The method of diffraction electron microscopy was used to study the influence of the tempering period on the defect structure of the Fe-0.38C-3.5Ni-1.3Cr-0.24Si-0.35Mn-0.4Mo-0.15V-0.3Cu cast construction steel. It was demonstrated that tempering caused the sub-structural non-fragmented → fragmented sub-structure transformation, which was the main sub-structural transformation. Three types of fragments were formed, including initial and anisotropic secondary fragments with network and cellular dislocation sub-structures and tertiary isotropic dislocation-free fragments. The fragmentation process at tempering was accompanied by a continuous decrease in the scalar dislocation density.

Influence of Tempering on the Dislocation Substructure and Scalar density for Cast Construction Intermediate-Alloyed Steel. E.V.Kozlov, N.A.Popova, S.I.Klimashin, V.E.Gromov, N.A.Koneva: Russian Physics Journal, 2006, 49[1], 47-54