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Information × Registration Number 0221U106651, 0120U104904 , R & D reports Title Physico-mechanical macro, micro and nano mechanisms of hydrogen interaction with low-alloy steels as a fundamental factor in the strength and performance of hydrogen storage and transportation systems popup.stage_title Head Dmytrakh Ihor M., Доктор технічних наук Registration Date 16-12-2021 Organization Physico-Mechanical Institute named after GV Karpenko of the National Academy of Sciences of Ukraine popup.description2  For the first time, on the basis of special experimental studies, the diagrams „strength and plasticity characteristics – hydrogen concentration in metal”, that define three main levels of the hydrogen concentration in metal, which have their own characteristic mechanisms of hydrogen effect on the low-alloyed steels, were built. It is established that at the low hydrogen concentrations of 0.010.2 ppm the plastic deformation of the metal is facilitated, and at the concentrations of 0.810 ppm the mechanism of hydrogen embrittlement of the material is completely dominated. The range of hydrogen concentration of 0.20.8 ppm is a transition zone where the simultaneous coexistence of these two mechanisms is possible. For the first time, the basic diagrams „resistance to local fracture – hydrogen concentration” for low-alloyed steels in the presence of the mechanical stress concentrator and crack-like defect in the material, were constructed. These diagrams have three characteristic zones that correspond to different features of the hydrogen influence mechanisms on the fracture resistance of low-alloyed steel: the zone of enhanced deformability of material, the transition zone with the mixed mechanism of hydrogen effect and the zone of hydrogen embrittlement. The value of the critical hydrogen concentration (0.60.7 ppm) was determined, at which the material local resistance to fracture significantly decreases. The peculiarities of the mechanism of plasticity limit decreasing caused by hydrogen were established. This mechanism consists in the generation of void-like defects on nano, micro and macro levels, which facilitate the deformation of the material and reduce its resistance to fracture. The realization of such a mechanism leads to the formal reduction in the value of the plasticity limit as a macroscopic characteristic of the material. Product Description popup.authors Hembara Nazar Т. Hembara Oksana Volodymyrivna Hrynenko Mykhajlo V. Dmytrakh Ihor Mykolayovych Sapuzhak Yaroslav Іhorovych Syrotiuk Andriy Mykhaylovych popup.nrat_date 2021-12-16 Close