45钢连铸矩形坯动态二冷配水系统的研究和应用

Study and Application of Dynamic Secondary Cooling on 240 mm×280 mm Rectangular Bloom

针对某厂240 mm×280 mm 45钢连铸矩形坯的内部质量缺陷,建立了基于射钉和测温验证的铸坯温度场实时跟踪计算模型,同时,根据目标表面温度对二冷水量进行优化,并应用了动态二冷配水系统。结果表明,动态配水考虑了传热过程的滞后性,在拉速波动时能更好地控制铸坯表面温度;铸坯质量得到明显改善,中心疏松、缩孔、中间裂纹和中心裂纹等缺陷都有不同程度的减轻,且基本消除1级以上的缺陷。

For understanding the internal defects of 0.45C steel of 240 mm×280 mm rectangular bloom,a real-time heat transfer and solidification mold of bloom based on pin-shooting and temperature measuring was established.Meanwhile,the amount of secondary cooling water was optimized according to the objective surface temperature and dynamic secondary cooling system was applied.The results showed that：（1）When casting speed fluctuated,dynamic secondary cooling could better control the surface temperature with considering the lag of heat transfer.（2）The quality of bloom improved obviously.The defects such as center porosity,shrinkage cavity,intermedium cracks and center cracks were reduced respectively;defects above grade 1 were basically eliminated.