Nosov Magnitogorsk State University, Magnitogorsk, Russia

M. V. Chukin, Dr. Eng., Prof., Chief Researcher, Nanosteel Research Institute, e-mail: m.chukin@mail.ru
Yu. Yu. Efimova, Cand. Eng., Associate Prof., Dept. of Casting Processes and Materials Science
N. V. Koptseva, Dr. Eng., Prof., Dept. of Casting Processes and Materials Science

The aim of the study was to confirm (or refute) the hypothesis about the dependence of the thermoelectro-motive force (TEF) on the hardness distribution of along the cold-rolled strip length and width, in order to assess the prospects for using the TEF method in studying the heterogeneity of the mechanical properties of a cold-rolled steel strip. The purpose of this report is to develop a research methodology using the TEF method. The paper presents a description of an original method for determining the TEF of cold-rolled low-carbon steel strip samples using the PocketJaw module of the Gleeble 3500 complex. This method differs from the known methods in that a special heating element was used to prevent the possible influence of electromagnetic fields on the EMF values during heating by direct passing of an electric current. The heating element transfers heat from the heating element to the samples using mechanisms that simulate heating in a furnace. The degree of the sample temperature heterogeneity is proposed to be formalized as ΔT/TC2, where the numerator is the temperature difference between the “hot” (TC2) and “cold” (TC3) ends (ΔT=TC2–TC3), and the denominator is the absolute value of the temperature in the heating zone (TC2). It is proved that this indicator estimates the value of the thermoelectric effect regardless of the experiment thermal conditions. It has been shown that the use of the temperature heterogeneity degree indicator ΔT/TC2 made it possible to identify the patterns of changes in the TEF value during the thermal treatment of a cold-rolled strip. It has been established that the highest TEF values are observed during isothermal exposure, which is characterized by the maximum temperature of TC2, while the absolute values of TEF in different samples are different, which proves the structural dependence of TEF.
This work was supported by the Ministry of Science and Higher Education of the Russian Federation (project FZRU-2025-0003).

