The effects of rare earth (RE) elements on the carbide distribution, transformation temperature, and mechanical properties of H13 die steels after annealing were systematically investigated by scanning electron microscopy, electron probe microanalysis, and transmission electron microscopy. The results indicated that the addition of RE elements is helpful in increasing the fraction of the disrupted M₂₃C₆ carbide along the grain boundaries, hindering the migration of grain boundaries and improving the crack-formation and expansion resistance of the carbides in the tensile process. With the addition of RE, the Ac₃ temperature increased by 11.4 °C and the diffusion of carbon atoms was pinned during the austenitizing process. Moreover, the carbides were modified by rare earth elements, and RE-inclusion promoted the transition of brittle-type failure to ductile-type failure. Therefore, the impact energy, hardness, and ultimate tensile strength improved significantly in the RE-modified H13 die steels.

To study the nucleation and recrystallization behavior of deformation bands, shear bands and grain boundaries during the recrystallization process, a heat treatment test was carried out on Cr-Ti-B low-carbon steel after warm rolling and cold rolling. The results show that recrystallization occurs preferentially in shear bands and grain boundaries. The γ deformation texture can be enhanced and the Goss texture can be weakened during the warm rolling and subsequent cold rolling process. Recrystallization of the deformation bands was observed, but the nucleation time of recrystallization in the deformation band is much slower than that in the shear band and grain boundary.