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Information × Registration Number 0221U104653, 0118U000181 , R & D reports Title Research of efficiency and the choice of physico-metallurgical methods for controlling the properties of welded joints of low-alloy steels of increased strength made under water popup.stage_title Head Maksymov Serhii Yu., Доктор технічних наук Registration Date 06-04-2021 Organization E.O.Paton Elektric Welding Institute National Academy of scinces of Ukraine popup.description2   Based on the experiments and using a mathematical model of the process of interaction of the external electromagnetic field with the welding arc's electromagnetic field, taking into account the influence of eddy currents in the welded product, the optimal range of external electromagnetic effects is 6… 20 mT. In this case, the lower limit is determined from the condition of exceeding the intensity of the external electromagnetic field over the vortex magnetic field's intensity, which is created by the arc. The upper limit is due to the transition from the lamellar flow of the melt to the turbulent. By modelling the hydrodynamic processes in the welding pool, the nature of the detected effect of reducing the porosity of the joints is established. It consists of the fact that in addition to the Archimedean force, the external electromagnetic field causes a centrifugal force, which acts on the gas bubble and removes it from the liquid metal bath. Moreover, its value is several times greater than the power of Archimedes. It is shown that the efficiency of the centrifugal force on the bubbles increases with increasing diameter. When welding in the ceiling position, it will be crucial for the removal of bubbles. Based on the performed researches and the received results, electrode materials and technological recommendations on the use of external electromagnetic influence, which provide the increased level of plasticity of weld metal concerning the restoration of underwater metal constructions, are created. Technological instructions for welding the underwater part of the bridge crossing supports across the Dnieper River in Kyiv have been developed. Industrial testing of the heat exchanger tubes in Crayford, UK, at a depth of 207 m, showed that the use of wet automatic welding with flux-cored wire could increase the reliability of the heat exchanger, reduce time losses when performing sealing work, rationally use the installation area, reduce financial expenses. Product Description popup.authors Vasilyev Dmytro V. Gavrilyuk Anatoly A Krazhanovsky Denis M Lyakhova Inna V Prilipko Olena O Radzievskaya Alla A Sidoruk Volodymyr S Shepelyuk Julia A popup.nrat_date 2021-04-06 Close