Structural changes in metastable austenitic steel during equal channel angular pressing and subsequent cyclic deformation

The paper reports a substantial improvement of the static and cyclic strength of a Cr-Ni-Ti austenitic stainless steel nanostructured by equal channel angular pressing (ECAP). After ECAP at room temperature or 673 K, the mean grain size decreased from 14 µm to 430 nm or 940 nm, respectively; corresponding ultimate tensile strength increased from 610 MPa to 1230 MPa or 940 MPa, and the fatigue limit increased from 275 MPa to 375 MPa or 475 MP

Damage buildup in Si under bombardment with MeV heavy atomic and molecular ions

Accumulation of structural disorder in Si bombarded at −196 °C with 0.5 MeV ²⁰⁹Bi₁ and 1 MeV ²⁰⁹Bi₂ ions (the so-called molecular effect) is studied by Rutherford backscattering/channeling spectrometry. Results show that the damage buildup is sigmodal even for such heavy-ion bombardment at liquid nitrogen temperature. This strongly suggests that, for the implant conditions of this study, the buildup of lattice damage cannot be considered as an accumulation of completely disordered regions. Instead, damage-dose curves are well described by a cascade-overlap model modified to take into account a catastrophic collapse of incompletely disordered regions into an amorphous phase after damage reaches some critical level. Results also show that Bi₂ ions produce more lattice damage than Bi₁ ions implanted to the same dose. The ratio of lattice disorder produced by Bi₂ and Bi₁ ions is 1.7 near the surface, decreases with depth, and finally becomes close to unity in the bulk defect peak region. Parameters of collision cascades obtained using ballistic calculations are in good agreement with experimental data. The molecular effect is attributed to a spatial overlap of (relatively dense) collision subcascades, which gives rise to (i) nonlinear energy spike processes and/or (ii) an increase in the defect clustering efficiency with an effective increase in the density of ion-beam-generated defects.Research at StPSTU was supported in part by the Ministry for General and Professional Education of the Russian Federation

Hot deformation and dynamic recrystallization of 18%mn twinning-induced plasticity steels

The deformation behavior of 18%Mn twinning-induced plasticity (TWIP) steels with 0.4%C or 0.6%C is studied by means of isothermal compression tests in the temperature range of 973-1373 K at the strain rates of 10³-10¹ s¹. The hot working is accompanied by the development of discontinuous dynamic recrystallization (DRX), which is commonly advanced by an increase in deformation temperature and/or a decrease in strain rate. A decrease in the carbon content promotes the DRX development, though the flow stresses scarcely depend on the carbon conten

Structure and texture evolution of the metastable austenitic steel during cold working

This work studies the structure and texture evolution in the 03Kh19N10 corrosion-resistant metastable metastable austenitic steel (0.05C-18.2Cr-8.8Ni-1.65Mn-0.43Si-0.05P-0.04S wt %, and Fe for balance) during cold rolling, which results in twinning and martensitic transformation. The strain-induced martensite nucleates heterogeneously in the microshear bands and at their intersection

Analysis of failings of walking paths design by the example of Academicheskiy district in Ekaterinburg

В статье исследуется состояние пешеходных связей строящегося райо на, выявлены ошибки проектировщиков в разработке пешеходной сети. В ходе исследования использованы методы фотовыявления, картографирования и автоэтнографии, которые помогли выявить причины нарушения газонных покрытий. Поднят вопрос несоответствия проектных решений текущим потребностям жителей района.The research of a condition of footpaths in the new district area is describing in the article. Designer’s failings in development of pedestrian network were described. During the research methods of photoidentification, mapping and auto-ethnography which have helped to establish causes of infringement of lawn coverings have been used. The question of discrepancy of design decisions to the current needs of residents of the area is brought up

The influence of ultrafine-grained structure on the mechanical properties and biocompatibility of austenitic stainless steels

In this study, equal-channel angular pressing (ECAP) of austenitic 316L and Cr-Ni-Ti stainless steels was carried out. Effect of ECAP at 400 °C on the evolution of the microstructure, mechanical properties, and biocompatibility of these steels was investigate

Comparative analysis of the legal status of testamentary foundations in Russia and foreign countries

Legal rules on a testamentary foundation are a novelty for Russian legislation. Since there were no analogues of this legal institution in Russia before, many law enforcement problems arise. Russian testamentary foundations have largely adopted the provisions on the foundations of the continental legal system. For a better understanding of the legal nature of this subject of law and solving law enforcement problems, it is necessary to analyze the legal status of testamentary foundations in the states where they have existed for a long time, and take into account the positive foreign experienc

Effect of pulsed magnetic field pre-treatment of AISI 52100 steel on the coefficient of sliding friction and wear in pin-on-disk tests

Disc specimens manufactured from commercial bearing rollers (AISI 52100 steel, 62–63 HRC) in initial state and after pre-treatment by pulsed magnetic field (PMF) with a magnetic field strength of 1–7 MA/m were tested with sunflower oil using pin-on-disk apparatus. According to the obtained results the treatment causes a reduction in the coefficient of friction and wear. To explain the results, nano- and microhardness tests as well as optical and atomic force microscopy were used. Reasons of the effect of PMF on the friction and wear were discussed.Peer reviewe

Microstructure and mechanical properties of AISi 304l austenitic stainless steel processed by various schedules of rolling

The paper studies various rolling schedules implemented at 500°С (incl. direct, reverse, and cross rolling) and their effect on the structure formation and mechanical properties in AISI 304L stainless steel samples. Both TEM and SEM research techniques were applied. An ultrafine grain-subgrain microstructure was found to be formed inside elongated original grains. Rolling-processed microstructural elements were close in their size with the minimum value observed after a reverse rolling (240 nm