Electron concept for hydrogen brittleness of metals

Information from scientific report at the meeting of Presidium of NAS of Ukraine December 10, 2014

Abstract

Hydrogen effects on the physical and mechanical properties of materials are studied by means of first principles calculations and experimental methods. It is shown that hydrogen enhanced localized plasticity model adequately describes the phenomenon of hydrogen embrittlement of metals. Nevertheless its description within the framework of continuum mechanics overestimates the level of hydrogen induced shielding of elastic interactions between dislocations and also doesn’t take into account the hydrogen effect on the electron structure. Taking into account the peculiarities mentioned, the electron approach of hydrogen brittleness is developed, according to which the cause of hydrogen induced brittleness is its influence on the electron structure of materials and, as a consequence, on the elastic moduli. Based on the electron concept the practical recommendations for the increase of the resistance from hydrogen brittleness of austenitic steels are developed.