National University of Science and Technology MISIS, Moscow, Russia

N. M. Vavilkin, Dr. Eng., Prof., Dept. of Metal Forming
A. S. Budnikov, Cand. Eng., Associate Prof., Dept. of Metal Forming, e-mail: budnikov.as@misis.ru
Mahmoud Alhaj Ali A., Postgraduate Student, Dept. of Metal Forming, e-mail: makhmud.a@misis.ru

FIT Ltd., Moscow, Russia

D. V. Bodrov, Cand. Eng., Head of Logistics and Customer Service, e-mail: dbodrov@fesco.com

To increase the wear resistance of piercing and rolling mandrels, internal cooling is used when piercing and rolling hollow workpieces made of alloy steels and alloys. The piercing of extrathick-walled long hollow workpieces with Lt/Dt more than 9 is accompanied by severe thermal and power operating conditions of the mandrels. When piercing alloy steel grades, wear of the mandrel toe is often observed due to its plastic deformation in combination with high temperature, specific force on the contact surface, which exceeds the resistance to deformation of the mandrel material. The paper presents the results of a study of the quasi-stationary thermal state of water-cooled piercing and rolling mandrels under conditions of bubble and film boiling modes, obtained using computer modeling. Analysis of the thermal field of the piercing and rolling mandrel indicates the presence of three characteristic zones. For stitching mandrels, the heated part is the toe. When flashing, its surface heats up to 830 ºС. This low cooling efficiency is associated with heat exchange conditions that occur under film boiling conditions. The internal cavity close to the toe of the mandrel has a small cross-sectional diameter of the channel (8-10 mm), which leads to the formation of a vapor blanket. The thermal field of a rolled mandrel differs significantly from that of a pierced mandrel. Due to less severe operating conditions and the relatively small total area of the contact surface with the heated workpiece, the maximum temperature of the mandrel is significantly lower. The most heated is the outer surface of the conical part of the mandrel, the temperature of which is 580 ºС.

1. Vavilkin N. M., Goncharov V. S., Bodrov D. V. et al. Peculiarities of wear of water-cooled plugs during piercing of alloy steels. Izvestiya vuzov. Chernaya metallurgiya. 2009. No. 7. pp. 37–40.
2. Gao J. F., Li Q., Zhao W. Thermal stress analysis for local heating variable cross section roll forming. Advanced Materials Research. 2013. Vol. 683. pp. 599–603. DOI: 10.4028/www.scientific.net/AMR.683.599
3. Domazet Ž., Lukša F. Influence of rolling temperature on fatigue life of calibrated rolls. Advanced Materials Research. 2013. Vol. 742. pp. 482–487. DOI: 10.4028/www.scientific.net/AMR.742.482
4. Aleshchenko A. S., Nguyen K. Study of wear resistance of plugs of two-roll screw rolling mill. Metallurg. 2022. No. 6. pp. 38–42.
5. Korol A. V., Aleshchenko A. S., Shamilov A. R., Goncharuk A. V. Simulation of the operation of two-roll screw piercing of steels of the 13Cr type. Chernye Metally. 2022. No. 7. pp. 47–52.
6. Wang F. X., Du F. S., Yu H. The thermal-mechanical coupled fem analysis on 3-roll continual tube rolling PQF deformation process. Advanced Materials Research. 2011. Vol. 193. pp. 1670–1674. DOI: 10.4028/www.scientific.net/AMR.189-193.1670
7. Vavilkin N. M., Budnikov A. S., Kholodova N. V. Features of computer simulation of the joint thermal field of the plug and shell during piercing of extra-thick-walled hollow billets. Chernye Metally. 2023. No. 5. pp. 48–52.
8. Vydrin A. V., Kuryatnikov A. V., Zvonarev D. Yu. et al. Analysis of technical solutions to improve the durability of piercing mill plugs. Proizvodstvo prokata. 2012. No. 5. pp. 27–30.
9. Toporov V. A., Pyankov B. G., Panasenko O. A. et. al. Water-cooled mandrel of the piercing mill. Patent RF, No. 2649598. Applied: 26.01.2017. Published: 04.04.2018. Bulletin No. 10.
10. Vavilkin N. M., Bukhmirov V. V. Piercing mandrel. Moscow : MISIS, 2000. 128 p.
11. Vavilkin N. M., Bodrov D. V. Water-cooled mandrel and piercing mill stand rod. Patent RF, No. 2423194. Applied: 22.09.2009. Published : 10.07.2011.
12. Vlasov A. V. et al. Finite element modeling of technological processes of forging and stamping: tutorial. Moscow : Izdatelstvo MGTU imeni N. E. Baumana, 2019. 383 p.
13. Skripalenko M. M., Romantsev B. A., Galkin S. P. et al. Creation of 3D model of stainless-steel billet’s grain after three-high screw rolling. Materials. 2022. Vol. 15. No. 3. pp. 79–80.
14. Yusupov V. S., Romantsev B. A., Skripalenko M. M., Andreev V. A. et al. Modeling of the features of the stress-strain state of billets in screw rolling processes. Stal. 2021. No. 6. pp. 17–19.
15. Deng G. Y., Zhu H. T., Tieu A. K., Zhu Q. et al. Numerical evaluation of a high speed steel work roll during hot strip rolling process. Material Science Forum. 2017. Vol. 904. pp. 55–60. DOI: 10.4028/www.scientific.net/MSF.904.55
16. Nattarawee Siripath, Surasak Suranuntchai, Sedthawatt Sucharitpwatskul. Finite element modeling of upper ball joint in a two-step hot forging process. Advances in Materials and Technologies. 2022. Vol. 934. pp. 95–102. DOI: 10.4028/p-iziu0l
17. Cao Q., Hua L., Qian D. Finite element analysis of deformation characteristics in cold helical rolling of bearing steel-balls. Journal of Central South University. 2015. Vol. 22. No. 4. pp. 1175–1183. DOI: 10.1007/s11771-015-2631-6
18. Rout M., Pal S. K., Singh S. B. Finite element simulation of a cross rolling process. Journal of Manufacturing Processes. 2016. Vol. 24. P. 1. pp. 283–292.
19. Aleshchenko A. S., Quang N. Studying the wear resistance of the mandrels of a two-high screw rolling mill. Metallurgist. 2022. Vol. 66, Iss. 5-6. pp. 650–656.
20. Bilan I. T., Romantsev B. A., Belonozhko S. S., Meshcheryachenko A. A. et al. Modernization of the plug cooling system of the continuous PQF mill under conditions of TAGMET. Metallurg. 2022. No. 7. pp. 97–100.
21. Mikheev M. A., Mikheeva I. M. Fundamentals of heat transfer. 2^nd stereotype edition. Moscow : Energiya, 1977. 344 p.
22. Tataru A. S., Potemkin V. K., Cavalla R., Lukin A. S., et al. Study of the possibility of obtaining two-phase automotive sheet steel with single-stage cooling on the discharge roller table of the NLMK`s continuous wide-strip mill 2000. Izvestiya vuzov. Chernaya metallurgiya. 2014. Vol. 57. No. 7. pp. 26–33.