Análise do puncionamento do AHSS Ferrítico-Bainítico (FB590) em temperaturas ambiente e criogênica

• Ano de defesa: 2023
• Autor(a) principal: Barbosa, Jonas Medeiros de Azevedo
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal do Rio Grande do Norte; Brasil; UFRN; PROGRAMA DE PÓS-GRADUAÇÃO EM ENGENHARIA MECÂNICA
• Palavras-chave em Português: Aço FB590; Puncionamento criogênico; Correlação de imagens digitais; Método dos elementos finitos; Simulação numérica; CNPQ::ENGENHARIAS::ENGENHARIA MECANICA
• Link de acesso: https://repositorio.ufrn.br/handle/123456789/57756

Advanced High Strength Steels (AHSS) have been used for vehicular structures aiming for mass reduction with a feasible balance between mechanical resistance and formability in manufacturing processes. Those steels are commonly supplied in thin sheets and must be manufactured typically by forming processes to define the product shape, and punching is one of the critical operations. The AHSS Ferrite-Bainite (FB) stands out for having high local formability, allowing structural reinforcements like flanges to be obtained. Furthermore, processing AHSS involves high strength and plastic elongation values, and the material’s behavior changes during the operation due to processing parameters such as die clearance, punch geometry, and temperature. Models to evaluate the effects of operations above room temperature are available in the literature, but there is a lack of studies at cryogenic temperatures. This research aims to simulate the behavior of the AHSS FB590 material at room and cryogenic temperatures to analyze the ductile-brittle transition effects at the cutting edge. A methodology to obtain values of triaxiality and plastic strain needed for calibration of the constitutive models was developed using digital image correlation (DIC) to determine the fracture moment. The hole expansion simulations showed that an increment of 4.7 mm on the final diameter can be obtained by changing the previous punching operation from room to cryogenic temperature.