The investigations carried out are dedicated to the analysis of the material impact of the loading environment upon the effectiveness of a shock pulse at wave deformation strengthening. To carry out investigations in the specialized program there is developed a finite-element model of an impact system consisting of a head and a waveguide pressed statically to the environment of loading. The impact system effectiveness was estimated on the ratio of shock pulse energy imparted to a deformation source taking into account the material of the loading environment to the energy of a head blow to a waveguide. It is defined that the most significant impact upon a share of transient energy of the shock pulse is rendered by the head parameters the change of which in the range considered allows increasing the effectiveness of the impact system by 15.6 times. The next important factor affecting considerably the effectiveness of shock pulse energy transfer is a ratio of the lengths of a head and a waveguide the change of which in the value range investigated allows increasing a share of energy transferred by 2.8 times. The least impact upon the effectiveness of impact energy transfer in the center of deformation with the impact system is performed by the material of loading environment – 1…3% for the rational values of the parameter ratios of the impact system elements (n more than 80%). At the forced choice of less efficient impact systems (L1/d1=1 ; L1/L2=1…10; n less than 62%) the impact of the material of loading environment may make 6…10%.

МИКРОСТРУКТУРНЫЕ ИЗМЕНЕНИЯ В СТАЛИ 45, ВЫЗВАННЫЕ ВОЛНОВЫМ ДЕФОРМАЦИОННЫМ УПРОЧНЕНИЕМВ результате микроструктурных исследований образцов из стали 45 установлено, что с увеличени-ем равномерности волнового деформационного упрочнения в поверхностном слое протекает ряд процессов. При небольшой равномерности упроч-нения формируется развернутая на угол 45° волок-нистая структура и глобулярный феррит. При воз-растании равномерности упрочнения сначала про-исходит выстраивание перпендикулярно деформи-рующему усилию зоны полного диспергирования феррита и перлита, а затем образование высоко-дисперсных зон в форме линз -переупрочненных областей.Ключевые слова: микроструктура, упрочне-ние, волна деформации, феррит, перлит, равномер-ность, гетерогенность, глобулярность.A.V. Kirichek, S.V. Barinov, S.V. Davydov, A.V. Yashin, A.A. Zaitsev, A.M. Konstantinov MICRO-STRUCTURAL CHANGES IN STEEL 45 CAUSED BY WAVE STRAIN STRENGTHENINGThe application of surface plastic deformation (SPD) for the formation of a heterogeneous structure became possible with the advent of wave strain strengthening (WSS). In contrast to well-known SPD methods this method allows ensuring a required law of the distribution of solid and viscous areas at a large depth and ensures the absence of a sharp boundary between the areas with different hardness and viscosity which excludes stress concentration and does not cause micro-cracks nucleation. Earlier, with the aid of WSS one managed to increase a resistance to a contact crumbling by a factor of three -five times, and a breaking pointup to 8% on flat samples of steel 45. In the work there were carried out investigations of micro-structural changes occurred at different uniformities of the wave strain strengthening on flat samples of steel 45. As a result of investigations it was established that in a surface layer from the side of a deformation source with the increase of strengthening uniformity (from K = 0.2 up to K = 0.8), because of the increase of deformation impact density per unit area of a surface the thickness decrease of the visible grain deformation area takes place. The thickness increase of visible grain deformation area on the opposite (back) side begins with the value of K = 0.6 and higher. At WSS with surpassing K=0.2; 0.4, on the back side at K=0.8 there is arisen a formation of fibrous textured structure in which grains are unfolded to the angle of 38-41º. At the wave strain strengthening with K=0.4 there is determined a formation of globular ferrite in a surface layer.Key words: micro-structure, strengthening, deformation wave, ferrite, pearlite, uniformity, heterogeneity, globularity. ВведениеДостаточно большой интерес для со-временной промышленности представляют гетерогенные материалы, например соче-тающие высокие параметры ударной вяз-кости и твердости. Материалы с гетеро-генной структурой, в отличие от компози-ционных материалов, имеют однородный химический состав, а гетерогенные свой-ства задаются в гомогенном материале технологически, например термообработ-кой (ТО) или химико-термическ...

