Influence of complex hierarchy on the distribution of brittle cracks in bainitic and martensitic steel structure

Goal. Analysis of the propagation of transgranular and intercrystallite cleavage in bainitic structures, and methods for producing structures with a fairly complex hierarchy to stop brittle crack. Results. The above construction steel are characterized by a complex hierarchy, the receipt of which is possible by subjecting the steel rolling heating after rolling and using doping. It lowers the threshold of cold brittleness, increases resistance to brittle fracture of steel, which is due to a refinement of the structure and an increase in the mechanical properties of complex steel. Conclusions. In this paper we analyzed the propagation of a brittle crack in the intermediate structures. The advantages of steel with a complex hierarchy of grain, such as acicular ferrite, low carbon lath martensite, which allows to suppress brittle fracture during its propagation in the body of structure.