MODEL FOR INTEGRATED PROCESS AND MICROSTRUCTURE SIMULATION IN HOT FORMING

The paper presents a model offering improved implementation of material behaviour in plastomechanical simulations of hot-forming processes. Microstructural states at any instant during forming are evaluated successively on the basis of semi-empirical equations determining the state of dynamic recrystallization, and the corresponding flow stress is inferred. Upsetting tests were used to determine the characteristic data for a Cr-V steel in a spectrum of theta = 830-1150-degrees-C, epsilon = 0.05-5 s-1 and d(o)gamma = 70-108-mu-m. The developed model is used to simulate upsetting tests, validating its accuracy in terms of structural description and flow-stress determination.