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Information × Registration Number 0203U006573, 0100U004860 , R & D reports Title Investigation and assessment of corrosion welding joints fracture of different geometry on the base of consideration of local synergistic factors of stress concentration and operating environment in welded zone popup.stage_title Head Dmytrakh I.M., Registration Date 12-06-2003 Organization Karpenko Physico-Mechanical Institute of the National Academy of Science of Ukraine popup.description2 Object of investigations - welded joints of different geometry and joints "anticorrosive overlay - hull steel" under simultaneous action of mechanical loads and corrosion environments. Aim of work - development of experimental and analytic approaches and criteria determining of corrosion fracture of welded joints with take into account of stress concentration (caused by their geometrical specificity) and local physical and chemical processes of environmental interaction with metal at welded zone. Methods of investigations - combination of experimental and analytic approaches of materials fracture mechanics with simultaneous using of the methods of electrochemistry, physical chemistry and materials science. The new experimental and analytic methods for assessment of local corrosion and local fracture of welded joints are developed on the base of their consideration as complicated heterogeneous systems. The new mathematical models for stress field calculations in welded joints of different geometry are proposed. On this base the electrode potentials calculations have been done that give the possibility to evaluate the area of higher corrosion activity of the given welded joints. The numerical method of "equivalent electrode" for determination of electrochemical current density from the surface corrosion pit in three-layered material is developed. For the first time, the diagrams of corrosion resistance and corrosion crack growth resistance of welded joints "anticorrosive overlay - hull steel" are constructed. These diagrams are the base for assessments of residual lifetime and development of methods for preventing of corrosion damaging of welded joints under long-term exploitation. The analytic relation for assessment of corrosion fatigue durability has been derived and experimentally verified. This formula binds the cyclic stress range, size of corrosion fatigue crack, number of loading cycles, maximal corrosion current and constants of metal electrochemical dissolution. Area of application - assessment ofstrength, durability and exploitation safety of the critical structures and technological equipment for power engineering and other branches of industry. Product Description popup.authors popup.nrat_date 2020-04-02 Close