Izvestia Vysshikh Uchebnykh Zawedeniy. Yadernaya Energetika

The peer-reviewed scientific and technology journal. ISSN: 0204-3327

Automated ultrasonic system residual stresses in the welded joints of the circulation pipe NPP

10/02/2016 2016 - #03 Nuclear power plants

Minin S.I. Trofimov A.I. Trofimov M.A.

UDC: 62-524

Improving the reliability of welded structures is one of the important problems of NPP safety. The performance of welded structures is determined by the performance of the welded connection, the bearing capacity is significantly inferior to the loadbearing capacity of the base metal. This is due to thermal deformation processes, as well as phase and structural transformations in welding, including welds, residual stresses are formed. They are combined with stresses from external loads and are a major cause of destruction of welded constructions.

At the Department «Automation, control and diagnostics» of Obninsk Institute for Nuclear Power Engineering National Research Nuclear University «MEPhI» proposed and developed an ultrasonic method of relieving residual stresses in welded joints of metals and alloys. The prototype automated device for removing residual stresses. Currently a prototype automated system for removing the residual stress is applied in welding of circulation pipes at Kursk NPP. As a result of ultrasonic treatment of welded joints automated system of removing residual stresses are significantly reduced residual welding stresses, increase the mechanical strength properties of welded connections of circulating pipelines of NPP.

To ensure effective removal of residual stresses must be continuous the effect of ultrasound on the sample, so it uses 2 (~ 3kW) of an ultrasound generator with water cooling. The control unit controls the stepper drives moving the transducers along the pipeline. The control unit controls the electric brakes to hold the transducers on the pipe between movements; determines the position of the welding electrode relative to the converters by means of optical sensors and reports this information to the microcontroller of the control unit 1 via the RS485 interface. In addition, there is a system of visual control of the position of the welding device relative to the ultrasonic transducers.


  1. Trofimov A.I. Method of ultrasonic removal of residual stresses during the welding process. Moscow. Energoatomizdat Publ., 2008 (in Russian).
  2. Trofimov A.I., Trofimov M.A., Minin S.I., Kirillov Y.A. Innovative ultrasonic technology to increase the service life of NPP equipment in its manufacture. Izvestiya vuzov. Yadernaya Energetika. 2012, no. 2, pp. 48-54 (in Russian).
  3. Trofimov A.I. Physical principles of ultrasonic methods for relieving residual stresses in welded joints of metals and alloys. Moscow. Energoatomizdat Publ., 2009. 239 p. (in Russian).
  4. Prokopenko, G.I., Lyatun T.A. Study of Surface Hardening Conditions by Means of Ultrasound. Physics and Chemistry of Material Processing. 1977, no. 3, p. 91.
  5. Kudryavtsev Y., Kleiman J., Prokopenko G., Mikheev P. and Knysh V. Optimum Application of Ultrasonic Peening. SEM Annual Conference and Exposition: Experimental Mechanics in Emerging Technologies. Portland. Oregon. USA, June 46, 2001, pp. 179-182.
  6. Pleshanov V.S, Kibitkin V., Panin V.E. Mesomechanics and Fatigue Fracture for polycrystals with macroconcentrators. Theoretical and Applied Fracture Mechanics. 1998, v. 30, no. 1, pp. 13-18.
  7. Nikolaev G.A., Kurkin S.A., Vinokurov V.A. Welded construction. Strength of welded joints and deformation of structures. Moscow. Vysshaya Shkola Publ., 1982. 272 p. (in Russian).
  8. Tyapunina N.A. Annunciation B.V., Zimenkova G.M., Ivashkin Y.A. Features of plastic deformation under the action of ultrasound. Izvestiya vuzov. Fizika. 2003, no. 6, pp. 118-128 (in Russian).
  9. Sagalevich V.M. Methods of eliminating welding strains and stresses. Moscow. Mashinostroenie Publ., 1974. 248 p. (in Russian).
  10. Gushcha O.I. Analysis of inhomogeneous fields of residual stresses in welded joints. Automatic welding. 1994, no. 78, pp. 35, 62 (in Russian).
  11. Tyapunina N.A. Naimi E.K., Zimenkova G.M. Effect of ultrasound on crystals with defects. Moscow. MGU Publ., 1999. 240 p. (in Russian).
  12. Kudryavtsev P.I. Residual welding stresses and strength of connections. Moscow. Mashinostroenie Publ., 1964. 96 p. (in Russian).
  13. Kulemin A.V. Ultrasound and diffusion in metals. Moscow. Mashinostroenie Publ., 1978. 200 p. (in Russian).
  14. Abramov O.V. Crystallization of the metals in ultrasonic field. Moscow. Metallurgiya Publ.,1972. 256 p. (in Russian).
  15. Abramov O.V., Gorbenko I.G., Svehla S.A. Ultrasonic treatment of materials. Moscow. Mashinostroenie Publ., 1984. 280 p. (in Russian).
  16. Trofimov A.I., Minin S.I., Trofimov M.A. Methods of control and relieve stresses in the base metal and welded joints of NPP designs. Moscow. Energoatomizdat Publ., 2005. 272 p. (in Russian).
  17. Fitchard E.E. Randomly simulated borehole tests accuracy of directional survey methods. Oil and Gas Journal. 1981 June, v. 79, no. 26, pp 140-150.
  18. Wolf C.J.M., de Wardt J.P. Borehole Position uncertaintyanalysis of measuring methods and derivation of systematic error model. Journal of Petroleum Technology. 1981, v. 33, no. 12, pp. 339-350.

residual stress welding welded joints the ultrasonic method of stress relief ultrasound automated ultrasound system