• Українська
  • English
ISSN 2664-2441 (Online)
ISSN 2073-9583 (Print)

Heat treatment and properties of a cast complex profile blade of a hydroturbine

Metalozn. obrobka met., 2022, vol. 28 (102), 58-63
https://doi.org/10.15407/mom2022.02.058

Artomova S. V., Head of the Central Factory Laboratory, artemova@ukrenergymachines.com
Budarin O. S., Deputy general director,
Bondarenko V. S., Head of the metallurgical department - chief metallurgist
Bezvesilna O. M., Deputy head of the metallurgical department
Ponomarenko O. I.*, Dr. Sci. (Engin.), Professor, e-mail: 21ponomarenko@gmail.com, ORCID: https://orcid.org/0000-0002-3043-4497
Marchenko A. P.*, Dr. Sci. (Engin.), Professor, Vice-rector for Scientific Work,
ORCID: https://orcid.org/0000-0001-9746-4634
Akimov O. V.*, Dr. Sci. (Engin.), Professor, Head of Chair / Sub-Department,
ORCID: https://orcid.org/0000-0001-7583-9976
Mykhailiukov V. P. Сasting and forging shop manager

Ukrenergymachines JSC, Kharkiv, Ukraine
* National technical University «Kharkiv Polytechnic Institute», Ukraine, Kharkov

UDC 621.22:621.791
Download: PDF

Summary

The mode of heat treatment of massive castings of the blades of the impeller of the hydroturbine "Dniester HPSP" from steel of the martensitic class CA-6NM has been worked out. Based on the determination of mechanical properties, measurements of stiffness over the entire surface of the blades and metallographic studies, the expediency of the proposed heat treatment mode using intensive cooling and high tempering after high-temperature austenitizing heating is shown. It is shown that this mode provides the necessary level of mechanical properties of blade castings, eliminates the negative effect of internal stresses arising during crystallization and rapid cooling during subsequent heat treatment. Determination of the chemical composition of castings and its compliance with the requirements of ASTM A743 / A743M-98a ensures that the required level of product properties is obtained. Metallographically established the absence of unwanted segregation and the uniformity of the structure, the uniformity of mechanical properties over the body of the blade, which leads to an increase in resistance to destruction due to cavitation.
As a result of the research, the expediency of using the following heat treatment mode for massive complex-profile castings of blades made of corrosion-resistant steel of martensitic class CA-6NM, consisting of heating to a temperature of 1030-1040°C and tempering at 580-590°C using rapid cooling, was confirmed.
Keywords: hydraulic turbine blades, heat treatment, structure, mechanical properties.

References

  1. Dvoyeglazov G.A. Materialovedeniye (Materials Science), Kyiv, 2015, 448 p. [in Russian].
  2. Kondratyuk S.Ye. Strukturoutvorennya, spadkovist i vlastivosti litoi stali (Structuralization, recession and power of cast steel), Kyiv, Nauk. dumka, 2010, 175 p. [in Ukrainian].
  3. Georgiyevskaya Ye. V., Materialovedeniye. Energetika, 2017, Vol.23, No. 4, pp. 89-97 [in Russian].
  4. Babachenko Yu. V., Avdyushenko A.Yu., Izvestiya Samarskogo nauchnogo tsentra RAN,  2013, No. 4, pp. 547-55 [in Russian].
  5. Lobareva I. F., Chernyy S.G., Chirkov D.V., Skorospelov V.A., Turuk P.A., ZHVT, 2006, Vol.11, No. 5, pp. 63-76 [in Russian].
  6. Kolychev V.A. Vestnik KHGPU, 1998. – Vol. 21. [in Russian].
  7. Bogachev I.N. Kavitatsionnoye razrusheniye zhelezouglerodistykh splavov (Cavitation destruction of iron-carbon alloys), Moscow: Mashgiz, 1959 p. [in Russian].
  8. Bogachev I.N. Kavitatsionnoye razrusheniye i kavitatsionnostoykiye splavy (Cavitation destruction and cavitation-resistant alloys), Moscow: Metallurgizdat, 1964 p. [in Russian].
  9. Tarasov V.N., Tekhnicheskaya akustika, 2015, No. 3, pp. 2-10 [in Russian].
  10. Georgiyevskaya Ye.V. Izvestiya vysshikh uchebnykh zavedeniy. Problemy energetiki, 2018, No. 20 (9-10), pp. 71-78. https://doi.org/10.30724/1998-9903-2018-20-9-10-71-78
  11. Novikov I.I. Teoriya termicheskoy obrabotki metallov (Theory of heat treatment of metals), Moscow: Metallurgiya, 1978, 392 p. [in Russian].