Naberezhnye Chelny Institute of Kazan Federal University, Naberezhnye Chelny, Russia

V. G. Shibakov, Dr. Eng., Head of the Dept. of Mechanical Engineering, e-mail: vladshib50@gmail.com
D. L. Pankratov, Dr. Eng., Director of the Higher Engineering School, e-mail: pankratovdl@gmail.com
A. M. Valiev, Cand. Eng., Associate Prof., e-mail: cct-ineka@yandex.ru
R. V. Shibakov, Cand. Eng., Associate Prof.

Abstract: An increase in the carrying capacity of transport equipment requires an increase in the strength of loaded structural elements, in particular a car. One of the ways to solve this problem is the use of new economically alloyed grades of steels with increased yield strength. The development of such steels in press shops in the processes of sheet stamping of thick-rolled hot-rolled products requires an assessment of the mechanical properties of the metal supplied by metallurgical enterprises. Basically, the input control of properties is carried out by standard tensile tests of samples. Preparation of standard samples is a rather laborious and lengthy process consisting of: cutting out of rolled "cards"; cutting them with scissors into samples; followed by milling of the side surfaces riveted during cutting. In the future, the samples are transferred to the laboratory for testing. Technological tests (the Erickson method, multiple or single bending of samples at a given angle) are either unsuitable for testing thick-sheet materials, or they provide not a quantitative but a qualitative assessment of the properties of the metal, which is difficult to compare with the standard tensile testing method. The paper substantiates the use of a technological test by punching a hole in a thick-sheet rolling with a diagram (P-h) "Deformation force - displacement of the punch". A correlation has been established between the strength σ_в, σт plastic δ, ψ characteristics of the metal, and the coordinate of the extremum Р_max, hп of the diagram (P-h) during punching. The technological test does not require the manufacture of special samples, it can be implemented at the production site by punching holes directly in the rental, or in the process of stamping parts, which helps to obtain operational information about the compliance of the deformable metal with the terms of delivery.

1. GOST 1497–2023. Metals. Methods of tension test. Introduced: 01.07.2024.
2. Romanovsky V. P. Handbook of cold stamping. 6th edition, revised and enlarged. Leningrad : Mashinostroenie. Leningradskoe otdelenie, 1979. 520 p.
3. Burdukovsky V. G. Sheet metal stamping technology: tutorial. Yekaterinburg : Izdatelstvo Uralskogo universiteta, 2019. 224 p.
4. Banabic D. Formability of metallic materials. Plastic anisotropy, formability testing, forming limits. Berlin: Springer Berlin, Heidelberg, 2000. 334 p.
5. Mrklein M., Grobel D., Loffler M., Schneider T. et al. Sheet-bulk metal forming – forming of functional components from sheet metals. Proceedings of ICNFT 2015, August, 6 – 9, Glasgow, UK / MATEC Web of Conferences. 2015. Vol. 21. 01001.
6. TU 14-101-809-2010. Hot-rolled microalloyed steel with high yield strength for cold stamping of the components for KAMAZ trucks. MMK JSC. Technical specifications. Introduced: 15.09.2010.
7. GOST 18895–97. Steel. method of photoelectric spectral analysis. Introduced: 01.01.1998.
8. Wang N.-M., Budiansky B. Analysis of sheet metal stamping by a finite-element method. J. Appl. Mech. 1978. Vol. 45, Iss. 1. pp. 73–82.
9. Mamutov V. S., Mamutov A. V. Computer modeling of sheet metal stamping processes: tutorial. Saint Petersburg, 2016. 192 p.
10. Patil S. P., Prajapati K.G., Jenkouk V., Olivier H. et al. Experimental and numerical studies of sheet metal forming with damage using gas detonation process. Metals. 2017. Vol. 7. 556.
11. Zienkiewicz O. C. The finite element method in engineering science. Translated from English. Moscow : Mir, 1975. 534 p.
12. Morozov O. I. Modeling and analysis of stress-strain state of separation operations of sheet metal stamping. Vestnik Ulyanovskogo gosudarstvennogo tekhnicheskogo universiteta. 2021. No. 3 (95). pp. 21–26.
13. Vinogradov A. I., Shibakov V. G., Pankratov D. L. Automation of the process of manufacturing long products from thick sheet materials. Fundamentalnye issledovaniya. 2014. Iss. 9. P. 9. pp. 1929–1934.
14. Kokorin V. N., Morozov O. I., Mishov N. V., Schiller N. P. Modeling the stress-strain state of metal in the deformation zone with a change in the inter-tool gap. In the collection: University science in modern conditions. Proceedings of the 55th scientific and technical conference. In 3 parts. Ulyanovsk, 2021. pp. 81–84.
15. Galimov E. R., Shibakov V. G., Vinogradov A. I., Shibakov R. V. et al. Method for assessing the stampability of sheet metal by its resistance to deformation during punching and cutting. Vestnik Kazanskogo tekhnologicheskogo universiteta. 2014. Vol. 17. No. 19. pp. 260–262.
16. Shibakov V. G., Vinogradov A. I. Control of an automated press line based on a system for measuring the parameters of a blank metal. In the collection: Modern instrumental systems, information technologies and innovations. Collection of scientific papers of the XII International scientific and practical conference in 4 volumes. 2015. pp. 283–286.
17. GOST 24812–81. Testing of items from the point of view of influence of mechanical factors. General. Introduced: 01.07.1982.