NUMERICAL-SIMULATION OF THE EVOLUTION OF THE MICROSTRUCTURE IN CLOSED-DIE FORGING

In the present project a computer code, developed for the thermo-mecha nical modelling of the axisymmetric compression test, is adapted to th e analysis of the problems associated with closed-die forging. The pre dictive ability of this model is validated experimentally in single an d multi-stage compression tests. The calculated distributions of the g rain size over the cross-section of the samples are compared with the data from experiments. The model is then adapted to analyze the proble m of closed-die forging, using an arbitrarily shaped die. Treatment of the nodes in contact with the die and those losing contact is a speci al feature of the computer code. An automatic remeshing procedure is i ncluded. The model predicts the distributions of strain rates, strains , stresses, temperatures and grain sizes. The results of calculations for a typical die shape are presented in the paper.