Ultrasonic Technique for Assessment of the Rim Tightness of Hydro Generator Rotor

At the hydroelectric unit No. 11 of the Nizhnekamsk hydroelectric power plant, the filling wedges of a rotor were investigated by ultrasound in the free st     

Investigation of the influence of high hydrostatic pressure on the abrasive wear of hard-alloy materials

This paper outlines the results of an experimental study of the influence of high hydrostatic pressure on the abrasive wear of hard-alloy materials based on tungsten carbide (~90% WC ± 10% Co), as well as alloys based on iron with high contents of chromium. A specially developed setup has been described in the paper that makes it possible to test materials under the hydrostatic pressure of up to 250 MPa at different friction speeds. An investigation of the surfaces of samples using the Scanning Electron Microscopy method has revealed that the main damage of alloy surface occurs due to the delamination and spalling of hard particles. It has been revealed that the hydrostatic pressure significantly influences the wear rate of the investigated materials. When the pressure increases to 200 MPa, the wear of materials with high contents of chromium increases seven times, while for the material based on tungsten carbide, it increases twice.     

Ultrasonic and Eddy-Current Fatigue Monitoring of Austenitic Steel Welded Joints

Russian Journal of Nondestructive Testing - We investigated the process of fatigue damage in welded joints made of austenitic steel by ultrasonic and eddy current types of testing. The development...     

Erratum to: Ultrasonic and Eddy-Current Fatigue Monitoring of Austenitic Steel Welded Joints

Russian Journal of Nondestructive Testing - An Erratum to this paper has been published: https://doi.org/10.1134/S1061830921090126     

Calculation and Optimization of 3D Waveguiding System with Help of Integral Equation Method

For 3d waveguiding system calculations we used the Electric Field Integral Equation (EFIE) model, applied to infinitely thin, perfectly conducting waveguide surfaces. The solution represents induced current, from which the field in the device is obtained. With the help of this method an asymmetric mode converter TE01-TE11 was simulated and optimized for maximum efficiency. We have also studied a helically corrugated structure, which is used in pulse compressors, and analyzed the structures dispersion curves and compared it with measurement results.     

Use of Texture-Dependent Ultrasonic Parameter as Indicator of Degradation of Hot-Rolled Thin-Sheet Steel Under Uniaxial Tension

Journal of Nondestructive Evaluation - Centrifugal pumps (CPs) are mainly composed of impeller and bearings. The operation of the CPs is disturbed if any of its components is faulty. Bearings...     

Cusp Guns for Helical-Waveguide Gyro-TWTs of a High-Gain High-Power W-Band Amplifier Cascade

The evaluation, design, and simulations of two different electron guns generating the beams for W-band second cyclotron harmonic gyro-TWTs forming a high-gain powerful amplifier cascade are presented. The optimum configurations of the systems creating nearly axis-encircling electron beams having velocity pitch-factor up to 1.5, voltage/current of 40 kV/0.5 A, and 100 kV/13 A with acceptable velocity spreads have been found and are presented.     

The construction of ultimate strain diagrams for textured thin sheet materials taking into account their physical inhomogeneity

The paper presents results obtained in studying the influence of the inhomogeneity of mechanical property distribution over the surface of a thin sheet material on its ultimate strain. An algorithm for constructing ultimate strain diagrams for thin sheet materials is suggested. Data for calculating ultimate strain diagrams were obtained by the impact indentation and acoustic methods.     

Ultrasonic and eddy-current study of plastic deformation in austenitic-steel welds

The effect of plastic deformation of a 08Kh18N10T (analogue AISI321)-steel welded joint on electromagnetic and acoustic properties of the material has been studied by eddy-current and ultrasonic methods. It has been established that structural inhomogeneity in heat- affected zone leads to a nonuniform distribution of acoustic properties in the weld. The possibility for determining the plastic resource of material from ultrasonic data is demonstrated.