Incremental Formulation for the Prediction of Flow Stress and Microstructural Change in Hot Forming

In metal forming, the workpieces are formed to the desired shapes or profiles. Especially in in hot forming, the microstructure of workpiece changes during plastic deformation. Modern forming technologies allow to control the shape and the microstructure of formed product in a wide range and will gain increasing importance in future in the field of metal forming. In order to develop this forming technology which may be called macroscopic microscopic materials processing. theoretical predictions of plastic deformation as well as microstructural changes are indispensable. A new mathematical formulation to predict flow stress and microstructural change in hot forming will be presented in this paper. This model is based on an incremental formulation taking the dislocation density as a representative variable.