关键词: 连铸, 大方钢坯, 传热, 凝固, 改进的波动冷却法

Abstract: The heat transfer and solidification of secondary cooling zone in bloom continuous casting were simulated based on a fluctuated cooling approach-improved (FCA-I), and the three simulation methods, monotonic cooling approach (MCA), fluctuated cooling approach (FCA) and FCA-I, were compared. The results show that the bloom surface temperature before straightening and liquid core length calculated by the three methods have not much difference with the measurements, but FCA-I is more accurate, which can real-time predict the distribution of bloom surface temperature and the liquid core length change with casting speed. FCA-I not only retains the advantages of FCA which can accurately reflect the actual temperature change of foot-roller, but also overcome the shortcomings of FCA which is difficult to adapt to the changing of casting speed. The relationship between the solidification time (t) and shell thickness (dshell) in mold and secondary cooling zone calculated by FCA-I are regressed as dshell=19.62t1/2-2.52 and dshell=29t1/2, respectively, the simulation results basically agree with literatures.

Key words: continuous casting, bloom, heat transfer, solidification, fluctuated cooling approach-improved