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Information × Registration Number 0214U000176, 0112U006483 , R & D reports Title Researching of the influence of nano-formation on microstructure welded seams of high-strength low-alloyed steels for working under extreme conditions popup.stage_title Head Fomichov Sergiy Konstantinovich, Registration Date 21-01-2014 Organization National Technscal University of Ukraine "Kiev Polytechnic Institute". popup.description2 Report compiled for the first stage at 118 pages , in one part , contains 76 illustrations , 19 tables and a list of references from 92 sources. Object of study - the microstructure of weld metal of low alloyed high strength steels . Purpose - to study the influence of the concentration and composition of the oxide nanopowders on the formation of the microstructure of the weld and its mechanical properties . Research methods and apparatus - when doing research used methods of optical and electron microscopy , X-ray diffraction analyzes r and computer programs for the analysis of microstructural components and distribution of non-metallic inclusions in size and composition . Results and innovation - it is established that depending on the amount and composition of nonmetallic inclusions in the weld metal a different type of a bainitic microstructure with precipitation of acicular ferrite is formed. It is proved that this effect is manifested when the nano additives are introduced into the molten pool under the scheme , which provides pre- melting inherent in bevels sintered rods of iron powders and oxide nanopowders . It has been established that when the volume fraction of the nano alumina from 0.5 % to 4.5 % of the most effective impact on the structure appears when it is introduced into the welding pool in an amount of 0.5 % by volume . The main feature of this structure is a high degree of commination and dispersion of the components , which greatly strengthens the weld metal and increases mechanical properties. Product Description popup.authors Головко В.В. Кузнецов В.Д. Лобода П.І. Смирнов І.В. Фомічов С.К. popup.nrat_date 2020-04-02 Close