| 2026 №03 (06) |
DOI of Article 10.37434/as2026.03.07 |
2026 №03 (01) |
"Avtomatychne Zvaryuvannya" (Automatic Welding), #3, 2026, pp. 51-59
The influence of thermal welding cycles on the structure and mechanical properties of high-hardness armour steels
V.D. Poznyakov
, O.V. Korieniev
E.O. Paton Electric Welding Institute of the NAS of Ukraine
11 Kazymyr Malevych Str., 03150, Kyiv, Ukraine.
Е-mail: korenew@ukr.net
The influence of thermal cycles of welding on phase-structural transformations of the metal of the heat-affected zone of some medium-carbon alloyed armor steels of high hardness with different chemical composition has been investigated. The total mass fraction of silicon, manganese, chromium, nickel and molybdenum in steels of the brand 71, ARMSTAL 500 and Ramor 500 is 6.56, 2.76 and 2.53 %, respectively. It has been established that in the area of overheating of the metal of the heat-affected zone of steels with the total mass fraction of alloying elements is 2.53….2.76 %, at cooling rates W6/5 ≤ 5.0 °C/s a mixed bainite-martensitic structure is formed, and in steel 71, regardless of the cooling rate, and at W6/5 > 5.0 °C/s for other steels – a martensitic structure. It was found that depending on the change in the structure of the metal in the area of verheating of the heat-affected zone, its mechanical properties also change. With increasing cooling rate, the hardness and strength of the metal increase, and the plastic properties decrease.It was established that high resistance of welded joints of the studied steels to the formation of cold cracks can be ensured if materials are used for their welding that ensure the formation of an austenitic structure in the deposited metal. 19 Ref., 7 Tabl., 4 Fig.
Keywords: armor steels, welding thermal cycle, metal structure, mechanical properties of the metal of welded joints, cold cracks
Received: 23.03.2026
Received in revised form: 05.05.2026
Accepted: 14.05.2026
Posted online 20.05.2026
References
1. Tekin Özdemir (2020) Mechanical & microstructural analysis of armor steel welded joints. Intern. J. of Engineering Research and Development UMAGD, 12(1), 166–175. DOI: https://doi.org/10.29137/umagd.4881042. Konat, Ł., Białobrzeska, B., Białek, P. (2017) Effect of welding process on microstructural and mechanical characteristics of Hardox 600 steel. Metals, 7(9), 349. DOI: https://doi.org/10.3390/met7090349
3. Gaivoronskyi, O.A., Poznyakov, V.D., Zavdoveyev, A.V., Klapatyuk, A.V., Denisenko, A.M. (2023) Prevention of cold cracking in armour steel welding. The Paton Welding J., 5, 3–10. DOI: https://doi.org/10.37434/tpwj2023.05.01
4. Oskwarek, M. (2006) Structural features and susceptibility to cracking of welded joints of Hardox 400 and Hardox 500 steels. In: Proceedings of the IV Students’ Science Conference: Human-Civilisation-Future, Wroclaw, Poland, 22–24 May 2006, Vol. 2, pp. 115–120.
5. Cabrilo, A., Geric, K. (2016) Weldability of high hardness armor steel. Advanced Materials Research, 1138, 79–84. DOI: https://doi.org/10.4028/www.scientific.net/AMR.1138.79
6. Kuzmikova, L. (2013) An investigation of the weldability of high hardness armor steel. Faculty of Engineering, University of Wollongong. http://ro.uow.edu.au/theses/3853
7. Shchudro, A., Laukhin, D., Pozniakov, V. (2020) Analysis of the effects of welding conditions on the formation of the structure of welded joints of low-carbon low-alloy steels. Key Engineering Materials, 844, 146–154. DOI: https://doi.org/10.4028/www.scientific.net/KEM.844.146
8. Białobrzeska, B., Jasiński, R., Konat, Ł., Szczepański, Ł. (2021) Analysis of the properties of hardox extreme steel and possibilities of its applications in machinery. Metals, 11(1), 162. DOI: https://doi.org/10.3390/met11010162
9. Güler Özgül, H., Ertan, R., Ozcan, R. (2012) Influence of heat treatment parameters on the microstructure and mechanical properties of boron-alloyed steels. Mater. Test., 54, 1–6. DOI: https://doi.org/10.3139/120.110373
10. Bin Khiyon, M.R., Salleh, S.M. (2017) Effect of heattreatment on the hardness and mechanical properties of boron alloyed steel. MATEC Web Conf., 90, 01014 DOI: https://doi.org/10.1051/matecconf/20179001014
11. Maksimov, S.Yu., Prilipko, O.O., Berdnikova, O.M., Alekseienko, T.O., Polovetskiy, Ye.V., Shepelyuk, Yu.A. (2021) Controlling the parameters of the metal crystal lattice of the welded joints made underwater. Metallophysics And Advanced Technologies, 43(5), 713–723 [in Ukrainian]. DOI: https://doi.org/10.15407/mfint.43.05.0713
12. Poznyakov, V.D., Gayvoronskyi, A.A., Kostin, V.A. (2017) Features of austenite transformation and mechanical properties of metal in the heat-affected zone of 71 grade steel joints during arc welding. Mekhanika ta Mashynobuduvannia, 1, 254–260 [in Russian].
13. Zavdoveev, A., Poznyakov, V., Baudin, T., Rogante, M., Kim, H.S., Heaton, M., Demchenko, Y., Zhukov, V., Skoryk, M. (2021) Effect of nutritional values on the processing properties and microstructure of HSLA rod processed by different technologies. Materials Today Communications, 28, 102598. DOI: https://doi.org/10.1016/j.mtcomm.2021.102598
14. Poznyakov, V.D., Korieniev, O.V. (2025) Mechanical properties of metal in areas of welded joints of medium carbon alloy steels heated to temperatures from 350 to 800 °C. Automatic Welding, 5, 56–59 [in Ukrainian]. DOI: https://doi.org/10.37434/as2025.05.06
15. Zugang Mao, Farkoosh, A.R., Seidman, D.N. (2026) Effects of alloying elements on carbon diffusion in the austenite (f.c.c.)- and ferrite (b.c.c.)-phases. Computational Mater. Sci., 265, 114543. DOI: https://doi.org/10.1016/j.commatsci.2026.114543
16. Akhonin, S.V., Belous, V.Y., Selin, R.V., Kostin, V.A. (2021) Influence of TIG welding thermal cycle on temperature distribution and phase transformation in low-cost titanium alloy. IOP Conf. Ser.: Earth Environ. Sci., 688, 012012. DOI: https://doi.org/10.1088/1755-1315/688/1/012012
17. Grygorenko, H.M., Kostin, V.A., Orlovsky, V.Yu. (2008) Modern possibilities of modeling austenite transformation in welds of low-alloy steels. Automatic Welding, 3, 31–34 [in Russian].
18. Sarzhevsky, V.A., Sazonov, V.Ya (1981) Installation for simulating thermal welding cycles based on the MSR-75 machine. Automatic Welding, 5, 69–70 [in Russian].
19. Musiyachenko, V.F., Kasatkin, B.S., Zhdanov, S.L., Gavrilov, B.K. (1981) Study of the conditions for the formation and development of cold cracks in a welded joint of high-strength steel by the acoustic emission method. Automatic Welding, 7, 5–7 [in Russian].
This article is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.