邯钢中碳微合金钢板坯轻压下位置优化

板坯连铸轻压下实施过程中，合理的压下参数是影响铸坯内部质量的决定性因素。根据邯钢中碳微合金钢板坯连铸生产条件，建立凝固传热模型，结合板坯射钉试验研究，预测其凝固进程和压下位置。在此基础上，开展轻压下工业试验，分析了压下位置对铸坯中心偏析的影响。结果表明，在拉速为0.85 m/min、过热度为20～30 ℃、二冷比水量为0.59 L/kg的条件下，邯钢中碳微合金钢板坯连铸压下区间中心固相率为0.2～0.7，对应位置为16.42～21.62 m，位于7～9号扇形段内。与采用6～8号扇形段压下相比，优化方案明显改善了板坯中心偏析和疏松，东西两侧不均匀偏析和横截面V型偏析显著减弱。

Optimization of soft reduction location of medium carbon microalloyed continuously cast steel slab in Hansteel

In the soft reduction process, the inner quality of slab is strongly affected by the reduction parameters. Based on continuous casting conditions of medium carbon microalloyed steel slab, a solidification heat transfer model was built to predict the solidification process and reduction location, which was validated by the nail shooting test. Then, the soft reduction plant trails were carried out and the effect of reduction location on the center segregation was investigated. The results showed that the center solid fraction of the reduction range was 0.2 0.7 for medium carbon microalloyed steel slab, corresponding to 16.42 21.62 m from the meniscus and within No.7 9 segements. Compared with the original reduction location（No.6 8 segements）, the center segregation and porosity were improved significantly, especially the nonuniform segragtion at slab east and west sides and the V segregation in the cross section.