An innovative process of clad teeming was proposed to prepare slab ingot, which featured a built-in cold core to inhibit solidification defects. A 20-kg clad ingot was prepared in the experiment, using a volume ratio of solid core to molten steel of 1:13 and a preheating temperature of cold core of 573 K. Solidification microstructures of the clad ingot were analyzed by comparing with a reference ingot without cold core. Interfacial morphologies and mechanical properties of the clad ingot were studied before and after hot rolling. The effect of cold core on heat transfer and nucleation during the solidification in clad ingot was analyzed. Results show that the solidification microstructures in the clad ingot are refined and homogenized obviously. The grain size in the center of the reference ingot is 2–3 times greater than that of clad ingot, and there is almost no columnar grain in the clad ingot. The interfacial shear strength reaches 318 MPa, which shows excellent metallurgical bonding at the interface of cold core and molten steel. Tiny defects at the interface are eliminated, and interfacial shear strength reaches 426 MPa after hot rolling with a 68.4% total reduction ratio. The experiment and analysis of this process are expected to provide a new idea to prepare large ingots with refinement and homogeneity at a low cost.

提出了一种创新的复合浇注工艺来制备板坯，其特点是内置冷芯以抑制凝固缺陷。实验制备了20kg的复合钢锭，实芯与钢水的体积比为1:13，冷芯预热温度为573K。通过与参考对比分析了复合钢锭的凝固组织。没有冷芯的锭。研究了热轧前后复合钢锭的界面形貌和力学性能。分析了冷芯对复合钢锭凝固过程中传热和形核的影响。结果表明，铸锭中的凝固组织明显细化和均匀化。参考铸锭中心的晶粒尺寸是复合铸锭的 2-3 倍，且复合锭中几乎没有柱状晶粒。界面剪切强度达到318 MPa，在冷芯与钢水界面表现出良好的冶金结合。消除了界面微小缺陷，热轧后界面剪切强度达到426 MPa，总压下率为68.4%。该工艺的实验和分析有望为低成本制备细化、均质的大铸锭提供新思路。