矩形坯连铸机提高拉速研究与生产实践

Research and production practice of increasing drawing speed of rectangular billet continuous caster

天津市新天钢联合特钢有限公司炼钢厂5号连铸机在提高连铸机拉速生产实践中,因钢水凝固时间较短,铸坯出现了脱方、角部裂纹、鼓肚、凹陷等缺陷,直接影响铸坯质量合格率。本文针对联合特钢5号连铸机提速后,铸坯出现的一系列质量问题进行了分析,对铸坯缺陷产生的机理进行了研究,并提出了改进建议。通过结晶器铜管结构及足辊的优化改造、二冷系统的优化改造、保护渣性能优化以及浇铸工艺的优化等一系列措施的实施,5号连铸机拉速由1.45m/min提高到2.0m/min,满足了炼钢工序的生产。

During the production practice of increasing the casting speed of the No.5 continuous caster in the steelmaking plant of Tianjin New Tiangang United Special Steel Co.,Ltd.,due to the short solidification time of molten steel,the cast billet has defects such as off-square,corner crack,bulge and depression,which directly affect qualified rate of the cast billet quality. This paper analyzes appearing a series of quality problems of the cast billet after the speed increase of No.5 continuous caster of United Special Steel studies the mechanism of the cast billet defects,and puts forward some suggestions for improvement. Through the implementation of a series of measures such as the optimization and transformation of mold copper pipe structure and foot roll,the optimization and transformation of secondary cooling system,the optimization of protective slag performance and the optimization of casting process,the drawing speed of No.5 continuous caster is increased from 1.45m/min to 2.0m/min,which meets the production requirements of steelmaking process.