No 9 (2024)

In ultrasonic inspection of pipes of various diameters using antenna arrays and arrays, two technologies of reflector image reconstruction are widely used: antenna array focusing technology (PAUT) and digital aperture focusing (DAF) technology. If the tube diameter is larger than a hundred wavelengths, the DAF method can be used to reconstruct the reflector image by taking into account several reflections from the boundaries, assuming that the object of inspection is flat. In this case, the errors in the formation of DAF-image of reflectors will be insignificant. However, if the pipe diameter is several tens of wavelengths and the wall thickness is about half of the pipe diameter, then in this case the geometry of the inspection object must be taken into account to obtain a high-quality DAF-image of the reflectors. The paper considers the peculiarities of image formation at registration of echo signals by an antenna array or matrix, when scanning both on the external and internal surfaces of the object of control. In numerical and modeling experiments it is shown that both antenna array and antenna array can be used to obtain high-quality DAF-image of reflectors when scanning along the outer surface of a thick-walled pipe of small diameter. This is due to the presence of the effect of physical focusing of the ultrasonic field. But when scanning along the inner surface of a thick-walled tube of small diameter, because of the defocusing effect, it is necessary to register echoes with an antenna array to restore the image of reflectors.

A review of the types of defects in the production of corundum ceramic tiles and traditional methods of integrity testing of products made of this material is carried out. The integrity of tiles containing artificial defects was investigated by the method of active thermal testing using pulsed optical heating. A scheme of two-way thermal testing with software processing of the initial thermograms using the Parker method is applied. It has been established that the best results in detecting internal defects in ceramic tiles with a thickness of 10 mm during thermal stimulation using xenon lamps are obtained by the method of two-way thermal testing with the construction of thermal conductivity maps.

The results of studying the behavior of the magnetic characteristics of two-layer material containing layers of annealed sheet low-carbon Steel 15 and sheet metastable austenitic 12Kh18N9Т steel, subjected to cold rolling with a compression of 50 %, under biaxial symmetric tension have been presented. Experiments on biaxial deformation were carried out on the original biaxial testing machine, allowed to determine the physical properties of materials during elastic-plastic deformation independently along two axes. It has been shown that the coercive force of the studied two-layer material vary monotonically over the entire range of elastic-plastic biaxial deformation and can be used as an informative parameter for assessing the it’s stresses and deformations.

For detecting substances with similar chemical composition and density, one of the promising methods of non-destructive testing is dual-energy processing of X-ray images. In particular, dual-energy transformation algorithms can be used to search for minerals hidden within barren rock. This method is most effective when the conditions for registering X-ray images and energy levels are properly selected. This study compares the effectiveness of image processing using the dual-energy method for three cases of spectral composition variation: firstly, as a result of adjusting the voltage on the X-ray tube; secondly, by attenuating low-energy radiation through the use of a copper filter; and thirdly, by combining these two methods. Beryl particles embedded in ground muscovite are used as samples for detection. The study utilizes a pulsed X-ray radiation source that generates radiation pulses of nanosecond duration. An original high-voltage generator scheme has been implemented for the method of regulating radiation energy by changing the peak voltage on the X-ray tube. The use of X-ray sources of this type enables the acquisition of high-resolution X-ray images of moving objects.

Cyclic bending testing of austenitic chromium-nickel steel grade 10Kh18N10T samples was carried out. Evalution of relative magnetic permeability showed its noticeable increase when the samples became fractured. This increase is related to deformation martensite appearance. Additional experiment showed, that deformation martensite formation starts before the actual destruction of the sample.

The paper discusses methods for optimizing magnetizing systems of portable flaw detectors for drill pipes, the main purpose of which is to reduce weight, reduce energy consumption and create a more uniform magnetic field in the working area. The disadvantages of traditionally used systems are outlined and three ways to improve them are proposed.

The article presents an analysis of the formation possibility through defects in a gas pipeline as a result of short-term exposure to an arc discharge. The results of metallography, electron microscopy, elemental analysis, as well as the modeling results, confirming the formation possibility through defects in a 7 mm thick gas pipeline wall during an exposure to an arc discharge of less than 2 seconds are presented.