Hot deformation of austenite and prediction of microstructure evolution of cross-wedge rolling

Constant strain rate compression tests were carried out on AISI 5140 using the Gleeble-3500 thermomechanical simulator. The mechanical behavior and the dynamic structure changes were investigated metallographically in the temperature range from 900 to 1100 degreesC and at the strain rate ranging from 0.1 to 10 s(-1). A dynamic recrystallized grain size model and a volume fraction model were presented as well as a diagram of dynamic microstructure state. The cross-wedge rolling process for shafts was simulated through establishing a theoretical model on the finite element software DEFORM. The distributions of the different field-variable, such as effective strain, effective strain rate and temperature, were obtained. Meanwhile, mean grain size distribution after rolling was presented in this paper. (C) 2004 Elsevier B.V. All rights reserved.