In this work, a curved surface convex roll (CSC-Roll) suitable for wide-thick slabs was designed. According to the field conditions and casting parameters, a 3D thermal-mechanical coupling model of CSC-Roll reduction was established, and the uneven solidification morphology of the slab was obtained. By analyzing the liquid core deformation rate, surface maximum stress and reduction force of the CSC-Roll with different shape parameters, the optimal shape parameters of the CSC-Roll were designed. By coupling the shrinkage void in the 3D thermal-mechanical coupling model, the coalescence degree of shrinkage voids under the flat reduction is calculated to be 8.78 pct, and that under CSC-Roll reduction is 9.68 pct, and the deformation degrees of the shrinkage voids in different directions were compared. The critical strain of slab surface crack propagation measured by high-temperature tensile test is 0.181. Based on the relationship between crack tip strain and initial crack length during reduction, the critical initial lengths of longitudinal and transverse crack propagation on slab surface were obtained to be 15.7 mm and 28.0 mm.

在这项工作中，设计了一种适用于宽厚板坯的曲面凸辊（CSC-Roll）。根据现场条件和铸造参数，建立了CSC-Roll压下的3D热力耦合模型，得到了铸坯不均匀凝固形貌。通过分析不同形状参数的CSC-Roll的液芯变形率、表面最大应力和压下力，设计了CSC-Roll的最佳形状参数。通过3D热力-机械耦合模型中的缩孔耦合，计算得到平板缩径下缩孔的聚结度为8.78%，CSC-Roll缩孔下缩孔的聚结度为9.68%，缩孔的变形程度比较了不同的方向。高温拉伸试验测得的板坯表面裂纹扩展临界应变为0.181。根据压下裂纹尖端应变与初始裂纹长度的关系，得到板坯表面纵向和横向裂纹扩展的临界初始长度分别为15.7 mm和28.0 mm。