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Information × Registration Number 0221U000005, 0118U000462 , R & D reports Title Establishment of material science, mechanical and electrochemical diagnostics informative features of structural steels corrosion-hydrogen degradation popup.stage_title Head Nykyforchyn Hryhoriy M., Доктор технічних наук Registration Date 02-01-2021 Organization Physico-Mechanical Institute named after GV Karpenko of the National Academy of Sciences of Ukraine popup.description2 Some methods, including materials science, mechanical and electrochemical ones, have been developed for assessing the operational degradation of carbon and low-alloy steels under the action of corrosive-hydrogenating environments, besides, the surface hardening methods have been adapted taking into account the action of the corrosion-hydrogen factor. The criterion for achieving a critical, due to operation, state of carbon and low-alloy rolled steels is substantiated by a part of not more than 11% of the elements of microcracking on fracture surfaces of impact specimens. It is proposed to determine the electrochemical properties of fracture surfaces to assess the current state of operated steels. On this basis, an electrochemical method for assessment of operational degradation of steels has been developed, which is based on the established correlation between operational changes in the resistance to brittle fracture of metal and the electrode potential of its fracture surface. It is shown that for corrosion-fatigue crack growth tests in pipeline steels, their operational degradation is most manifested by the susceptibility to stress corrosion cracking. Thus, we recommend to perform tests with increased asymmetry of a loading cycle and cathodic protection potential. A method for the fatigue crack growth inhibition in carbon and low-alloy steels in the range of the middle part of the fatigue crack growth curve by an artificial creation of the crack closure effect is proposed using a special technological environment. It is established that the surface nanostructuring of steels and cast irons by mechanopulse treatment increases effectively their resistance to wear, corrosion- and contact fatigue. This anables to develop and implement appropriate technologies of surface hardening for critical parts and structural elements, which ensures an increase in their service life by 2.5-2 times compared to the same parts of factory production.  Product Description popup.authors Voloshyn Vitaliy A. Hredilʹ Myroslava I. Dem'yanyshyn Nataliya M. Zvirko Olʹha I. Kyryliv Volodymyr I. Kost' Yaroslav P. Kret Nataliya V. Krechkovsʹka Halyna V. Kurnat Ivan M. Maksymiv Olʹha V. Mytsyk Bohdan G. Moskva Mykhaylo I. Nykyforchyn Hryhoriy M. Svirsʹka Lesya M. Student Oleksandra Z. Khabursʹkyy Yaroslav M. Tsyrulʹnyk Oleksandr T. Shtoyko Ivan P. popup.nrat_date 2021-01-02 Close