Prediction of microstructure evolution of Al–1% Mg alloy during hot forming and sequential heat treatment

Abstract

The microstructure evolution during hot forming and sequential heat treatment was simulated to guide the process design by using the finite element method (FEM). The microstructure change under varying deformation conditions during hot forming was investigated. These formulations were implemented into a commercial finite element code to analyze microstructure evolution during hot forming and heat treatment. Static recrystallization, dynamic recrystallization and meta-dynamic recrystallization were taken into account. The FE module was applied to analyze the microstructure change of Al–1% Mg alloy. Al–1% Mg is very different to the steels since it does not appear to undergo dynamic (or, therefore, metadynamic) recrystallization because of the high rate of dynamic recovery. Static recrystallization was considered in the paper. The influence of transient strain rate deformation conditions on the deformed microstructure of Al–1% Mg was studied by using numerically analytical method and FEM. The simulated stress and microstructure change were compared with published experimental and analytical results. The evolution of grain structure for Al–1% Mg steering link forging (1999 German Forging Industry Association Benchmark) and sequential heat treatment was simulated using the 3D FE simulator combined with a microstructure module. The forging with finer grain structure is obtained by annealing for 2 h at 400 °C.