Modelamento matemático do refino do aço inoxidável em conversores AOD-L

• Ano de defesa: 2006
• Autor(a) principal: Humberto Marin
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Descarburação; AOD; Aços inoxidáveis; Modelos matemáticos; Engenharia metalúrgica; Aço inoxidavel; Metalurgia extrativa
• Link de acesso: http://hdl.handle.net/1843/BUOS-8DHFBC

In the present work was presented a study about the development and the application of a multiphase and multicomponent mathematical model for the decarburisation of stainless steels. The developed model takes into account three possible interfaces of reaction (metal-gas, metal-oxide and oxide-gas) and considers the main components involved in the process (C, Cr, Fe, Ni, Mn, Si, Al, O). To model the process it was assumed that the oxygen injected by the bottom in the converter reacts with the metal in the region of the tuyeres, forming metallic oxides that rise with the gas bubbles. During the rising of the bubbles, the oxides are dragged and reduced, forming CO and CO2 due to the reaction with the carbon dissolved in the bath. This causes a carbon flow towards the gaseous phase (bubbles) and, consequently, decarburisation. Themodel was adjusted to the Acesita S.A. 80 tonnes AOD-L converter process conditions. The converter works with charge from an electric arc furnace and dephosforized hot metal. The simulation results showed that the model reproduces well the main process variations (bath temperature, bath chemical composition and oxygen dilution by inertgas), corresponding to the operational practice and bibliographic reports. The results of the simulations were compared to industrial data, of austenitic ACE P304A steel grade and of ferritic ACE P430A steel grade heats, giving a good prevision of carbon content and temperature as function of the process time