Metodologia numérico-experimental para determinação da qualidade de aços obtidos por lingotamento contínuo

• Autor(a) principal: Anjos, Tarquínio Plynio Durães dos
• Data de Publicação: 2013
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Ceará (UFC)
• Texto Completo: http://www.repositorio.ufc.br/handle/riufc/54510
• topic: Lingotamento contínuo; Aço; Simulação numérica; Solidificação; Transferência de calor

The continuous casting process has been widely used in steel production. It is characterized by the solidification of liquid steel in several forms that will be used later for mechanical forming processes. Therefore, the conditions under which the heat transfer takes place in several stages of this cooling process will have a large effect on the product quality and the process productivity. The main goal of this work is the development of a mathematical model capable of describing the solidification behavior during the several stages of the continuous casting process. Thermocouples are inserted into the outer walls of a mold of 100x100 mm square section in order to evaluate the temperature of the walls’ mold. Hence, a numerical procedure is developed to evaluate the heat transfer coefficients at the metal/mold interface. Therefore, it will be possible to verify the influence of several parameters of continuous casting process on the behavior of the heat transfer coefficient at the metal/mold interface. Based on this study, equations to determine the overall heat transfer coefficient at the metal/mold interfaces as a function of process variables, such as steel chemical composition and casting speed, are suggested. Measurements of the lingot surface temperature are also obtained using an optical pyrometer along with the secondary and the radiation/natural convection cooling zones. Therefore, it was possible to obtain the heat transfer coefficients in all the three zones. Using the obtained coefficients, it was possible to simulate the solidification process in continuous casting machine thorough the analysis of the temperature profile and solidified shell thickness for the investigated machine. Based on the results and standard quality criteria from the literature, it was possible to identify operational conditions capable of generating possible cracks and operational problems to the continuous casting process. Therefore, based on the simulated results, operational and structural parameters to improve the Continuous Casting process are suggested.