Abstract: Taking 14 t flat ingot as the research object， a new method of mold removal controlled cooling was adopted. This method completely eliminates the effect of the air gap in the solidification process of the ingot， and applies cooling to the lower part of the ingot to promote the sequence solidification of ingot from bottom to top， thus improving the solidification quality of the ingot. The heat transfer solidification process of the cooling steel ingot controlled by mold removal was simulated through the simulation software combined with the industrial test of solidification process of 14 t H13 on site， and the influence of different cooling intensities on heat transfer solidification， Niyama distribution and thermal stress of steel ingot was analyzed. The results show that the temperature gradient of the lower part of the ingot is increased by mold removal and controlled cooling， the solidification front changes from U-shape to V-shape， the angle of solidification front is increased， the feeding channel between the riser and the solidification front is widened， and the feeding of the riser to the lower part is promoted. With the increase of cooling intensity， the central loose area decreased by 2.03%， the central loose length decreased by 68.53%， and concentrated in the riser area. At the same time， the thermal stress inside the ingot also increases， and the proposed cracking coefficient is used to predict the risk of cracking when the controlled cooling intensity reaches 1 200（W·m^-2·K^-1）.

Key words: Steel Ingot, Stripping Cooling, Center Porosity, Hot Crack

摘要： 以14 t扁锭为研究对象，采用一种拆模控制冷却新方法。该方法完全消除了钢锭凝固过程中气隙带来的影响，并对钢锭下部施加冷却，促进钢锭自下而上的顺序凝固，从而改善钢锭凝固质量。通过仿真模拟软件并结合现场14 t H13的凝固过程工业试验，模拟拆模控制冷却钢锭传热凝固过程，分析不同冷却强度对钢锭传热凝固、Niyama分布以及热应力的影响。结果表明，拆模控制冷却会增大钢锭下部的温度梯度，使凝固前沿由U型向V型转变，增大凝固前沿夹角，使冒口与凝固前沿的补缩通道变宽，促进冒口对下部补缩。随着冷却强度的增加，中心疏松面积减小2.03%，中心疏松长度减小68.53%，并向冒口区域集中。同时，钢锭内部的热应力也增加，利用提出的开裂系数预测拆模控制冷却强度达到1 200（W·m^-2·K^-1）时会有开裂的风险。

关键词: 钢锭, 拆模冷却, 中心疏松, 热裂纹