Issue 37

U. Muhin et alii, Frattura ed Integrità Strutturale, 37 (2016) 305-311; DOI: 10.3221/IGF-ESIS.37.40 307    3 0.009 14.521 b Ar ,   3 0.018 9.293 n Ar , where: t j - metal temperature at the collecting roller table in the j-th time, °C; Ar 3 and Ar 1 - the critical point, °C. Ar 1 and Ar 3 temperature, depending on the chemical composition of steel and the cooling rate can be described by the equation [8]:    n i i Ar kW mW A ,°С,  1, 3 i ; (3)    кп j масс масс j тр t t W , where: W - the rate of cooling, °C/s; Ai - isothermal value based on the chemical composition; k, m, n - coefficients; t max kp -averaged temperature at the end of rolling, °C; t max j -averaged temperature of the strip in the j-th time; t mp j - transportation time of the calculated cross sections in the j-th moment of time from the end of rolling pyrometer, s. According to estimates in the demo-version of the Thermo-Calc heat when γ → α transformation of pure iron was 136.93 MJ/m3, then the expression for the power density due to heating of the strip of polymorphic transformation can be written as:          1 1 136,93 j j V j j X X q , 3 МВт м , where: τ – time, s. A DAPTATION OF A MATHEMATICAL MODEL he mathematical model of the thermal state of the metal in the collecting roller table adapted to the conditions of continuous wide hot-rolling mill 2000 "NLMK", Russia. The existing mill in the accelerated cooling unit consists of 80 upper and lower sections, equipped with reservoirs of jet cooling. The scheme of collecting roller table with the installation of cooling is shown in Fig. 1. The total length of the outlet roller mill in 2000 is 206.6 m Figure 1: Cooling scheme on outlet roller of mill 2000. T