Shvachko V. The reversible hydrogen embrittlement of BCC-iron alloys - structural steels

The reversible hydrogen embrittlement (RHE) of BCC-iron alloys-structural steels - creates the serious technological difficalties, because the physical nature of this specific and complicated phenomenon does not disclosed. In the thesis the theoretical generalization and new decision of this problem are presented. It is shown, that the plastic deformation, which initiates the microcracks in the body of metals, is a main condition of RHE development. Hydrogen is transported by the moving dislocations to a point of microcrack initiation. This microcrack can collapse, remain in the elastic equilibrium state or indifinitely grows. Hydrogen, which is evolved from the dislocation, is chemisorbed at the microcrack surfeces and localizes the negative charge. This results in a decrease of normal stresses required for the microcrack autocatalitic propagation. These ideas allow us to explain all features of RHE and creates the scientific basis for the development of methods of its prevention