10.14489/td.2021.09.pp.004-015

2021, 09 September

DOI: 10.14489/td.2021.09.pp.004-015

Danilov V. N., Voronkova L. V.
ON THE INFLUENCE OF THE SIZE OF FLAKE GRAPHITE INCLUSIONS AND ITS VOLUME CONTENT ON THE ACOUSTIC PARAMETERS OF CAST IRON AND THE CHARACTERISTICS OF ULTRASONIC LONGITUDINAL WAVE SIGNALS
(pp. 4-15)

Abstract. Algorithms have been presented for calculating the velocity (in the approximation of a fine-layered model) and the attenuation coefficient of a longitudinal ultrasonic wave in cast iron, depending on the average size of graphite elements and its volume content, the calculation results for which are qualitatively confirmed experimentally. The calculation was performed using a fine-layered model of the structure, the graphite inclusions were described in the form of plane-parallel layers placed in an isotropic elastic medium (metal base). Computer simulation of acoustic paths for a mediumcast iron with flake graphite for standard direct converters is carried out in order to study the influence of such a medium on the characteristics of transmitted and received signals during ultrasonic testing. In the course of the research, a previously developed model was used to calculate the attenuation coefficient of longitudinal waves in cast iron with flake graphite due to their Rayleigh and phase scattering on graphite inclusions. Computer simulation of the acoustic characteristics of the signals of a direct linear probe with a phased array in cast iron with flake graphite was carried out, during which the shape of the acoustic pulses of the longitudinal wave was calculated, depending on the distance traveled by the wave and the value of the attenuation coefficient for various models of cast iron. The main modeled characteristics of the transducer include the directivity characteristic and the change in the signal amplitude along the acoustic axis. It is shown that for cast iron with flake graphite, there are cases when the directivity of the probe with a phased array transmitted into the cast iron is practically absent.

Keywords: cast iron, flake graphite, inclusion, longitudinal wave, signal spectrum, attenuation coefficient, direct probe, phased array, directivity characteristic, focusing distance.

+ - About the Authors Click to collapse

V. N. Danilov, L. V. Voronkova (ROSATOM Scientific Centre of Russian Federation JSC RPA “CNIITMASH”, Moscow, Russia) E-mail: Данный адрес e-mail защищен от спам-ботов, Вам необходимо включить Javascript для его просмотра. , Данный адрес e-mail защищен от спам-ботов, Вам необходимо включить Javascript для его просмотра.

+ - References Click to collapse

1. Cast iron with lamellar graphite. Stamps. (2004). Ru Standard No. GOST 1412–85. Moscow: Izdatel'stvo standartov. [in Russian language]
2. Mining equipment. Cast iron tubing. Tubing ring sets. General technical conditions. (2016). Ru Standard No. GOST R 57054–2016. Moscow: Standartinform. [in Russian language]
3. Engineering handbook. Dpva.ru tables. Available at: https://dpva.ru [in Russian language]
4. Merkulova V. M. (1972). Influence of microcracks on the acoustic parameters of the medium. Defektoskopiya, (5), pp. 51 – 55. [in Russian language]
5. Danilov V. N. (2009). On some features of the echo signal from flat reflectors in the far zone of the combined direct transducer. Defektoskopiya, (5), pp. 3 – 17. [in Russian language]
6. Heine H. J. (1975). Using NDT Effectively – Ultrasonics. Foundry M and T.
7. Zbinden H. U. (1969). Der ultrashall als Mittel der Wer Kstafforschung. Technica, 14, pp. 3 – 18.
8. Himchenko N. V. (1976). Ultrasonic structural analysis of metallic materials and products. Moscow: Mashinostroenie. [in Russian language]
9. Yablonik L. M. (1960). The use of ultrasonic flaw detection for testing gray cast iron products on an untreated surface. Leningrad House of Scientific and Technical Propaganda. [in Russian language]
10. Danilov V. N., Voronkova L. V. (2019). Investigation of the influence of attenuation of elastic longitudinal waves in lamellar graphite cast iron on the characteristics of signals during ultrasonic testing. Kontrol'. Diagnostika, (6), pp. 18 – 33. [in Russian language] DOI: 10.14489/ td.2019.06.pp.018-033
11. Cast iron castings with various shapes of graphite. Methods for determining the structure. (2005). Interstate standard No. GOST 3443–87. Moscow: Izdatel'stvo standartov. [in Russian language]
12. Merkulov L. G., Merkulova V. M. (1976). Lectures on the physics of ultrasound. Taganrog: TRTI. [in Russian language]
13. Danilov V. N. (1989). Calculation of the damping coefficient of elastic waves for scattering in polycrystalline media. Defektoskopiya, (8), pp. 17 – 23. [in Russian language]
14. Ermolov I. N., Lange Yu. V. (2006). Ultrasonic testing. Non-destructive testing: handbook: in 8 volumes, 2nd ed. Vol. 3. Moscow: Mashinostroenie. [in Russian language]
15. Ermolov I. N. (1992). Ultrasound control: a short handbook. Moscow: NPO TsNIITMASh. [in Russian language]
16. Voronkova L. V. (2006). Ultrasonic inspection of cast iron castings. Moscow: Izdatel'stvo MGTU im. N. E. Baumana. [in Russian language]
17. Danilov V. N. (2009). Calculation of the acoustic field of an oblique transducer in the far zone. Defektoskopiya, (12), pp. 36 – 51. [in Russian language]
18. Danilov V. N. (2006). Program for computer simulation of the operation of electroacoustic paths of flaw detectors "Impulse +". Defektoskopiya, (3), pp. 37 – 43. [in Russian language]
19. Voronkova L. V., Danilov V. N. (2019). Modeling the influence of attenuation of ultrasonic longitudinal waves in cast iron with lamellar graphite on the characteristics of pulse signals. NDT Days, Vol. 2, (3), pp. 269 – 277. [in Russian language]
20. Danilov V. N., Voronkova L. V. (2020). Some features of ultrasonic testing of objects made of lamellar and nodular cast iron using direct linear transducers with phased arrays. Kontrol'. Diagnostika, Vol. 23, (3), pp. 4 – 19. [in Russian language] DOI: 10.14489/td.2020.03.pp.004-019

+ - Purchase digital version of a single article Click to collapse

This article is available in electronic format (PDF).

The cost of a single article is 450 rubles. (including VAT 18%). After you place an order within a few days, you will receive following documents to your specified e-mail: account on payment and receipt to pay in the bank.

After depositing your payment on our bank account we send you file of the article by e-mail.

To order articles please copy the article doi:

10.14489/td.2021.09.pp.004-015

and fill out the form