Azerbaijan Technical University, Baku, Azerbaijan

A. T. Mammadov, Dr. Eng., Prof., e-mail: ariff-1947@mail.ru
A. I. Babayev, Cand. Eng., Associate Prof., e-mail: aqil.babayev@aztu.edu.az
M. Ch. Huseynov, Cand. Eng., Associate Prof., e-mail: muxtar.53@mail.ru
B. B. Musurzayeva, Senior Lecturer, e-mail: musurzayeva71@mail.ru

The types of defects, their nature and distribution in the coupling body are given. Using a fractogram of the fracture of the samples, it was established that the crack on the coupling is longitudinal, has a brittle nature, of a metallurgical nature, that is, a slope with a depth of ~3 mm. From the edge of the longitudinal crack, several sunsets were discovered, located at an acute angle to the outer surface of the coupling. It was determined that the microstructure of the coupling has a coarse-grained pearlite structure with a continuous mesh along the grain boundaries. Consequently, a material with such a structure is prone to brittle fracture under the influence of dynamic loads. Inside the metallurgical defectsunset, extending from a longitudinal crack in the area of the fracture site, layers of hightemperature oxides are visible, and along them a decarbonized section of metal. It was established that the development of a longitudinal crack in the coupling tie occurred according to a transgranular mechanism and in this case chip facets up to 300 μm in size were formed. It has been established that the formation of high-quality steel largely depends on the process of continuous casting of billets. In this case, it is impossible to allow the thin crust to stick to the walls of the crystallizer, which leads to its rupture in places where it leaves the walls. The correct choice of secondary cooling modes plays an important role in the quality of the workpiece. If it is violated, internal cracks form in the cross-section of the workpiece. To eliminate the “sunset” on the casing coupling, it is recommended to select high-quality selective selection of the initial charge, the correct choice of metallurgical processing modes, including in an electric arc furnace, out-of-furnace processing and during continuous casting of billets.

This work was sopported by the Azerbaijan Science Foundation — Grant № AEF-MCG-2023-1(43)-13/01/1-M-01.

