包钢5~#铸机重轨钢连铸动态轻压下工艺优化研究

Optimization of dynamic soft pressing process for continuous casting heavy rail

本文针对包钢重轨钢连铸大方坯动态轻压下技术进行优化研究.主要开展了900A,U75V,U71Mn,U20Mn等系列重轨钢的高温力学特性实验研究以及采用现场射钉试验验证了凝固末端动态轻压下控制模型的合理性,结果表明:重轨钢连铸矫直时应避开960~800℃脆性区,理论坯壳凝固模型与射钉试验结果基本吻合,铸坯纵剖面上的V型偏析基本消除,铸坯组织均匀性提高;铸坯中心C偏析指数在1.02~1.08,达到了优化的目标.

The optimization of billet continuous casting under dynamic soft reduction was carried out for heavy rail steel. The high temperature elasto-plastic mechanical properties of 900 A,U75 V,U71 Mn,U20 Mn series of heavy rail steel were studied experimentally,and it was verified by using the field nailing test that the pressure control model of dynamic soft reduction is reasonable. The results show that: Straighting of heavy rail steel should avoid the brittle zone of 960 ~ 800 ℃,and the result of the theoretical solidified shell solid model is basically in consistence with that of the nailing test; the V-type segregation on the longitudinal section of the slab is basically eliminated and the uniformity of the billet is improved. The C-segregation index of the slab cross section is between 1. 02 and1. 08,which approached the optimization goals.