[en] The testing machine design is suggested that permits to test small-size specimens on impact tension at low temperatures under stable temperature conditions. The design of the machine is given schematically and specimen types applied are represented. Armco- iron was tested to show the expedience of using the machine suggested for determination of resistance to crack propagation and tendency to brittle fracture on non-standard specimens

[en] Studied are the structural changes in the process of low-cyclic loading of the Kh18N10T and Kh20N45N5B austenitic steels at different temperatures. The effect of these changes on mechanical properties of the steels, such as hardness, ductility, fatigue, microcracking etc., is studied, as well

[en] A new method of heat treatment of the chromium-molybdenum-vanadium steel is suggested. To increase steel impact strength, isothermal hold time is carried out at 620-660 deg C, and annealing - at 660-720 deg C. The invention relates mainly to power machine-building and can be used during heat treatment of products made of chromium-molybdenum-vanadium steels operating at 550-575 deg C. The method suggested is shown to allow to increase the strength and the impact strength of low-alloyed chromium-molybdenum-vanadium steel without additional alloying which increases its cost and decreases production effectiveness

No abstract available

[en] A new method of heat-resistant coating of niobium alloy products is suggested. The method consists of the treatment at 900-1100 deg C in liquid-metal melt, containing saturating elements. To increase the heat resistance of coatings, as well as to simplify the process of coating, the treatment is conducted in sodium base melt containing Al, Si, Ti, Cr (5-10 %) as saturating elements

[en] Papers dealing with high-temperature strength of high-alloyed steels, niobium and molybdenum alloys used as construction materials in reactor building are reviewed. The necessity of testing large batches of samples under identical loading conditions on special multipositional devices is stressed. The effectiveness of increasing the carrying ability of refractory metals and alloys by combined strengthening (solid solution and dispersion) is noted. The advisability of using multilayer diffusion coatings to protect refractory metals from the effect of operating media is shown

[en] Microfractographic peculiarities of destruction of the 15Kh2MFA steel after short- and long-term loadings are investigated. It is established that the decrease in resistance to strain toughness by stage-by-stage shifts is one of the reasons for acute steel fracture. The role of this mechanism is particularly significant in the fracture process of samples aged under voltage at 550 deg C

No abstract available

[en] The stability of the structure of a recrystallized 5VHTs niobium alloy in the course of prolonged high-temperature holding in vacuum under stressed state was studied. Using optical and transmission electron microscopy techniques. Investigated was sheet deformed material after a recrystallizing annealing at 1400 deg C for 1 h with subsequent aging at 900 and 1100 deg C. The investigation indicated that the aging of the 5VMTs alloy at 900 and 1100 deg C involves a partial dissolution of disperse carbides of ZrC and Nb₂C and their fragmentation. MeC type carbides of globular shape, the amount of which remained almost without variation on increase of the aging time to 5000 h, are produced at 1100 deg C after several hundreds of hours

[en] The phase composition, dislocation structure and morphology of carbide precipitates in the Nb-1%Zr-0.1%C alloy are investigated after long-term holding (5000 and 10000 hrs.) at 900 deg C. It is shown that the long-term holding at 900 deg C under loading or without it leads to the decrease in creep resistance, to coarsening of carbide particles and increase of the carbide phase content in comparison with the initial state. During the test of the alloy under loading the particles also coarsen, but their average size decreases due to large amounts of fine dispersion precipitates (the size up to 400 A) in the structure. The results of study of mechanical properties and structure indicate the changes in geometry of carbide particles and formation of carbide precipitates of M₆C type after 5000 and 10000 hrs. holdings