1 National Engineering Research Center for Advanced Rolling and Intelligent Manufacturing, University of Science and Technology Beijing, Beijing 100083, China 2 Strip Production Plant, Xichang Steel and Vanadium Corporation of Pangang Group, Xichang 615000, Sichuan, China
Mechanism and control of nonuniform phase transformation of microalloyed dual-phase steel during cooling process after hot rolling
1 National Engineering Research Center for Advanced Rolling and Intelligent Manufacturing, University of Science and Technology Beijing, Beijing 100083, China 2 Strip Production Plant, Xichang Steel and Vanadium Corporation of Pangang Group, Xichang 615000, Sichuan, China
摘要 After cooling in the hot rolling process, the metallographic structure of microalloyed dual-phase steel is nonuniform along the rolling direction, while the thickness fluctuation of microalloyed dual-phase steel with a nonuniform metallographic structure will occur during cold rolling. The mechanism of nonuniform phase transformation of microalloyed dual-phase steels was studied during the cooling process after hot rolling, and the nonuniform phase transformation of microalloyed dual-phase steel was regulated during the cooling process after hot rolling through process optimization. First, the empirical equation of phase transformation temperature was measured by a dilatometer considering thermal expansion. Then, the phase field and temperature field of laminar cooling process were calculated to provide initial boundary conditions for the finite element model. After that, the coupling finite element model of the temperature phase transformation of the strip steel in coiling transportation process was established. The simulation results show that the different thermal contact conditions of the microalloyed dual-phase steel during coil transportation lead to uneven cooling of the coil, which leads to nonuniform transformation of the coil along the rolling direction. In addition, by prolonging the time interval from coiling to unloading, the phenomenon of nonuniform phase transformation of microalloyed dual-phase steel can be effectively controlled. The simulation results are applied to industrial production. The application results show that prolonging the time interval from coiling to unloading can effectively improve the nonuniform phase transformation of microalloyed dual-phase steel in the cooling process after hot rolling.
Abstract：After cooling in the hot rolling process, the metallographic structure of microalloyed dual-phase steel is nonuniform along the rolling direction, while the thickness fluctuation of microalloyed dual-phase steel with a nonuniform metallographic structure will occur during cold rolling. The mechanism of nonuniform phase transformation of microalloyed dual-phase steels was studied during the cooling process after hot rolling, and the nonuniform phase transformation of microalloyed dual-phase steel was regulated during the cooling process after hot rolling through process optimization. First, the empirical equation of phase transformation temperature was measured by a dilatometer considering thermal expansion. Then, the phase field and temperature field of laminar cooling process were calculated to provide initial boundary conditions for the finite element model. After that, the coupling finite element model of the temperature phase transformation of the strip steel in coiling transportation process was established. The simulation results show that the different thermal contact conditions of the microalloyed dual-phase steel during coil transportation lead to uneven cooling of the coil, which leads to nonuniform transformation of the coil along the rolling direction. In addition, by prolonging the time interval from coiling to unloading, the phenomenon of nonuniform phase transformation of microalloyed dual-phase steel can be effectively controlled. The simulation results are applied to industrial production. The application results show that prolonging the time interval from coiling to unloading can effectively improve the nonuniform phase transformation of microalloyed dual-phase steel in the cooling process after hot rolling.
Wen-quan Sun1,Sheng-yi Yong1,Tie-heng Yuan1, et al. Mechanism and control of nonuniform phase transformation of microalloyed dual-phase steel during cooling process after hot rolling[J]. Journal of Iron and Steel Research International, 2024, 31(02): 428-441.
2024, Vol. 31 
