高拉速薄板坯漏斗型结晶器内坯壳凝固与应力行为的反问题研究

The funnel-shape mould of high speed continuous casting is the core equipment of endless rolling technology. Its complex inner cavity shape leads to the complex heat transfer and deformation behavior of shell, which directly endangers the quality of terminal products and the smooth production. It is the frontier technology and control difficulty of hot strip manufacturing. Based on the relative motion characteristics of the mould-shell and the measured temperature of the copper wall, a three-dimensional inverse heat transfer mathematical model of cooling water-copper wall-slab can be constructed, and the effects of different water supply modes and pouring conditions on temperature field and heat flow distribution in funnel mould will be analyzed accurately. Based on the principle of minimum stress and uniformity of deformation, a three-dimensional inverse problem model of contact between funnel mold and shell will be constructed. The inverse stress problem of shell is solved by mathematical iteration regularization method, and the optimum equation of inner cavity surface of funnel mould with high casting speed is obtained. Then a new design method of funnel mould structure with high efficiency and low strain for high casting speed thin slab production will be established.. This project not only enriches the analysis methods of heat transfer and stress in mold, provides important theoretical support for optimization of high speed continuous casting process but also has important reference value for the design of funnel-shape mold and mold powder.

高拉速连铸漏斗型结晶器是全无头轧制技术的核心装备，其复杂内腔形状导致坯壳传热及变形行为极为复杂，直接危害了终端产品质量和生产顺行，是热轧带钢制造的前沿技术和控制难点。本项目基于结晶器-坯壳相对运动特征及铜壁实测温度，构建冷却水-铜壁-铸坯三维传热反问题数学模型，精确解析不同供水方式与浇注条件对漏斗型结晶器温度场及热流分布的影响。以坯壳应力最小及形变均匀性为原则，构建漏斗型结晶器与坯壳接触的三维反问题模型。采用数学迭代正则法求解坯壳应力反问题，获得高拉速漏斗型结晶器内腔曲面最优方程，创立一套适用于高拉速薄板坯生产的高效低应变漏斗型结晶器结构设计新方法。. 本项目可以丰富结晶器传热与应力的分析手段，为高效连铸工艺优化提供理论支撑，对漏斗型结晶器结构设计与连铸保护渣优化具有重要的参考价值。

高拉速下连铸结晶器铜板烧损、磨损，以及铸坯角部裂纹是是薄板坯连铸连轧产线的行业难题。项目针对超高速连铸条件下结晶器的强热冲击、高磨损等现场应用痛点，深挖高热通量条件下漏斗型结晶器传热与应力应变行为的科学原理，结合数值模拟与反问题算法，开发了新型连铸结晶器传热研究体系，创建了高拉速漏斗型连铸结晶器的传热研究新方法。分析了冷却水对结晶器传热行为的影响，明确了冷却水在结晶器铜壁内的三维流场、温度场分布规律。创立了漏斗型结晶器三维应力应变模型研究技术体系，探究了高拉速薄板坯坯壳在结晶器内的三维应力应变演变过程。研究成果可为实现薄板坯高效率、高质量生产提供借鉴，为高速连铸保护渣、高效冷却结晶器设计提供指导，对现代铸轧工艺低碳减排提供有力支撑。