Model of hydrogen embrittlement of constructional steels

The serious technological problems are caused by a reversible hydrogen embrittlement (RHE) of structural (constructional) steels; however, a mechanism of this complicated phenomenon is studied unsufficiently. In a given paper, a new physical model of RHE is presented and based on the microcleavage conception. In accordance with this model, the plastic deformation is a main condition of RHE development. When the hydrogen atoms involved come off from the dislocations, they are chemisorbed at the microcrack surfaces and localize. a negative charge. This redistribution results in a decrease of normal stress required for the microcrack autocatalytic propagation in a field of external stresses. The examples of an application of this model are presented.