Usage of Volumetric Reflectors for Adjusting Ultrasonic Testing Parameters

In ultrasonic flaw detection, lateral cylindrical drillings are traditionally used to adjust and check the parameters of equipment. Other volumetric reflectors, such as vertical drillings or spherical pores, are rarely used. This article notes that such models of internal and surface defects of welded seams are convenient to use and easy to manufacture. For a long time, a limitation to the use of drillings for modeling in ultrasonic flaw detection was the use of these effects not only on defect models in the form of noise associated with the diffraction effects of elastic waves running around cylindrical cavities. It is noted that these effects are currently well studied and are used to identify the type of defects and measure their sizes. Based on the results of experiments on observing the scattering of longitudinal waves and transverse waves with different polarization on cylinders and spheres, typical examples of the manifestation and use of these diffraction effects are given. The expediency of using not only drillings, but also spherical pores is noted. Experiments of the ultrasonic waves scattering on pores are performed on transparent glass samples for clarity. Comparative data on the manifestation of diffraction effects on various volume cavities are presented. In particular, it is noted that there is a focusing of signals enveloping spherical pores. Limitations on the duration of ultrasonic wave pulses are noted, at which diffraction signals can be used to increase the information content when detecting defects. It is recommended to expand the use of 2 mm diameter side drillings in samples to adjust sensitivity during ultrasonic testing using the echo method.