The microstructure optimization of H-shape forgings based on preforming die design

A microstructure optimization design method of the forging process is proposed. The optimization goal is a small grain size and a homogeneous grain distribution of the forgings. The optimization object is the preforming die shape. The microstructure optimization code is developed using the micro-genetic algorithm and the finite element method. The two forming steps including the preforming process and the final forging process of H-shape forgings are analyzed using the self-developed code. The optimization results show that small grain size and homogeneous grain distribution can be achieved by controlling the shape of the preforming die. Samples of the same size as in the optimization are preformed and then forged to the desired H-shape forgings under the same deformation conditions as in the optimization. Micrographs in the symmetry section of samples show that the grain sizes of the forgings almost coincide with the optimization results. (C) 2008 Published by Elsevier BY.