Issue 37

U. Muhin et alii, Frattura ed Integrità Strutturale, 37 (2016) 312-317; DOI: 10.3221/IGF-ESIS.37.41 317 In the rolling low carbon the strips thickness regime using cooling with variable flow water temperature increment of the end for rolling thin strips was 7-8°C and for thick strips thicker than 4.2 mm - 16-18°C. Machine time rolling of strip thickness over 2,7 mm decreased by 14-18 % compared to the rolling on the regime without cooling. In the rolling strips of low carbon steel on the regime with an increased acceleration without screening peal at the intermediate roller table stabilizing metal microstructure at the exit of finishing train can reach the end of rolling temperature increment equal 13-17°C, with rolling of strip thickness less 2,5 mm using a screening of roll increment is 6- 10°C. Rolling schedule with high acceleration can reduce the rolling machine time by 3-9 %, depending on the thickness of the strip. C ONCLUSIONS regime of hot-rolled strips of low-carbon steel with increasing temperature for the conditions of the end of rolling continuous wide 2000 hot rolling mill “NLMK” is developed that improve the performance of the mill and stabilize the microstructure of the metal along the hot-rolled strip, in contrast to the existing regimes. Stabilization of the microstructure is achieved by increasing the temperature tf at 6-10°C when rolling of strip thickness less 2.5 mm, and at 13-18°C wen rolling of strip thickness over 2.5 mm. The rolling of strip using between stands cooling with variable water flow leads to reduction of the rolling machine time by 14-18 %, according to the regime with an increased acceleration - by 3 - 9 %. R EFERENCES [1] Humphreys, F.J., Hatherly, M., Recrystallization and related annealing phenomena, Oxford, Elsevier Ltd, (2004). [2] Kotsar, S.L., Abelyansky, D., Mukhin, U., Plate rolling technology, Moscow, Metallurgy, (1997), (in Russian). [3] Koinov, T., Gurov, A., Shatalov, R., Software tools 50870000614. Economic-mathematical model of continuous hot striprolling, Programs and algorithms, Inf. Bull., 11 (1987), Moscow, (in Russian). [4] Koinow, Т., Yordanova, Р., Mathematical Modelling of Production and Operation Exploit of Steel Products”, 5th Congress of Metallurgists of Makedonia, Ohrid, (2008). [5] Siciliano, F. Jr., Minami, K., Maccagno,T.M., Jonas, J.J., Mathematical modeling of the mean flow stress, fractional softening and grain size during the hot strip rolling of C-Mn steels, ISIJ International, 36(12) (1996) 1500-1506. [6] Beynon, J.H.,. Sellars, C.M., Modelling microstructure and its effects during multipass hot rolling, ISIJ International, 32(3) (1992) 359-367. [7] Senuma, T., Yada, H., Matsumura, Y., Futamura, T., Structure of austenite of carbon steels in high speed hot working processes, Tetsu-to-Hagané, 70(15) (1984) 2112-2119. [8] Maccagno, T.M., Jonas, J.J., Hodgson, P.D., Spreadsheet modelling of grain size evolution during rod rolling, ISIJ International, 36(6) (1996) 720-728. [9] Koinov, T., Angelova, D., Shatalov, R., Theoretical and experimental studies of the formation of metal structure in continuous finishing train, Collection of proceedings of the international conference “Theory and practice of producing sheet metal”, Lipetsk, Part I (2005) 195 - 200. (Russian Federation), (in Russian). A

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