连铸异型坯结晶器铜板冷却水缝优化设计

Optimization and practical application of measurement method for dendrite arm spacing of continuous casting slab

建立了异型坯结晶器铜板二维传热模型,应用有限元软件进行求解,分析了不同水缝设计方式下铜板热行为,重点考察了结晶器铜板热面温度峰值和温度均匀性。结果表明:原异型坯结晶器铜板温度峰值为339.6℃,位于R角处,结晶器铜板翼稍两侧均出现温度低谷。增加R角水孔内限流杆直径或将R角限流杆由光滑杆改成螺旋杆均可明显降低铜板温度峰值和温度梯度。此外,在R角增加小孔或将R角小孔改成大孔也可强化R处传热,提高铜板温度均匀性。然而,改善铜板传热效果的最佳办法是重新设计水缝,非均匀分布的等径小孔和非均匀分布的环形水缝加小孔两种水缝设计可有效提高铜板使用寿命、改善铸坯质量,在现场试验效果良好。

Two-dimensional heat conduction models of beam blank molds were developed by using finite element software. Thermal behavior of mold copper plate was evaluated in detail with different cooling channels. Attention was focus on the peak temperature and temperature uniformity along hot face. The results show that the peak temperature of existing mold, about 339. 6 ~C, is located in the fillet, and two valleys of hot face temperature are found in flange corner and junction of wide face and narrow face, re- spectively. Increasing diameter of restrictor rods and changing the surface shape of re- strictor rods can all reduce peak temperature and improve temperature uniformity along the hot face. Also, the effect of conventional water channels design can be improved by adding a small hole in fillet and changing the small holes in fillet into large hole. How- ever, the best way to deerease peak temperature and improve temperature uniformity a- long hot face is to redesign the water channels. The water channels design of unevenly distributed equal diameter small holes and unevenly distributed annular channels plus small holes can greatly decrease peak temperature and thermal gradient of mold, which have good application effect in plant test.