80号钢连铸坯末端电磁搅拌优化与实践

Optimization and practice of final electromagnetic stirring of No.80 steel continuous casting billet

对80号钢小方坯内部质量差的问题进行分析,发现末端电磁搅拌(FEMS)磁感应强度低,难以满足末搅冶金的效果。为弥补FEMS强度的不足,拉速由2.6提高到2.7 m/min,二冷比水量降为原工艺的90%。凝固传热模型计算表明,FEMS位置的液芯厚度由原工艺的47.6提高到52.8 mm。试验结果表明,铸坯酸洗表面未出现缺陷,低倍质量明显改善,碳偏析指数范围由原工艺的0.96~1.09优化至0.97~1.02,达到改善铸坯内部质量的目的。

The poor internal quality of No.80 steel billet was analyzed, it was found that the magnetic induction strength of the final electromagnetic stirring(FEMS) was weak itself, which was difficult to meet the needs of the final stirring metallurgy. In order to make up for the lack of FEMS strength, the pulling speed was increased from 2.6 to 2.7 m/min, and the specific cooling water volume was reduced to 90% of the original process. The solidification heat transfer model showed that the liquid core thickness at the FEMS position was increased from the original 47.6 to 52.8 mm. The test result showed that no obvious defects were found on the pickled surface of billet, and the macroscopic structure quality was greatly improved, and the carbon segregation index range was reduced from the original 0.96-1.09 to 0.97-1.02. The internal quality of billet was significantly improved.