异型坯结晶器单锥度优化

Single Taper Optimization of Beam Blank Mold

针对异型坯连铸过程中出现较多表面裂纹的问题,使用多载荷步法建立了铸坯在结晶器内传热、凝固及收缩的热力耦合分析模型。根据气隙的计算结果,基于气隙最小化原则,对异型坯各面进行单锥度优化,确定单锥度优化的最佳方案。结果表明:对翼缘端面、窄面均进行两次锥度优化计算,锥度分别为0.81%/m、0.38%/m;翼缘斜面与R角部分采用-1.44%/m的正锥度相对合适。经过计算,现场使用的结晶器锥度过大是异型坯容易产生表面裂纹的主要原因,建议减小锥度。

In order to control surface cracks in blank beam during continuous casting process,the thermomechanical coupling model of heat transfer,solidification and shrinkage of slab in mold was established by using multi-load step method.According to the calculation results about air gap,based on the principle of air gap minimization,the single taper is optimized for each surface of the beam blank and the best scheme of single taper optimization is determined. After twice optimization on taper,ie,the taper of flange tip is0.81%/m,the taper of narrow face is 0.38%/m; the taper of-1.44%/m is relatively appropriate for the fillet and flange.The calculation result indicates that the large taper of the mold is the main cause for generating the surface crack,and then it is recommended to reduce the taper.