Development of dynamic recrystallization theory

Although hot working had been defined as deformation above the recrystallization temperature (determined after cold working), it was only about 1965 that dynamic recrystallization (DRX) was confirmed to be occurring during the deformation; two decades were required to clarify the similarities to, and the differences from, static recrystallization. In classical discontinuous DRX in Cu, Ni, and γ-Fe, successive necklaces of new grains cause work softening; however in steady-state, the nuclei are uniformly distributed as reestablished dislocation structure limits growth. In high recovery metals at high strains, the grain boundary (GB) serrations meet across the elongated thinned grains thus pinching them off into almost equiaxed grains containing a substructure, thus geometric DRX.