Mathematical modeling of inclusion removal from steel during ladle teeming during inert gas injection

• Autor(a) principal: Alexandre Dolabella Resende
• Data de Publicação: 2019
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Institucional da UFMG
• Texto Completo: http://hdl.handle.net/1843/30345
• topic: Computational Fluid Dynamics; Steel Cleanliness; Secondary Metallurgy; Inclusions; Inert Gas Injection; Engenharia metalúrgica; Metalurgia extrativa; Aço - Inclusões; Modelos matemáticos

Steel products are present in various applications in the contemporary world, in which many of them require control of the amount of impurities. With technological advancement and globalized competition, such requirements are becoming stricter. In this context, continuous improvement of the processes is necessary. However, the high temperatures and operational risks make it difficult for studies to be performed directly on the industrial equipment. Therefore, experimental and mathematical models are frequently used with the goal of analyzing physical phenomena involved in steelmaking and to predict the performance of alternative proposals in the final product quality. In the present work, a mathematical model was developed with the objective of studying non-metallic inclusion removal from the molten steel during ladle teeming. Different mathematical modeling approaches have been tested in order to obtain the model which would better represent the phenomenon to be studied, what has been verified through the comparison with experimental results obtained in a physical model of an industrial ladle. It has been verified that the mathematical model in which the free surface motion was represented has shown results more consistent with the experiments. Moreover, it has been observed that the inclusion removal results were very sensitive to the inclusion removal criterion adopted, so that a custom criterion has been adopted. Through the developed model, the effects of the gas flow rate and time duration of the purging treatment have been studied. It has been observed that, in the ranges of values studied, both parameters have shown a positive correlation with the inclusion removal from steel in the ladle, with greater relevance for the time duration of the purging treatment.