Abstract: According to the research prototype of a 35 t tundish for casting three-strand unsymmetrical 320 mm x 480 mm bloom of GCrl5 bearing steel, with using geometric similarity ratio 1：3 water model combined with mathematical simulation ,the effect of different baffle device on liquid flow field in tundish is studied to optimize the tundish flow field and get optimum baffle device. Results show that of original prototype tundish the residence time is smaller and the dead area volume fraction is up to 39. 68% ; adding optimized Y-type baffle the average residence time of three nozzle increases by 29. 51 s, the dead area ratio decreases by 15. 54% and each nozzle is more identical. The pilot production of GCrl5 bearing steel in situ show that after tundish optimization the T [O] in tundish liquid decreases from original 19. 3 x 10^-6 ~26. 3 x 10^-6 , average value 22. 7 x 10^-6  to 9. 5 x 10^-6 ~ 17. 2 ×10^-6, average 12. 3 x 10^-6；number of inclusions in casting bloom decreases from 12. 0 ~15.3/mm²  to 6. 8 ~8. 4/mm² and the number of > 1. 25 μm inclusions decreases obviously.

摘要： 以钢厂三流不对称GCr15钢320 mm×480 mm方坯连铸35 t中间包为研究原型,采用1:3水模型试验和数值模拟相结合的方法研究不同控流装置对中间包内流场的影响,优化中间包内流场,并得到最优的导流墙结构。结果表明,原型中间包各水口滞止时间很小,死区比例达到39.68%;增加优化后的Y型导流墙后,滞止时间增大了29.51 s,死区比例减小了15.54%,且各水口一致性较好。通过GCr15轴承钢现场试验发现,中间包优化后钢水T[O]由优化前的19.3×10^-6~26.3×10^-6平均值22.7×10^-6降低至9.5×10^-6~17.2×10^-6,平均12.3×10^-6;铸坯中夹杂物由12.0~15.3个/mm²降低到6.8~8.4个/mm²,>1.25μm夹杂物明显降低。

关键词: 35 t, 三流中间包, 数值模拟, 物理模拟, 流场