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Information × Registration Number 0221U100463, 0120U101256 , R & D reports Title Development and research of principally novel structural materials with guided structure for operational and future reactors to enhance the safety and economy of nuclear power popup.stage_title Head Voyevodin Viktor M., Доктор фізико-математичних наук Registration Date 05-01-2021 Organization National Science Center "Kharkiv Institute of Physics and Technology" popup.description2 The modes of severe plastic deformation (SPD) and following heat treatment of ferritic-martensitic steel T91M were optimized. SPD was processed by the method of cyclic "extrusion - upsetting" in the interval of temperatures of ferrite phase stability (750 – 575 ºС). Heat treatment of SPD steel was carried out at temperatures of 550-730 ºС for 1-100 hours. It was established that the lowering of the temperature during SPD and the increase in the number of cycles leads to a decrease in the average grain size up to 145 nm and an increase in the step of uniformity of the microstructure. In this case the microhardness of steel increases from 1800 to 2850 MPa. The strength characteristics in the temperature range -196 ... +550 ºС (yield strength 0,2 and strength в) of T91M steel with submicron ferrite microstructure obtained by SPD and SPD followed by heat treatment exceed the characteristics of steel with martensitic microstructure obtained by standard technology " normalization + heat treatment". At the same time the plasticity of steel remains at an acceptable technological level. Comparison of the results obtained with the literature data for steel T91M subjected to SPD by torsion under pressure and equal-channel angular pressing shows that the method of multiple "extrusion - upsetting" makes it possible to decrease grains size and improve mechanical characteristics no less efficiently than others SPD methods. The advantage of our method is the ability to improve the microstructure of industrial-sized workpieces, as well as the simplicity of the technological equipment used.  Product Description popup.authors Bilous Vitalii A Kuprin Olekcander S Tikhonovsky Mikhaylo A popup.nrat_date 2021-01-05 Close