Igor Nikolaevich has educated about thirty candidates and doctors of sciences. His students scattered all over the former USSR, and there are them in Europe. And his theory of the acoustic path has made its way without exaggeration all over the world. This book is a tribute of love and respect to a great scientist and a wonderful person.
The general principles of construction are described and the features of methods of automated ultrasonic inspection of welded joints using systems with coherent processing using the methodology of synthesized aperture are analyzed. The features of the application of devices using digital SAFT and CFA processing (SAFT and CFA flaw detectors) and devices with headlights (HEADLIGHT flaw detectors) are analyzed. A common characteristic of flaw detectors is to obtain a high-resolution image of the controlled volume of the product. The actual parameters of the detected discontinuities are estimated from these images. The methods of AUZK developed by LLC "SPC thr ECHOPLUS, which allow using the useful features of SAFT, FAR and CFA flaw detectors, are considered. All control methods are divided into two groups: control of pearlitic welded joints and welded joints with a high level of structural noise. The features of the development of methods depending on the object of control are considered. Examples of practical use of techniques are given. Their main characteristics are given, such as: operating frequency, methods of coherent data processing, resolution and measurement error of real dimensions, etc.
Quantitative assessment of the reliability of non–destructive testing systems is an important factor in a risk-based approach to diagnostics. For this purpose, defect detection curves (PoD curves) and confidence curves (ROC curves) are usually used for non–destructive testing (NC). The PoD (Probability of Detection) curve describes the probability distribution of detecting defects by their size. This curve reflects the capabilities of the used method and monitoring equipment on the selected sensitivity of the system and allows you to predict the detectability of defects of various sizes in the object due to the known functional dependence of the probability of detecting defects on their size.
To assess the reliability of the data obtained during the control of an object using methods and means of ultrasonic inspection (ultrasound), it is necessary to take into account not only the probability of detecting defects during control, but also the probability of their skipping and fixing false defects. For these purposes, ROC diagrams and ROC curves (Receiver Operating Characteristic curve) are often used, which reflect the mutual dependence of the number of false and correctly found defects. The actions performed for their structure are called ROC analysis. ROC analysis was developed and applied in the theory of signal processing and radar to describe the relationship between events of correct target detection and false positives. In non–destructive testing, ROC analysis began to be used to analyze the reliability of the control of techniques, equipment and personnel as a means for a quick assessment of methods and devices of ultrasonic testing. Below we will consider the features of the application of ROC analysis for ultrasonic flaw detection and ultrasonic flaw detection devices. To do this, we use a database of UZK obtained on austenitic annular welded joints (SS) containing cracks of various heights. The measurements were performed using two methods of ultrasonic flaw detection (FAR and SAFT processing), in which the analysis of control data was performed using acoustic focused images, and the traditional method of ultrasonic flaw detection, in which the analysis of control data was performed by the amplitude of the ultrasonic signal.
To control the thickness of pipelines with non-equidistant surfaces (for cone junctions with a large thickness difference and for the area under the weld reinforcement roller), a technology for constructing a bottom surface profile based on the ultrasonic method using digital antenna focusing (CFA) has been developed. The method is based on the emission of ultrasonic waves in the OK and the registration of these ultrasonic waves reflected from the internal boundaries of the OK, as well as subsequent digital processing of the CFA with the formation of images from the recorded signals.
The article deals with the application of automated ultrasonic inspection of austenitic welded joints, performed instead of radiographic control carried out during the installation of technological pipelines of the catalytic cracking complex. The results of tests of the automated ultrasonic inspection of austenitic welded joints based on the use of coherent methods for obtaining acoustic images of the internal structure of the object of control are presented.
The control of welded joints in the main shut-off valves of the first circuit of the VVER-440 reactor plant (GPP) is difficult due to the high level of structural noise and the need to use pulses reflected once from the inclined bottom of the branch pipe. Carrying out the control on the longitudinal wave leads to the appearance in the reconstructed image of the reflectors of false glare formed by pulses on the transverse wave. Since the amplitude of false glare can be commensurate with the amplitude of glare obtained on longitudinal waves, the analysis of such images can be difficult. To improve the image quality, it is proposed to register echo signals using thinned antenna arrays and apply three-dimensional processing of echo signals. Numerical and model experiments have shown that this approach increases the frontal resolution in the additional plane several times and reduces the amplitude of false glare, which makes it possible to increase the sensitivity and reliability of expert ultrasonic control of the main gate valve.
The collection includes the most interesting works performed by the ECHOPLUS team in recent years. Simultaneously with the development and use of automated ultrasound systems with coherent data processing, the following are presented works devoted to the research, development and application of devices with phased array antennas. New electronics, scanning systems, and image quality improvement algorithms are described. The basic principles of building control techniques using such systems are considered. The question of the ratio of radiography and ultrasound in non-destructive testing is investigated. It has been shown that coherent automated ultrasonic inspection in some cases gives results no worse, and in combination better, than radiography. The experience of using a computer programming program is given modeling the tasks of the "CIVA" ultrasound inspection center for the development of ultrasound control techniques.
The collection includes the most interesting works performed by the team of the ECHOPLUS in recent years. Simultaneously with the development and use of automated ultrasound systems with coherent data processing, the following are presented works devoted to the research, development and application of devices with phased antenna arrays. New electronics, scanning systems, and image quality improvement algorithms are described. The basic principles of the construction of control methods using such systems are considered. The question of the ratio of radiography and ultrasound in non-destructive testing is investigated. It is shown that coherent automated ultrasonic inspection in some cases gives results no worse, and in combination better, than radiography. The experience of using a computer programming program is given. modeling of tasks of the "CIVA" ultrasound control center for the development of ultrasound control techniques.
The report considers the possibility of switching from the old criteria for assessing the quality of welded joints, such as equivalent area, number of point defects, conditional dimensions, etc., to new information criteria for defects based on the results of modern types of automated ultrasonic testing. Three-dimensional visualization of control areas obtained using modern coherent image reconstruction methods provides new information parameters. Such parameters can be the overall dimensions of defects, the profile of the inner surface of the seam, as well as a visual, close to optical, image of the defect obtained by using many sounding schemes using digital focusing technology of antenna arrays. Examples of existing methods with dimensional criteria according to the new standards of quality assessment are given.
The results of the certification of the continuous thickness measurement technique of NPP pipelines are presented. The description of the equipment used with the support of FR and EMAP technology is given. To measure the thickness of straight sections, cone junctions and bends with 100% data recording, FR flaw detectors such as AUGUR ART, Omniscan, Harfang, Gecko with two-coordinate scanning devices are used. To measure the profile under the weld reinforcement roller, the TOFD method is used, implemented using phased arrays.