1. Polyakova M. A., Telegin V. E., Golubchik E. M. Analysis of standard requirements for steel cold-rolled band. Chernye Metally. 2010. No. 7. pp. 20–26.
2. Grudev A. P., Mashkin L. F., Khanin M. I. Rolling production technology. Moscow : Metallurgiya, 1994. 656 p.
3. Guk S. V. Unevenness of plastic deformation of high-strength cold-rolled steels in sheet metal stamping processes: Dissertation ... of Candidate of Engineering Sciences. Moscow, 2006. 191 p.
4. Kolmogorov G. L., Kuznetsova E. V. Technological residual stresses after metal forming. Vestnik Yuzhno-Uralskogo gosudarstvennogo universiteta. Seriya: Metallurgiya. 2016. Vol. 16. No. 1. pp. 41–45.
5. Weng C. C., Pekoz T. Residual stresses in cold-formed steel members. Journal of Structural Engineering. 1990. Vol. 116, No. 6. pp. 167–189. DOI: 10.1061/(asce)0733-9445(1990)116:6(1611)
6. Fayrushin A. M., Markelov D. A., Marchenko I. A. Study of patterns of occurrence of residual stresses in sheet metal after cold bending operations. Neftegazovoe delo. 2020. No. 4. pp. 74–84.
7. Makeev S. A., Gorkovenko V. A., Seitov E. A. et al. Determination of residual stresses in compressed flanges of arched cold-rolled steel thin-sheet profiled sheets. Vestnik Sibirskogo gosudarstvennogo avtomobilno-dorozhnogo universiteta. 2019. Vol. 16. No. 6 (70). pp. 758–765.
8. Galkin V. I., Golovkin P. A. Causes of auto-deformation of precision parts made of 29NK-VI alloy, manufactured using cold drawn sheet blanks. Tekhnologiya mashinostroeniya. 2024. No. 3. pp. 15–23.
9. Kolikov A. P., Lyutzau A. V., Lisunets N. L. et al. The influence of residual stresses on the quality of products during cold forming of sheet blanks. Izvestiya MGTU MAMI. 2011. No. 2 (12). pp. 139–144.
10. Gribachev Ya. V., Voblikov G. A. On the issue of analysis of stress-strain state and damage during forming. Izvestiya Tulskogo gosudarstvennogo universiteta. Tekhnicheskie nauki. 2024. No. 1. pp. 649–652.
11. Travin V. Yu., Isaeva A. N. Evaluation of heterogeneity of deformation and mechanical properties in the wall of a part during drawing with thinning of thick-walled axisymmetric blanks. Izvestiya Tulskogo gosudarstvennogo universiteta. Tekhnicheskie nauki. 2013. No. 9-2. pp. 393–397.
12. Baryshnikov M. P., Chukin M. V., Boyko A. B. et al. Methods for studying the mechanical characteristics of metals and alloys in forming processes taking into account the heterogeneity of the structure. Vestnik Magnitogorskogo gosudarstvennogo tekhnicheskogo universiteta imeni G. I. Nosova. 2014. No. 4 (48). pp. 26–31.
13. Sarycheva I. A. Method and algorithms for processing information for assessing the mechanical characteristics of cold-rolled carbon steels: Dissertation ... of Candidate of Engineering Sciences. Cherepovets : Cherepovets State University, 2012. 130 p.
14. Osipok T. V., Zaydes S. A. Evaluation of anisotropy of mechanical properties of carbon steel sheet products. Vestnik Irkutskogo gosudarstvennogo tekhnicheskogo universiteta. 2020. Vol. 24. No. 5 (154). pp. 1007–1018.
15. Tibar H. B., Jiang Z. Y. Analysis of strip shape and profile, and mechanical properties during asymmetrical cold rolling. International journal of scientific and technical research in engineering (IJSTRE). 2016. Vol. 1, Iss. 3. pp. 85–105.
16. Oreshko E. I., Utkin D. A., Yerasov V. S. et al. Methods for measuring the hardness of materials: A review. Trudy VIAM. 2020. No. 1 (85). С. 101–117.
17. Udalov A. A., Udalov Al. V., Parshin S. Indentation size effect during measuring the hardness of materials by spherical indenter. Solid State Phenomena. 2020. Vol. 299. pp. 1172–1177.
18. Shatalov R. L., Pham V. H., Tran V. Q. Relationships between the hardness and the main mechanical properties of nonferrous metal alloy strips upon cold rolling. Russ. Metall. 2024. Vol. 7. pp. 1776–1782.
19. Zhang D., Hu L., Liu B. et al. Relationship between hardness and deformation during cold rolling process of complex profiles. Mech. Eng. 2023. Vol. 36. 120
20. Du S., Qiu S. Optimization study on hardness of cold rolled strip steel based on a data-driven approach. Transactions on Computer Science and Intelligent Systems Research. 2024. Vol. 6. pp. 398–404.
21. Kazankin V. A., Kazankina E. N. On the use of indentation methods for constructing a stressstrain diagram. Izvestiya Volgogradskogo gosudarstvennogo tekhnicheskogo universiteta. 2025. No. 3 (298). pp. 10–13.
22. Tomilov G. S. Method of continuous magnetic testing of hardness and tensile strength of extended steel products. USSR copyright certificate, No. 278181. Applied: 03.12.1968. Published: 05.08.1970.
23. Matyuk V. F. State of non-destructive testing of mechanical properties and stampability of sheet steel in the production flow. Nerazrushayushchiy control i diagnostika. 2012. No. 3. pp. 3–24.
24. Ferrajolo A. Method and device for continuous evaluation of mechanical and microstructural properties of metal material, in particular steel, during cold deformation. Patent RF, No. 2765768. Applied: 29.03.2018. Published: 02.02.2022
25. Matyuk V. F., Melguy M. A. New methods and means of magnetic control of mechanical properties of products. Lityo i metallurgiya. 2004. No. 2. pp. 138–143.
26. Kiselhof Z. Sh. Research and development of electromagnetic methods for non-destructive testing of the hardness of rolled strip in the process flow: Dissertation ... of Candidate of Engineering Sciences. Moscow, 1972. 208 p.
27. Lukhvich A. A., Karolik A. S., Sharando V. I. Structural dependence of thermoelectric properties and non-destructive testing. Minsk: Nauka i tekhnika, 1990. 192 p.
28. Belenkiy A. M., Dmitrieva E. E., Khadzaragova E. A. et al. Thermoelectric effect in the sensors of iron and steel industry. Chernye Metally. 2024. No. 5. pp. 63–73.
29. Blatt F. J., P. A, Schroeder, C. L. Foiles et. al. Thermoelectric power of metals. Moscow : Metallurgiya, 1980. 248 p.
30. Livshits B. G., Kraposhin V. S., Linetsky Ya. L. Physical properties of metals and alloys. Moscow : Metallurgiya, 1980. 320 p.
31. Karolik A. S., Kopylov V. I., Sharando V. I. Study of the recovery of microcrystalline copper based on the results of measuring hardness, electrical resistance and thermoelectric power. Deformatsiya i razrushenie materialov. 2008. No. 12. pp. 22–28.
32. Kochkin Yu. P., Chernega A. Kh., Shevchenko S. G. Change in thermoelectromotive force caused by elastic deformation of steel wire under tension. Vestnik MGTU imeni G. I. Nosova. 2006. No. 3. pp. 49–50.
33. Soldatov A. I., Soldatov A. A., Kostina M. A. Modern trends in the application of the thermoelectric method in non-destructive testing: A review. Defektoskopiya. 2024. No. 2. pp. 64–83.
34. GOST 503–81. Cold-rolled low-carbon steel strip. Specifications. Introduced: 01.01.1983.
35. GOST 9045–93. Cold-rolled thin sheets of low-carbon steel for cold stamping. Specifications. Introduced: 01.01.1997.