Criteria for the evaluation of the technical state of the long-lived metal of HPP equipment based on acoustic structuroscopy

Abstract

The criteria for the maintenance evaluation of long lived metal of the equipment of heat power plants during the acoustic structuroscopy of weld joints of vapor pipelines and boiler drums are described. The data on the change of the structural state of metal during long term operation of heat resistant steels are given. The dependences of the criteria versus the values of local fields of internal stresses of a crystal lattice are given. The relationship between the integrated criterion and the durabil ity of heat resistant steels is presented.

The correlation between acoustic and magnetic properties in the long working metal boiler drum with the parameters of the electron microscope

“…These quantitative characteristics of the structure are shown and described by the authors in [5,8,10,12]. It has been found that the most serious changes occur in the fracture zone and the heat affected zone (HAZ) in welding.…”

Structural-Phase State, Mechanical Properties, Acoustic and Magnetic Characteristics in the Sustainable Deformation Localization Zones of Power Equipment Made of Structural and Heat Resistant Steels

“…The samples before and after plastic deformation were tested by non-destructive methods: spectral-acoustic (measuring and computing complex "ASTRON" (designed to measure acoustic characteristics with Rayleigh waves) [20,26]) and magneto-noise methods (structure and stress analyzer "Introscan" (NPF Diagnostics LLC, Belarus) (designed to assess the magnitude of the intensity of magnetic noise) [26]). At the same time, such characteristics as the delay time and velocity of surface acoustic waves, the attenuation coefficient, the amplitude of the received signal, and the intensity of magnetic noise were determined (Figures 1-3).…”

“…Currently, control methods are being developed and implemented, the measured characteristics of which are sensitive to changes in structure and mechanical characteristics. One of these methods is the spectral-acoustic control method [20][21][22][23]26].…”

“…Increasing the reliability and accuracy of the assessment is impossible without analyzing the structural-phase state and mechanical characteristics of the metal of long-term power equipment. The detection of a characteristic pre-fracture zone or zone of localization of deformations is an important aspect [26]. One of the main advantages of this approach is the fundamental possibility of detecting the site of future destruction of the sample long before necking.…”

Investigation of Biaxial Stress State in R65 Rails by Acoustoelasticity Method

“…Задача продления срока службы рельсов является актуальной и требует создания новых методик выявления внутренних напряжений, возникающих при их изготовлении и в эксплуатации и влияющих на долговечность. Значительное число работ посвящено оценке технического и напряженного состояния в металлоконструкциях и в том числе рельсах экспериментальными и теоре-тическими методами [4][5][6][7][8][9][10][11][12][13]. Использование теории акустоупругости и возможностей возбуждения и приема упругих волн позволяет исследовать напряженное состояние в самых разнообразных металлоконструкциях, включая конструкции со сложным профилем, таких как рельсы [14][15][16][17][18][19].…”