The thermal insulation performance of riser is very important to the shrinkage porosity and solidification structure of ingot, but it is difficult to significantly improve due to the limit of thermal conductivity of riser material. A new type of hollow insulation riser was proposed based on the low thermal conductivity of air, which aims to improve the thermal insulation performance of riser. A 14.5-t steel ingot was prepared using the hollow insulation riser, and the casting temperature was 1500 °C. The temperature evolution of the external surface of mold during solidification was measured using an infrared temperature instrument. A numerical model was established to simulate the porosity and solidification structure of ingot. The reliability of numerical simulation was verified by comparing simulation and experimental results. Results show that the insulation performance of the riser can be significantly improved through application of the hollow insulation sleeve. Compared with solid insulation sleeve, the shrinkage cavity depth was decreased and the position of porosity was raised when hollow insulation riser was applied.

冒口的绝热性能对铸锭的缩孔率和凝固组织非常重要，但由于冒口材料的热导率限制，很难显着提高。基于空气的低导热性，提出了一种新型中空保温立管，旨在提高立管的保温性能。采用中空保温冒口制备14.5吨钢锭，浇注温度为1500℃。使用红外测温仪测量凝固过程中模具外表面的温度变化。建立了数值模型来模拟铸锭的孔隙率和凝固组织。通过仿真与实验结果的对比，验证了数值模拟的可靠性。结果表明，中空绝缘套管的应用可显着提高立管的绝缘性能。与实心绝缘套管相比，采用空心绝缘冒口时缩孔深度减小，气孔位置提高。