研究速報 : Microstructure Simulation in Hot Open Die Forging by Using the Incrementa Formulation (Preliminary Report)

Knowledge about microstructure evolution during hot forging is the key technology to optimize austenite grain size and mechanical properties of forged product. A lot of researches have been made with aims to analyze microstructure evolution during hot forming. However, most of them have been focused on the hot rolling pro."rrt) and only a few reports have been presented about forging pror*r..t) Present investigation attempts to establish an adequate microstructure simulation model for hot open die forging. In hot open die forging, strain rate distributes in a wide range so that an adequate microstructure simulation model to deal with mixed recrystallizations (static, dynamic and metadynamic recrystallizations) is indispensable. The term of critical Zener-Hollomon parameter is introduced as an indicator to distinguish static microstructure change from dynamic microstructure change. Predicted austenite grain size was compared with experimental measurements.