STRUCTURE FORMING PROCESSES DURING HOT DEFORMATION OF A C-MN-V-N STEEL

Medium carbon V-N treated steel grade applied for long products and sm all drop forged parts investigated in a state of incomplete solution o f V(C,N) precipitates. Activation energy changes investigated in the 8 50-1200 degrees C temperature range and 0.6-30 s(-1) strain rate range is revealed to be temperature dependent. Calculated for sigma(p) flow stress Value this energy in some cases expresses a combination of var ious processes. It is found that DRX starts well below epsilon(p) Soft ening during a short interpass time is caused by dynamic recrystalliza tion DRX during forming and is followed by metadynamic recrystallizati on MDRX and static recrystallization SRX. At longer interpass times so ftening progress is hindered by precipitation.