关键词: 重轨钢铸坯, 数值模拟, 凝固末端, 轻压下, 中心疏松

Abstract: Based on condition for heavy rail steel concasting at Nol Steelmaking Plant, Wuhan Iron and Steel Co, the math model for solidification heat transfer model of 380 mm x 280 mm bloom has been established, and tested and modified by pin-shooting technique. Simulation results show that the distance of end position of solidification of heavy rail steel U71Mn and U75V from meniscus is respectively 16. 96 ~21. 68 m and 16. 50 ~21. 17 m； with decreasing intensity of secondary cooling or increasing casting speed, the end position of solidification of steel U71Mn and U75V is obviously prolonged forward. According calculated results, as secondary cooling schedule changes from weak cooling (0.346 L/kg) to extra-weak cooling (0.218 L/kg) with casting speed 0. 7 m/min, using soft reduction 5 ~7 mm at Nol -4 stand, the end position of solidification of steel U71Mn and U75V is prolonged to more than 21 m. After concasting process optimization, the qualified percentage for center porosity in bloom of heavy rail steel W rating 1 increases from 89.64% to 99.50% .

Key words: Bloom of Heavy Rail Steel, Numerical Simulation, End Position of Solidification, Soft Reduction, Center Porosity