Nosov Magnitogorsk state technical university (Magnitogorsk, Russia):

S. A. Levandovsky, Cand. Eng., Associate Prof., Chair “Materials treatment technologies”, e-mail: levandovskiy@mail.ru
O. N. Tulupov, Dr. Eng., Prof., Chair “Materials treatment technologies”, vice-rector for research and innovations,
A. B. Moller, Dr. Eng., Prof., Head of the chair “Materials treatment technologies”
D. I. Kinzin, Cand. Eng., Associate Prof., Chair “Materials treatment technologies”

The aim is to increase the stability of the MMK’s mill 370 performance, and improve the material yield. We reviewed and analyzed the world experience in the rebar production using the slitting-process. There are two approaches to the slitting: by dividing a thick neck in the grooves of the working stand of the mill; by dividing a thin neck in the exit slitting guide after the stand. The reasons of downtimes of the mill 370 PJSC “MMK” during the production of rebars No. 10–14 by slitting were analyzed. A significant part of cobbles (sticking or choking) occurred at the stand 16. Technical and technological solutions have been developed to ensure stable rolling and an increase of the yield, in particular: an adjusted roll pass design for the stand 14; a proposal to improve the implementation schemes of slitting process using Danieli slitting guides; suggested the use of wear-resistant dividing rollers from TiC or WC; recommended to use higher quality bearings for dividing guide roller with elastic sealing devices capable to operate at elevated temperatures. Trial rolling was carried out using wear-resistant dividing rollers and the correct groove of the stand 14. As a result, the share of cobbles reduced significantly and the material yield improved. The share of the cobbles per ton during the experimental rolling almost halved (0.16%) compared to the average level of 0.34%. The measurements showed that the rolled material obtained after the 15^th stand has the correct dimensions and sufficient symmetry.

1. Nalivaiko A. V., Steblov A. B., Tulupov O. N., Kinzin D. I. Development of complex quality index for rebar and substantiation slitting-process using in frame of domestic mini-mills. Vestnik Magnitogorskogo gosudarstvennogo tehnicheskogo universiteta im. G. I. Nosova. 2011. No. 1 (33). pp. 52–54.
2. Moller A. B., Kinzin D. I., Levandovskiy S. A. Improving the rolling technology at mill 450 OJSC “MMK” to reduce the level of alloying of 09G2S steel designed for strength class up to 440 MPA. Solid State Phenomena. 2017. Vol. 265 SSP. pp. 1123–1129.
3. Tulupov O. N., Moller A. B., Sarancha S. Yu. Increasing of long products rolling efficiency: modernization of stelmor air cooling line to obtain sorbitized wire rod. Solid State Phenomena. 2017. Vol. 265 SSP. pp. 1116–1122.
4. Sarancha S. Yu., Levandovskiy S. A., Statsenko J. S., Moller A. B., Kinzin D. I. Optimization of long products rolling and cuttung technology based on modern IT. CIS Iron and Steel Review. 2014. No. 1. pp. 44–49.
5. Pehterev S. V., Ivin Yu. A., Nikolaev O. A., Kazyatin K. B., Semenov P. S. Production of high-strength reinforced bar steel for Russian Railways. Chernye metally. 2013. No. 6. pp. 27–32.
6. Chabby L. Simulation of microstructure and mechanical properties in section rolling. Chernye metally. 2017. No. 9. pp. 57–62.
7. Kopylov I. V., Volkov K. V., Romadin A. Yu. Features of the ways of longitudinal slitting in rolling of rebars. Kalibrovochnoe byuro. 2013. No. 2. pp. 5-14. (available at: http://www.passdesign.ru).
8. Starkov N. V., Bobarykin Yu. L. Perfomance critetia slitting-process. Lityo i metallurgiya. 2016. No. (1) 82. pp. 61–65.
9. Mroz S., Szota P., Dyja H., Numerical Modeling of Rolling Process Using Longitudinal Slitting Passes. AISTech Proceedings. 2005. pp. 775–783.
10. Stefanik A., Mroz S., Szota P., Dyja H. Determination of slitting criterion parameter during the multi slit rolling process. AIP Conference Proceedings. 2007. pp. 1231–1236.
11. Starkov N. V., Bobarikin Yu. L. Choosing the Slitting Method and the Profile of the Slitting Rolls for Rolling and Slitting. Metallurgist. 2015. Vol. 59. Iss. 5–6. pp. 390–395.
12. Wisselink H. H., Huetink J. 3D FEM simulation of stationary metal forming processes with applications to slitting and rolling. Journal of Materials Processing Technology. 2004. No. 148. pp. 328–341.
13. Zhuchkov S. M., Lokhmatov A. P., Andrianov N. V., Matochkin V. A. Rolling-Slitting with the Use of Undriven Slitting Equipment: Theory and Practice. Pan-Press. Ukraine-Belarus. 2007.
14. Efimov O. Yu., Chinokalov V. Ya., Kopylov I. V., Fastykovskii A. R., Makhrin A. N. Employing rolling and separation technology in the 250-1 mill. Steel in Translation. 2008. Vol. 38. No. 8. pp. 671–673.
15. Efimov O. Yu., Fastykovskii A. R., Chinokalov V. Ya., Kopylov I. V. Introduction of a splitting operation in rolling on a continuous small-bar mill. Steel in Translation. 2008. Vol. 38. No. 4. pp. 327–328.