Using the method of scanning microscopy in the mode of electron backscatter diffraction (EBSD), the structural and textural states of two medium-carbon alloy steels near the joint obtained by ...rotational friction welding are investigated. In both steels, martensitic structures are detected in the zone of thermal deformation influence, which is characterized by the presence of a pronounced crystallographic texture close to that of the (110)001 plane with the axis normal to the surface of the joint. Assuming the formation of new phase nuclei at special boundaries Ʃ3, the formation of a practically one-component crystallographic texture is explained by shear transformation of deformed austenite in accordance with multivariate orientation relations of the Kurdyumov–Zaks type.
We studied the effect of sulfated glycosaminoglycan on the infection properties of high-virulence Dal’negorsk strain and low-virulence Primorye-437 of tick-borne encephalitis virus. Differences in ...reproductive activity of these strains and their tropism to the target cells were revealed. Glycosaminoglycan reduced pathogenetic activity of high-virulence strain
in vitro
, but had no effect on low-virulence strain. The interaction of imperfect virus particles of non-pathogen strain with the glycosaminoglycan led to their accumulation in cell, but in the culture medium of SPEV cells infected with experimental and control samples, accumulation of virus particles did not differ. The results on activity of glycosaminoglycan binding with strains differing by their biological and molecular genetic characteristics can be used to assess their pathogenic potential.
To date, a lot of data on molecular genetic characteristics of different tick-borne encephalitis virus strains has appeared. Only on the basis of the E protein genome, sequences of about 1,500 TBEV ...strains were registered in GenBank.
The purpose of the work - revision and comparative analysis of data on complete genomes sequences of the Far Eastern subtype of TBE virus strains distributed in the Asian part of Eurasian continent.
The data on the complete genomes of 84 strains of TBEV isolated in Asia were used; phylogenetic analysis was performed.
it was shown that variants of the TBEV of the Far Eastern subtype are circulating here and form three separate clusters (Sofjin, Senzhang- и Shkotovo-like strains). Sofjin strain (Sofjin-1953, Sofjin-Chumakov, Sofjin-KSY) was considered to be the reference for Far Eastern TBE virus subtype strains and a cluster of Sofjin-like strains. Sofjin-like strains were not found in China and Japan, but widely distributed throughout the area of Primorsky and Khabarovsk krai. The group of Senzhang-like strains was distributed in China, Eastern Siberia, Khabarovsk krai and northern Primorsky krai, but was not found in Japan (Hokkaido). According to molecular genetic characteristics the youngest and more genetically homogeneous group was the Shkotovo-like strains, isolated in the southern part of Primorsky krai, however not found on Hokkaido Island (Japan).
revision of the complete genome characteristics of TBEV strains revealed the features of micro-evolutionary process of viral populations in the Asian part of Eurasia, show the individual affection of strains to certain territories, as well as detect random finds of such strains in the territories of other natural foci.
•Based on the thermodynamic modeling, the hardening phases in equilibrium and composition of the each phase were obtained.•Two stages of the carbides growth were examined.•Results of modeling are ...consistent with electron microscopic data.
Thermodynamic and kinetic modeling was performed to determine the kinetics of the carbides growth in the low alloyed steels of 15Cr2NiMoV type after heat treatment.
Two stages of the carbides growth were examined: diffusion growth within the framework of Ham model and coalescence (coagulation) in the context of Lifshitz-Slyozov-Wagner (LSW) model.
The results of modeling are consistent with the data of transmission electron microscopy.
We develop mathematical models used to describe the dependences of the critical pitting temperatures of AISI 321 steel in model circulating waters with pH 4–8 and a concentration of chlorides varying ...within the range 350–600 mg/liter on its chemical composition and structure. These models are based on multidimensional linear regressions of the first order and neural networks with forward signal propagation. By using the developed mathematical models, it is established that the critical pitting temperatures of AISI 321 steel become higher as the pH value of the circulating water, the mean distance between oxides in the steel, and the contents of manganese and chromium increase and as the mean grain diameter of austenite and the content of chlorides in the medium decrease. At the same time, it is shown that the influence of the medium is most pronounced but the heterogeneity of steel, which depends on the contents of Cr, Si, Mn, and N, also strongly affects its pitting resistance. It is proposed to use the developed mathematical models for the choice of the optimal heats of AISI 321 steel guaranteeing its highest pitting resistance in model circulating waters.
The temperatures of appearance and degradation of short-range and long-range ordering in VDM® Alloy C-4 (UNS 2.4610/N06455) are determined with the help of physical methods of research. The ...sensitivity of the methods to these effects is studied. The results obtained are used to make recommendations on determination of the temperatures of disordering-ordering and ordering-disordering transitions in alloys of the Ni – Cr – Mo system.
The relation between the microstructure and the corrosion behavior of Hastelloy® G-35® in a KCl – AlCl
3
salt solution after different deformation and heat treatments (DHT) is studied. It is shown ...that DHT may be used for creating a structure providing a corrosion rate lower than that of the traditional single-phase structure formed in the alloy by quenching.
The object of the study was 316L steel obtained by the method of selective laser melting (SLM). The structure of 316L steel was investigated after different SLM modes. The effect of different SLM ...modes on the second phases precipitation after heat treatment was studied. It is revealed that the fraction of precipitates of the χ-phase correlates with the energy density of the laser beam during SLM.
The electrochemical extraction of the second phase in the VDM® alloy C-4 alloy has been studied by transmission and scanning microscopy, as well as by X-ray phase analysis. It was found that ...annealing, which consists in heating up to 850 °C with further holding for 32 hours and cooling in a furnace, leads to the precipitation of a second phase in VDM® alloy C-4 alloy. It can lead to embrittlement and a general decrease in the corrosion resistance of the alloy. The precipitation of the anode deposit (the second phase in the samples of the VDM® alloy C-4 alloy after annealing) and its identification was carried out by the methods indicated above.
The corrosion behavior of austenitic steels AISI 316L (analog of 03Kh16N15M3), 12Kh18N10T (analog of AISI 321) and 06KhN28MDT and ferritic and ferritic–martensitic steels 12Kh13 (analog of AISI 410), ...08Kh17T (analog of AISI 439), and 16Kh12MVSFBR is studied in chloroaluminate melts at a temperature of 550°C. The corrosion rates of these steels in a KCl–AlCl
3
electrolyte are determined. The corrosion damage of the stainless steel surfaces is shown to have a continuous inhomogeneous character and to be characterized by etching off the most electronegative elements, namely, chromium, iron, and manganese.
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