Characterization of dynamic recrystallization parameters for a low carbon resulfurized free-cutting steel

摘要

The hot working behavior of a low carbon resulfurized free-cutting steel was studied by hot compression tests at temperature range of 1000-1200℃ with strain rates of 0.001 to 1 s~(-1). The conventional parameters such as activation energy of deformation and relationships between flow stress/strain and Zener-Hollomon parameter were determined. Both the critical stress and strain for initiation of dynamic recrystallization (DRX) were determined using: (1) strain hardening rate versus stress curve, (2) the natural logarithm of strain hardening rate versus strain curve, and (3) the constitutive equations. In summary, for low carbon resulfurized free - cutting steels, the activation energy of deformation was found to be 330 kj/mol and the DRX was found to start when the normalized stress and strain reach to the values of 0.87 and 0.50, respectively.