Abstract: A set of domestic dynamic soft reduction equipment was installed at No5 280 mm x 380 mm bloom concast- ing line at Baotou Steel, bv which the pilot production for heavy steels U71 Mn and U75 V has been carried out for more than one vear. Results showed that with suitable process conditions, the central carbon segregation in heavy rail steels improved obviously by using soft reduction technology: the index of central carbon segregation in cross section of bloom was ≤1.08, the fluctuation of index of carbon segregation along longitudinal central line of bloom appreciably decreased and the chenii- cal composition deviation of steel rail also decreased.

Key words: Bloom Concasting, Dynamic Soft Reduction, Carbon Segregation Index, Carbon Element Deviation Index

摘要： 包钢在5~#280 mm×380 mm方坯连铸机上安装了一套国产动态轻压下设备、对重轨钢U71 Mn和U75V进行了一年多的生产试验。结果表明,在合理工艺条件下,采用轻压下可显著改善重轨钢的中心碳偏析,横断面中心碳偏析指数≤1.08,铸坯纵向中心线碳偏析指数波动明显减小,钢轨成分偏差也随之减小。

关键词: 大方坯连铸, 动态轻压下, 碳偏折指数, 碳元素偏差指数