The article raises the problem of visualizing fleeting processes occurring as a result of wave strain hardening (WSH). The features of this method are unique capabilities for controlling the parameters of the shock pulse. This allows, in contrast to other dynamic methods of the surface plastic deformation, forming the desired microhardness distribution diagram in the surface layer at a depth of 6- 8 mm, while ensuring the required uniformity of hardening. The need to visualize this method is explained by the complexity of the analytical description of the ongoing wave processes in the shock system and the loading medium. Developing a visualization technique based on a model of the process of wave strain hardening consists of several stages. The stages include setting the initial and boundary conditions of the simulated elements, their physical-mechanical properties, loading conditions, the type of the mesh, the process conditions. The created model allows you to visually track the shock pulse movement after the striker hits the statically pressed waveguide against the loading medium, and at the same time to see the generation of the reflected deformation wave (the tail of the shock pulse) and its effect on the shock system elements and the loading medium. The results will make it possible to develop shock systems with the highest efficiency.

Most of the exoplanets with known masses at Earth-like distances to Sun-like stars are heavier than Jupiter, which raises the question of whether such planets are accompanied by detectable, possibly habitable moons. Here we simulate the accretion disks around super-Jovian planets and find that giant moons with masses similar to Mars can form. Our results suggest that the Galilean moons formed during the final stages of accretion onto Jupiter, when the circumjovian disk was sufficiently cool. In contrast to other studies, with our assumptions, we show that Jupiter was still feeding from the circumsolar disk and that its principal moons cannot have formed after the complete photoevaporation of the circumsolar nebula. To counteract the steady loss of moons into the planet due to type I migration, we propose that the water ice line around Jupiter and super-Jovian exoplanets acted as a migration trap for moons. Heat transitions, however, cross the disk during the gap opening within ≈10 4 years, which makes them inefficient as moon traps and indicates a fundamental difference between planet and moon formation. We find that icy moons larger than the smallest known exoplanet can form at about 15-30 Jupiter radii around super-Jovian planets. Their size implies detectability by the Kepler and PLATO space telescopes as well as by the European Extremely Large Telescope. Observations of such giant exomoons would be a novel gateway to understanding planet formation, as moons carry information about the accretion history of their planets.

ПОВЫШЕНИЕ ПРОЧНОСТИ СТАЛЕЙ 45, 40Х И 35ХГСА УПРОЧНЕНИЕМ ВОЛНОЙ ДЕФОРМАЦИИПредставлены данные о влиянии упрочнения волной деформации на прочность сталей 45, 40Х и 35 ХГСА. Для повышения прочности данных ста-лей предлагается в их поверхностном слое волной деформации создавать структурированные гетеро-генно упрочненные области, состоящие из чере-дующихся твердых и вязкопластичных участков.Ключевые слова: волна деформации, твер-дость, гетерогенно упрочненная структура, проч-ность.A.V. Kirichek, S.V. Barinov, A.V. Yashin STRENGTH INCREASE IN STEEL 45, 40H AND 35HGSA BY DEFORMATION WAVE STRENGTHENINGStrength increase by a deformation wave is more advantageous in comparison with other ways of strengthening as it allows ensuring in a surface layer a larger depth of strengthening with a smooth transition from a strengthened surface to an non-strengthened one which is especially significant for materials operating under conditions of static loading. The paper reports the fulfilled investigations of the impact of strengthening heterogeneity with a deformation wave upon strength of steel 45, 40H, 35HGSA. The investigations of strength properties were carried out both on samples strengthened only on one side (on contact one), and on samples strengthened on two sides (on contact and supporting ones). As a result of investigations it is defined that at one-sided treatment of steel 45 with strengthening uniformity increase a strength limit increased by 8%, the ductility decreased by 37%, an elastic limit increased by 43%. The strengthening uniformity increase in steel 40H resulted in strength limit increase by 13%, elasticity decrease by 38% and elasticity limit increase by 81%. At steel 35HGSA strengthening with uniformity increase there was observed a strength limit increase by 4.2%, plasticity decrease by 28% and elasticity limit increase by 51%. In case of two-sided strengthening with a deformation wave the values of strength properties of steel 40H did not actually change in comparison with one-sided treatment. The two-sided strengthening of samples made of steel 35HGSA brought to the growth of their strength limit by 2.8% and ductility limit by 20% as compared with one-sided treatment.