Issue 37

U. Muhin et alii, Frattura ed Integrità Strutturale, 37 (2016) 312-317; DOI: 10.3221/IGF-ESIS.37.41 312 Focused on Fracture Mechanics in Central and East Europe Application of between- stand cooling in the production hot – rolled strips U. Muhin, S. Belskij, E.Makarov Lipetsk State Technical University, Lipetsk, Russia T. Koynov University of Chemical Technology and Metallurgy, Sofia, Bulgaria A BSTRACT . Medium grain size has been uneven over the length of hot-rolled strips of austenite of low-carbon steel during rolling on continuous mill. Assess the possibilities of metal microstructure of hot-rolled strip stabilization system between-stand refrigeration line. Rolling low carbon strips developed modes with increasing temperature end rolling along the length of the strips and rolling modes using between-stand cooling with variable flow cooling water. Using this technology mode allows you to get a uniform cooling microstructure of metal strips and cut to length machine time rolling on 14 – 18%. Treatment with an increased acceleration stabilizes the metal microstructure on rolling strips on top of the thread speed and reduces the machine time rolling on 3-9%. K EYWORDS . Hot rolling mills; Between-stand cooling; Microstructure; Increased cooling acceleration; Mathematical modeling. I NTRODUCTION he most important indicators of the effectiveness of continuous strip hot rolling mills include performance and mechanical properties of the rolled strip. The use of cooling systems rolled strips, which include cooling between stands of finishing group and accelerated cooling in run-out roller table, to control capacity of the mill, and mechanical properties of hot rolled strips. On the process of softening metal affect the extent and rate of deformation, temperature, chemical composition of the steel, grain size, time [1]. To ensure a uniform microstructure of the metal leaving the finishing group, the entire length of the strip should maintained the above parameters constant. When hot strip mill generally accepted strategy for maintaining the temperature of the end of the strip rolling along at a constant level. This consistency provides accelerated finishing train, but there is heterogeneity of the microstructure of the metal from the front to the rear end of the band [2]. One way to stabilize the temperature and the speed limit, and therefore the microstructure and mechanical properties of the metal, is the application of installation Coil box, which requires significant capital investment and reduces the productivity of the mill. T