An Integrated Mathematical Simulation of Temperatures, Rolling Loads and Metallurgical Properties in Hot Strip Mills
6
ISIJ International, Vol. 3 1 (1991), No. 6, pp. 57 1-576 An Integrated Rolling Mills Loads Mathematical Simulation of Temperatures, and Metallurgical Properties in Hot Strip Hiroshi YOSHIDA, Akira YORIFUJl,1) Satoshi KOSEKI and Makoto SAEK12) Technical Research Division, Kawasaki Steel Oorporation, Kawasaki-dori, Mizushima, Kurashiki, Okayama-ken, 712 Japan. I ) Technical Research Division, Kawasaki Steel Corporation, Kawasaki-cho, Handa, Aichi-ken, 475 Japan. 2) Technicai Research Division, Kawasaki Steel Corporation, Kawasaki-cho, Chiba, Chiba-ken, 260 Japan. (Received on 21, 1990, accepted in final form on December 14, 1990) An integrated mathematical simulator for hot st ri p m ill s has been developed. This Hot Integrated Mathematical Simulator (HIMS) can estimate simultaneously temperatures of rolled material and roll, roliing loads such as rolling force and torque, and metallurgical properties of rolled material from the exit of reheating furnace to the coiler. The HIMS consists of three simulators of Temperature, Rolling and Metallurgy, and it takes coupling relations between the above three simulators into consideration to obtain accurate results. (1) The Temperature Simulator is used for calculating the temperature changes of r oll ed material and roll. (2) The Rolling Simulator is used for calculating the force, the torque, the motor power, the deformation resistance, the strain distribution in the thickness direction, etc. during rolling. (3) The Metallurgy Simulator is used for calculating changesof austenite (Y) grain size and phase transformation, and mechanical properties such as yield strength (Y.S.), tensile strength (T.S.), elongation (EI.) and Vickers hardness (Hv) at room temperature. At present, the HIMS s used as an effective tool for solving various problems of hot strip mills, because its application field is very wide. KEY WORDS: omputer simulation; hot rolling; hot strip miil; rolling temperature; rolling load; metallurgical property. 1. Introduction A Temperature Simulator estimates temperatures of.rolled material and roll, a Rolling Simulator which esti- mates rolling loads such as rolling force and torque, and a Metallur gy Simulator which estimates metallurgical proper- ties such as austenite (Y) grain size, phasetransformation and mechanical properties at room temperature are not indepen- dent of one another, but have coupling relations between them. Figure I shows the coupling relations between the three simulators. For example, the. temperature of rolled Temperature Simulator (a) Temperature of rolled material (b) Temperature ofroll (1),(4) (a) Rolling Simulatar (1) Rolling force (2) Rolling torque (8) Motor power (4) Deformation resistance (5) Strain distribution in thickness directien (5) (1),(ID Fig. 1. ,, Metallurgy Simulator (1) T- grain size reerystallization) restoratoin grain growth (II) Phase transformation (III) Mechanical properties (Y.S., T.S., El , Hv) material during rolling is influenced by the rolling force and inversely the rolling force is influenced by the temperature of the rolled material. Therefore these models should be calculated simultaneously to obtain accurate results. In analytical examplespublished previously, however, the temperatures, the rolling loads and the metallurgical proper- ties are calculated without enoughconsideration of the cou- pling relations. I ~3) An integrated mathematical simulator for hot strip mills, which can estimate simultaneously the temperatures, the rolling loads and the metallurgical properties from the exit of the reheating furnace to the coiler, has been developed for the first time. In this report, the outline of the Hot Integrated Mathematical Simulator (HIMS) and the calculated results are described. As the accurate HIMS s used as an effective tool for solving the following problems, the economical merits are substantial. (1) Study on the improvement of existing equipment and new equipment (2) Study on the most suitable manufacturing condition under criteria (3) development of new product (4) Reduction of experimental material in actual process, and (5) Faster trouble shooting in actual process. Coupling relations between three simulators. 571 2. Outline of the HIMS Objects of analysis are the temperatures, the rolling loads and the metallurgical properties in arbitrary (existing and C 1991 ISIJ
