Effect of a magnetic field on the reverse and forward martensitic transformations in the Fe-33% Ni alloy

Effect of a magnetic field on the reverse and forward martensitic transformation in an iron-nickel alloy with the temperature of the start of the α-γ transformation that is close to the Curie temperature of the γ phase has been studied. The result obtained is explained by the mutual compensation of two mechanisms of the effect of a magnetic field on the reverse martensitic transformation in this alloy. The role played by the magnetic state of austenite in the realization of the corresponding kinetics of the martensitic transformation in the iron-based alloys with a mixed kinetics is discussed.     

Investigation of the influence of high temperatures and pressure on electric durability of polymethylsyloxane liquid PMS-20 and castor oil saturated by elegas

The results of investigations of the influence of high temperatures and pressure on the electric strength of polymethylsyloxane liquid PMS-20 and castor oil saturated by elegas (SF₆) are presented. The research data can be applied to the design of electrotechnical devices, specifically high-voltage pulse capacitors Published by way of discussion.     

Long-term strength of coke-furnace heating walls

A hierarchical model of material with a minimum number of implicit parameters has previously been proposed. This model permits calculation of the long-term strength of the heating walls in coke furnaces, as well as assessment of their condition. As an example, three long-term strength curves are presented for Dinas brick at 1273, 1323, and 1373 K. These curves are based on the equation of state and the kinetic equations containing the minimum number of implicit parameters.     

Crystal structure of the new ternary aluminide CeRu3−xAl10+x (x = 0.17)

A large and transparent Yb³⁺:GdYCOB crystal with dimensions up to 30 mm× 58 mm have been grown by the Czochralski method. The spectral properties of Yb³⁺:GdYCOB crystal has been investigated. The absorption cross-section (σ_a) is 1.65 × 10⁻²⁰ cm² at 977 nm. The emission cross-section (σ_e) is 0.25 × 10⁻²⁰ cm² with an FWHM of 37.2 nm at 1020 nm. The fluorescence lifetime is 3.00 ms.     

Chemical processes during the heat treatment of basalt fibers

It has been established that, during the heat treatment of an unsubmixed (unsub-blended) glass (with the contents of Ca and Mg, corresponding to the natural basalt) at the first stage of the oxidation process, magnetic nanoparticles (>20 nm according to the transmission electron microscopy data) of (Mg, Fe)₃O₄ are formed in a nonmagnetic glassy matrix (that is, the oxidation proceeds as internal reaction), followed by the crystallization of alumosilicate phases. In the glasses enriched in CaO, such a crystallization occurs simultaneously with the evolution of the spinel phase. An analysis of the distribution of cations over the fiber cross section has demonstrated that annealing under oxidative conditions is conductive to an increase at the surface of fibers in the concentration of Ca in the case of utilizing an unsubmixed material and that of Na in the case of the glass with a higher content of CaO. The long-term annealing of the nanocomposite at the temperatures of its production results (according to the measurement data of magnetic properties) in the interaction of a part of the formed (Mg, Fe)₃O₄ with the alumosilicate matrix. Original Russian Text ? A.V. Knot’ko, A.V. Garshev, I.V. Davydova, V.I. Putlyaev, V.K. Ivanov, Yu.D. Tret’yakov, 2007, published in Korroziya: Materialy, Zashchita, 2007, No. 3, pp. 37–42.     

Optimizing the Parameters of Ultrasonic Surface Plastic Deformation by a Free Steel Indenter

Russian Engineering Research - The influence of ultrasonic surface plastic deformation on the surface roughness and hardness is considered. The influence of the force applied to the deforming...     

Modelling Acoustic–Electric Nondestructive Testing for Defects in Dielectric Materials

Russian Journal of Nondestructive Testing - The influence of defectiveness of solid-state dielectric samples on the parameters of the electromagnetic response under deterministic acoustic action on...     

Effect of laser microalloying with niobium on the wear resistance of stainless steels

We have studied the effect of laser alloying of 20Kh13 and 12Kh18N10T steels with niobium on their physicochemical properties. Microalloyed surface layers of thickness more than 350 μm, enriched with niobium, carbon, and oxygen in the solid solution and separate oxycarbide inclusions, were formed by means of laser treatment. The microhardness of the external layers of steels becomes 2–3 times higher (up to 7.1–7.7 GPa). Laser alloying reduces the wear of 20Kh13 steel by a factor of 5–6 under a contact pressure of 0.29 MPa and cuts it in half under 0.42 MPa. The wear of 12Kh18N10T steel is reduced by a factor of 2–3. We have also proposed a scheme of the wear of steels, according to which their wear resistance increases owing to the formation of hardened surface layers, where the oxycarbide inclusions exert a reinforcing action on the more plastic solid solution of niobium, carbon, and oxygen in iron.