特殊钢大方坯连铸中间包各流冶金效果一致性研究

摘要：多流中间包各流钢水流动与温度状态差异是造成高端特殊钢连铸坯质量一致性差的重要原因之一。针对国内某钢厂特殊钢大方坯连铸用4流T型中间包边部流和中部流实测温差较大问题（4~7℃），基于实际工况特点，进行了中间包冶金行为的热流体动力学数值模拟研究，揭示了原型中间包边流水口响应慢及各流一致性差的原因；提出一种控制钢水流动和流间温差的内腔结构改进措施，可使包内钢液温度均匀性得到明显改善。其中，理论最小流间温差可降低到1℃以内，实测流间温差在0~3℃之间，较原型大大减小。同时指出，基于热流体动力学数值模拟优化中间包结构、提升多流中间包全铸流冶金效果一致性在特殊钢长材生产中具有重要意义。

Study on an identical metallurgical effect for multi strand tundish during special steel bloom casting

The divergence of the molten steel flow and temperature state in a multi strand tundish is a frequent reason leading to a poor continuous casting quality consistence and their final steel products. For a practical special steel bloom casting process, the measured temperature difference between the edge strand and the middle strand in its original 4 strand T shaped symmetrical tundish is as large as 4-7℃. To improve the quality of special steel long products from its casting period, the thermal fluid dynamics simulation on the overall metallurgical behavior of the tundish was carried out based on the actual casting conditions. The reasons for the obviously slow flow response of the edge strand nozzle in the prototype tundish and the poor consistency among strands were revealed. An effective countermeasure to control the molten steel flow and temperature difference in the multi strand tundish is proposed, which can improve the temperature distribution uniformity of molten steel in the tundish obviously, and the temperature difference between the edge strand and the middle strand can be reduced to less than 1℃ by the numerical analysis. With one of improved flow control designs for the tundish adopted in production, the measured temperature difference between nozzles is dropped to 0-3℃ which is remarkable as compared to the original one. It is pointed out that to optimize the multi strand tundish for an improved overall metallurgical effect is an important issue especially for long products production, which can be achieved by numerical simulation through a reasonable thermal fluid dynamics analysis.