironmaking andsteelmaking, whose answer is the marginal cost of commercial slab. In this study, it wasevaluated the impacts of scrap steel consumption in metallic yield and in consumption ofother refrigerants materials (sinter and scale) in the converter in order to include them inthe model.A direct correlation between percentage of scrap and metallic yield in the Ipatingasteelworks was observed, which is in agreement with the literature, since the greater theproportion of scrap in the metallic burden of the converter (iron content greater than thehot metal), greater metallic yield. The correlation obtained in this case was 67.62%. Withthe inclusion of the impact in the model for scrap percentages of less than 14.0%, there wasnot much difference in the average cost and the marginal cost of slab with and withoutimpact on metallic yield. However, in the percentages up to 14.0% in metallic burden,there was a difference of 3 R$/ton and 2 R$/ton in the average cost and marginal cost ofthe slab, respectively, when compared with the costs without metallic yield impacting.Consumption of other obtained refrigerant materials (including sinter and scale)were not correlated with scrap consumption. In addition to others refrigerants materialsconsumption in the converter, other factors affect the thermal balance, for example,temperature and quality of hot metal, the addition of alloys, the use of limestone, amongothers.
Type: Monografias de Especialização2016-11-29T00:00:00ZOtimização do Plano de Compra, Estoque e Consumo de Carvõeshttp://hdl.handle.net/1843/ESBF-AL6HGT2019-11-14T16:56:50Z2017-02-17T00:00:00ZTitle: Otimização do Plano de Compra, Estoque e Consumo de Carvões
Abstract: One of the most important steps for a steel company's competitiveness is the definition of purchasing and consuming its raw materials. Among them are mineral coal and pet coke which correspond to about 30% of the final cost of the slab. At Usiminas, Ipatinga Plant, the annual potential fuel consumption is 2.3 million tons with a purchase budget roughly R$ 1.5 billion. The coal purchasing and consumption planning process at Usiminas is divided into two stages, in which the first defines an aggregate annual demand by a computational tool and the second defines a quarterly purchase of coal and coal consumption by mix independently. The fragmented planning between coal purchase and consumption, without considering all the assumptions in an integrated way, makes this process fragile and does not guarantee a decision making of the best possible scenario. In this work, was developed a mathematical model that integrates the purchase and consumption decisions of coal considering the assumptions of offers and stocks, operational restrictions and coke quality. The model was tested for artificial instances due to demand and coal supply and horizon of analysis sensitivities. The greatest performance was observed for scenarios with a horizon of 30 periods that obtained a mean MIPGAP of 2.37% and mean LINEAR GAP of 4.25% compared to 90 periods that obtained mean MIPGAP of 65.35% and mean LINEAR GAP of 93.68%. A variation of coal demand and offerings had no relevant impact on model performance. The model was applied to a real case study and provide a purchasing and consumption planning of coals that correspond to a potential economy of 5.8 MMR$ when compared to the one done in the analyzed quarter. The indication of the coal mix consumption is feasible and is in line with that already practiced by Usiminas historically. The developed tool shows great applicability as decision support of both purchase and consumption of coals, reducing the time spent on planning with reduction cost potential as it has global vision of the processes.
Type: Monografias de Especialização2017-02-17T00:00:00Z