Numerical simulation on the solidification structure of Ø600mm continuous casting round bloom

Abstract

A FE (Finite Element)—CA (Cellular Automation) coupling model was developed for the simulation of solidification structure formation during the Ø600mm round bloom continuous casting process of Q345E steel. The simulation result of the temperature field was consistent with the nail-shooting experimental result, and the simulated solidification structure of the bloom was in great agreement with corrosion testing under the same casting condition. The simulation results showed that the centre equiaxed crystal ratio increased slightly with the increase of secondary cooling water rate and decreased with the increase of casting temperature and casting speed. When the secondary cooling water rate was over 0.08L/kg, it had less effect on the solidification structure. As the casting temperature increased by 1°C or the casting speed increased by 0.01m/min, the centre equiaxed crystal ratio would decrease by 0.4%∼1.2% and 3%∼0.8% respectively. According to the simulation results, the optimized continuous casting process of Ø600mm round bloom should be the secondary cooling water rate of 0.08L/kg, the casting temperature of 1532°C∼1539°C and the casting speed of 0.20m/min∼0.22m/min. It was found that the solidification structure of Ø600mm Q345E steel round bloom was much improved after the optimized continuous casting process was adopted in practical production.