Extrapolation of flow curves at hot working conditions

Many experimental dynamic recrystallization (DRX) flow curves are incomplete and extrapolating to higher strains is required to construct the complete stress–strain curves. In the present work, the DRX flow curves of a 17-4 PH stainless steel were modeled and generalized using the constitutive equations and Avrami description of DRX. The flow softening was directly related to DRX volume fraction, and the DRX time was determined according to the definition of strain rate. The Avrami kinetics was found to be suitable for extrapolation of flow curves to higher strains. This method is useful to overcome the restrictions of some deformation processes such as hot compression.