Luana De Lucca de Costa

Optimizing Hot Forging Process Parameters of Hollow Parts Using Tubular and Cylindrical Workpiece: Numerical Analysis and Experimental Validation

CAE (computer aided engineering) evaluates the forging process virtually to optimize the industrial production. The numerical and experimental investigations of forging process of a hollow part are important in industrial point of view. This study has been focused on the development of a 3D elastic-plastic FEM (finite element model) of hot forging to evaluate the forming process of hollow parts. The validity of this method was verified through a laboratory experiment using aluminum alloy (AA6351) with medium geometric complexity. The distributions of effective strain, temperature, metal flow and strength were analyzed for two different initial workpieces (tubular and cylindrical). It was observed that both initial workpieces can be used to produce the final hollow part using the numerical simulation model. The results showed that the numerical analyses predict, filling cavity, calculated strength, work temperature and material flow were in agreement with the experimental results. However, some problems such as air trapping in the die causing incomplete filling could not be predicted and this problem was resolved experimentally by drilling small holes for air release in the dies.

ESTUDOS COMPARATIVOS DOS MÉTODOS DE CÁLCULO COM RESULTADO EXPERIMENTAL DO ALARGAMENTO NO PROCESSO DE LAMINAÇÃO A QUENTE DO AÇO AISI1020

Resumo Este estudo descreve a aplicação de três métodos de cálculos teóricos pelos modelos matemáticos de Tafel e Sedlaczek, Siebel e Köster, com o objetivo de calcular o alargamento na laminação a quente de barras em aço AISI 1020 em um laminador tipo duo e definir quais dos modelos de alargamento se aproxima mais dos resultados obtidos experimentalmente. Foram utilizadas amostras com dimensões iniciais de largura (bo), 37,7 mm, altura (ho), 15,7 mm, e comprimento (lo), 300,00 mm onde se ajustou a luz dos cilindros para que fossem obtidas reduções aproximadas de 15% e 20% em altura. Os resultados obtidos indicam que o modelo de Siebel apresenta melhores resultados comparado com os valores experimentais. Palavras-chave : Laminação a quente; Modelos matemáticos.