STRAIN-HARDENING OF STEELS AT LARGE-STRAIN DEFORMATION .3. MODEL DESCRIPTION AND PHYSICAL INTERPRETATION

Based on the development of dislocation cell structures during plastic deformation and on the results of computer simulations, a new cell st ructure-based (CSB) model has been proposed in this part of the work. It is an improvement on the Prinz-Argon model. In comparison with Prin t and Argon the CSB model enables an analytic correlation between macr oscopic stress and strain to be made. In this new model, the two effec ts of dynamic recovery, dynamic annihilation and reorganization of dis locations, can be taken into account. The entire deformation can be de scribed by this model. According to the model, the remaining strain ha rdening rate at stage IV is caused by the multiplication of dislocatio ns in the cell interiors. Thus it is not the local flow stress but the local dislocation density change which determines the strain hardenin g. The Kocks model can be obtained from the CSB model if some simplifi cations are made.