Keyword: «size effect»

A brief historical excursus and a modern overview of research in the field of scale effect are presented, as well as the theoretical insights and experimental data on the effect of material structure on its strength characteristics. Considered, in particular, low-alloy steels St3sp and 09G2S in the state of delivery and after equal-channel angular pressing and heat treatment. Arguments for explaining the Hall-Petch dependence as a scale effect are presented. Violation of this regularity on the nanoscale can be explained by the change of the deformation mechanism, which has a bifurcation character, which can be explained on the basis of the developed system-structural approach.