1. Mamedov A. T., Babaev A. I., Ismailov N. Sh., Guseinov M. Ch. et al. Mastering of production of hot-deformed casing pipes made of 32G2 steel grade in the conditions of Baku Steel Company. Vestnik Azerbaydzhanskoy Inzhenernoy Akademii. 2022. Vol. 14. No. 4. pp. 48–55.
2. Langbauer K., Nunner G., Zmek T. et al. Investigation of temperature distribution in seamless low-alloy steel pipes during the hot rolling process. Advances in Industrial and Manufacturing Engineering. 2021. Vol. 2. 100038.
3. Alam S., Hassan S. F. Heat-input factor effect on the quality of high-frequency induction welded pipe of for oil. Society of Manufacturing Engineers. 2023. pp. 76–79.
4. Mamedov A. T., Ismailov N. Sh., Guseynov M. Ch., Guliev F. T. Features of obtaining pipes with specified properties for the oil and gas industry. Chernaya metallurgiya. Byulleten nauchnotekhnicheskoy i ekonomicheskoy informatsii. 2022. Vol. 78. No. 3. pp. 257–263.
5. Velichko A. G., Rakhmanov S. R., Babanly M. B., Mamedov A. T., et al. Out-of-furnace treatment in the production of high-quality steels. Monograph. Baku : NMetAU i AGUNP, 2021. 467 p.
6. Velichko A. G. Out-of-furnace steel treatment. Dnepropetrovsk : Sistemnye tekhnologii, 2005. 199 p.
7. Kerimov R. I. Vibration treatment of electric steel in a mold. Mashinovedenie. 2018. No. 1. pp. 53–56.
8. Kerimov R. I., Dzhafarova A.A. Study of the quality of a destroyed casing pipe coupling manufactured at Baku Steel Company. Uchenye zapiski AzTU. 2017. No. 4. pp. 191–198.
9. Shakhov S. I., Vdovin K. N., Rogachikov Yu. M., Shakhov D. S. et al. Improvement of built-in electromagnetic mixing in billet continuous casting machine molds. Metallurg. 2020. No. 5. pp. 33–37.
10. Sivak B. A., Shakhov S. I., Vdovin K. N., Rogachikov Yu. M. et al. Development of a syistem for electromaqnetic stirring of liquid steel on molds of billet CCMs. Metallurgist. 2020. Vol. 63, Iss. 9-10. pp. 910–914.
11. GOST 18895–97. Steel. Method of photoelectric spectral analysis. Introduced: 01.01.1998.
12. GOST 1050–2013. Metal products from nonalloyed structural quality and special steels. General specification. Introduced: 01.01.2015.
13. GOST 632–80. Casing pipes and couplings for them. Specifications. Introduced: 01.01.1983.
14. GOST 1050–2013. Metal products from nonalloyed structural quality and special steels. General specification. Introduced: 01.01.2015.
15. GOST 9013–59. Metals. Method of measuring Rockwell hardness. Introduced: 01.01.1969.
16. GOST R EN 13018–2014. Visual testing. General principles. Introduced: 01.07.2015.
17. Karimov R. I. Features of removal of phosphorus and sulfur from remelting stock during electric arc melting of steel. International Journal of Control and Automation. 2020. Vol. 13. No. 1. pp. 137–159.
18. Mammadov A., Babaev A., Ismailov N., Huseynov M. et al. Identification of the nature of defects arising in the production of continuously cast pipe billets for the oil and gas industry. Eastern-European Journal of Enterprise Technologies. 2023. Vol. 4, Iss. 1(124). pp. 125-133. DOI: 10.15587/1729-4061.2023.284357
19. Kerimov R. I., Shakhov S. I. Use of metallized raw materials in electric steelmaking. Metallurg. 2020. No. 2. pp. 42–48.
20. Ding Y., Zhu Q. et al. Analysis of temperature distribution in the hot plate rolling of Mg alloy by experiment and finite element method. Journal of Materials Processing Technology. 2015. Vol. 225. pp. 286–294.
21. Rozhkova O. V. Investigation of the nature of defects on the outer surface of heat – treated seamless pipes. Foundry Production and Metallurgy. 2020. Vol. 4. pp. 90–93.
22. Pyshmintsev I. Yu., Uskov D. P., Maltseva A. N. et al. Microstructure and properties of oil and gas range pipe steel subjected to improvement. Metallurgist. 2019. Vol. 63 (1-2). pp. 41–50.
23. GOST 5639–82. Steels and alloys. Methods for detection and determination of grain size. Introduced: 01.01.1983.
24. Goune M., Danoix D., Agren J. et al. Overview of the current issues in austenite to ferrite transformation and the role of migrating interfaces therein for low alloyed steel. Materials Science and Engineering: R: Reports. 2015. Vol. 92. pp. 1–38.
25. Li P., Li G., Wei L., Yi Z. Study on dynamic thermal behavior of the steel pipes in walking beam quenching furnace. Case Studies in Thermal Engineering. 2022. Vol. 33. 101997.
26. Yu S., Du L. X., Hu J., Misra R. D. K. Effect of hot rolling temperature on the microstructure and mechanical properties of ultra – low carbon medium manganese steel. Materials Science and Engineering: A. 2018. Vol. 731. pp. 149–155.
27. Soares R. B., lins V. F. C. Corrosion resistance of rolled and re-rolled super martensitic steel in media containing chlorides and hydrogen sulphides. Materials. 2017. Vol. 22, Iss. 4. DOI: 10.1590/s1517-707620170004.0232
28. Landfahrer M., Schluckner C., Prieler R. et al. Numerical and experimental investigation of scale formation on steel tubes in a real – size reheating furnace. International Journal of Heat and Mass Transfer. 2019. Vol. 129. pp. 460–467.
29. Cardoso R. A., De Farida G. L. Characterization of austenite decomposition in steels with different chemical concepts and high potential to manufacture seamed pipes for oil and gas industry. Material Research. 2019. Vol. 22, Iss. 5. DOI: 10.1590/1980-5373-MR-2019-0378
30. Chabicovsky M. et al. Effects of oxide layer on Leiden frost temperature during spray cooling of steel at high temperatures. International Journal of Heat and Mass Transfer. 2015. Vol. 88. pp. 236–246.
31. Gong P., Palmiere E., Rainforth W. Thermomechanical processing route to achieve ultrafine grains in low carbon micro alloyed steels. Acta Materialia. 2016. Vol. 119. pp. 43–54.
32. Rakhmanov S. R., Topolov V. L., Gasik M. I., et al. Processes and machines of electrometallurgical production: monograph. Baku-Dnepr : Sistemnye tekhnologii, Sabakh, 2017. 568 p.