Sheets from a pipe steel rolled in the finishing stage of controlled thermomechanical treatment (TMT) above and below the onset temperature of γ → α transformations are studied. The structure and texture of specimens are determined by metallographic analysis; impact bending and tension tests are performed. The structural heterogeneity formed during rolling below A3 was shown to have a significant effect on the steel structure after controlled cooling. The structure acquires regions of a homogeneous crystallographic texture elongated in the rolling direction, which form preferential sites with the lowest fracture energy for secondary crack propagation. Such processes decrease the total running fracture energy in gas pipelines made of high-strength steels.