1 School of Materials and Metallurgy, University of Science and Technology Liaoning, Anshan 114051, Liaoning, China; 2 Iron and Steel Research Institutes of Ansteel Group Corporation, Anshan 114001, Liaoning, China
An innovative process of clad teeming for preparing slab ingot
1 School of Materials and Metallurgy, University of Science and Technology Liaoning, Anshan 114051, Liaoning, China; 2 Iron and Steel Research Institutes of Ansteel Group Corporation, Anshan 114001, Liaoning, China
摘要 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.
Abstract：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.
Wen-bin Ma,Yao-hui Jin,Yu-an Jing, et al. An innovative process of clad teeming for preparing slab ingot[J]. Journal of Iron and Steel Research International, 2022, 29(12): 2006-2015.
2022, Vol. 29 
