Influence of a lead melt on plastic deformation of high-alloyed heat-resistant steels

The effect of liquid-metal embrittlement in lead melt is typical of Kh12MVSFBR ferrite-martensitic steel and is observed in the temperature range of 300 – 500°C at a deformation rate of 8 · 10^–4 sec^–1. The maximum decrease in the plasticity of tempered specimens occurs at a temperature of 450°C. A decrease in the amount of -ferrite in the composition (martensite hardening without high-temperature annealing) results in a substantial decrease in plasticity and in broadening of the temperature range of embrittlement. 08Kh16N11S3MB austenitic steel is not affected by liquid metal embrittlement in the investigated temperature range for the deformation rates under consideration.Karpenko Physicomechanical Institute, Ukrainian Academy of Sciences, L'viv. Translated from Fiziko-Khimicheskaya Mekhanika Materialov, Vol. 30, No. 4, pp. 71–76, July – August, 1994.     

Corrosion-Mechanical Strength of Structural Materials in Contact with Liquid Lead

Corrosion-mechanical tests of 10Kh15N9S3B and 10Kh9NSMFB steel samples in liquid lead at 360–550°C have shown that the long-time strength in lead flow decreases at short times to fracture and converges to the results of tests performed in air at about 10000 h. No liquid-metal embrittlement of 10Kh15N9C3B steel is observed. 10Kh9NSMFB steel becomes brittle in the hardened state. Embrittlement intensifies in notched samples. The low-cycle fatigue strength is correlated with a change in ductility with short-time fracture. No decrease of fracture toughness of 10Kh9NSMFB steel with a fatigue crack was observed in tests in liquid lead.     

Local Lattice Dynamics in the Mg0.5Al0.5B2 Superconductor

We have studied temperature evolution of the local as well as the average crystal structure of MgB₂ and Mg_0.5Al_0.5B₂ using real-space atomic pair distribution function (PDF) measured by high resolution neutron powder diffraction in a wide temperature range of T=10–600 K. The mean square relative displacements (MSRD) of atomic B–B, B–Mg (B–Al) pairs are compared with mean-square displacements (MSD) to calculate atomic correlations. In spite of the enhanced atomic disorder in Mg_0.5Al_0.5B₂, where the boron–boron, and boron–magnesium pair motions are found to be small, we find that the same atomic correlations in MgB₂ assume even slightly lower values and remain nearly constant in a wide temperature range of 0–600 K. This anomalous behavior and its physical interpretation provoke new questions on our understanding to the local lattice dynamics in this material.     

Formation and investigation of nitride fuel compatible protective coatings on ferrite–martensite steel

A method for spontaneous formation of a protective coating, consisting of zirconium nitride in a eutectic based on lead with 2.25 mass % magnesium and 0.2 mass % zirconium, on a steel surface is proposed for decreasing the interaction between the sublayer in a fuel element and the fuel-element cladding. It is confirmed on the basis of gravimetric analysis, analysis with a deuteron beam from an EG-2.5 accelerator, x-ray diffraction analysis performed with a DRON-1 diffractometer, and x-ray spectral wave microanalysis that at temperatures in the range 813–1023 K a zirconium nitride coating on the surface of 16Kh12VMSFBR steel will effectively increase the service life of the fuel assemblies in the BREST-OD-300 system (35000 h). The maximum mass loss will be 0.12 kg/m² and the maximum thinning a fuel-element wall will be 15  μm. Translated from Atomnaya énergiya, Vol. 105, No. 5, pp. 269–274, November, 2008.     

Iron chalcogenide superconductors at high magnetic fields

Iron chalcogenide superconductors have become one of the most investigated superconducting materials in recent years due to high upper critical fields, competing interactions and complex electronic and magnetic phase diagrams. The structural complexity, defects and atomic site occupancies significantly affect the normal and superconducting states in these compounds. In this work we review the vortex behavior, critical current density and high magnetic field pair-breaking mechanism in iron chalcogenide superconductors. We also point to relevant structural features and normal-state properties.     

Color reproduction on varnished cardboard packaging by using lower ink coverages due to the gray component replacement image processing

Even in these challenging times, cardboard packaging industry is increasing its revenue with stable annual increase prediction, but customers are increasing demands on the packaging with respect to environmental protection, attractiveness, and branding. This article aims to determine the influence of image processing in terms of gray component replacement and overprint varnishing on the color reproduction on a cardboard packaging material. A test chart with tertiary colors was defined and modified by different gray component replacement levels. It was printed in accordance with ISO norm on coated and uncoated cardboard and finished by overprinting water based, offset, and UV varnish. The prepared samples were evaluated by measuring surface coverage, tone value increase (dot gain) of primary colors and calculating ΔE₀₀ of defined tertiary colors. The results showed that gray component replacement application reduces ink consumption. Higher gray component replacement applied results in lower ink surface coverage, but the decrease is also dependent on the image content. The TVI (dot gain) is significantly influenced only by applying UV varnish, resulting with higher TVI. The color differences of the tertiary colors showed that increased level of the gray component replacement applied did not cause significant color differences, even decreased color difference in some cases. Additionally, applying gray component replacement decreased color differences in “reddish” part of the gamut. This research proved that lowering the ink consumption due to the gray component replacement will not cause significant differences in the color reproduction. Furthermore, varnishing with commercial offset or water-based varnish will not cause higher deviations in color reproduction, but use of the UV varnish would.     

Phenolics as antioxidants in garlic (Allium sativum L., Alliaceae)

The antioxidant activities of polar fractions of mature garlic bulbs and immature plants in four different model systems are presented. Antioxidant activity was evaluated as free radical-scavenging capacity (RSC), together with the effect on lipid peroxidation (LP). RSC was assessed by measuring the scavenging activity of garlic extracts on 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydrogen peroxide. Effects on LP were evaluated by following the activities of examined garlic extracts in Fe²⁺/ascorbate and Fe²⁺/H₂O₂ systems of induction. Investigated extracts reduced the DPPH radical formation (IC₅₀ ranging from 1.03 to 6.01 mg/ml) and neutralised H₂O₂ (IC₅₀ ranging from 0.55 to 2.01 mg/ml) in a dose-dependent manner. Strong inhibition of LP in both systems of induction was observed for all tested garlic extracts. Various levels of phenolics (0.05–0.98 mg gallic acid equivalents/g of dry extract) and flavonoid aglycones (4.16–6.99 μg quercetin equivalents/g of dry extract) in the investigated extracts of garlic could explain the obtained differences in these results only partially.