首钢京唐板坯高拉速生产的控制技术

High speed casting of 2.5 m/min on SGJT No.3 slab caster

以首钢京唐钢铁联合有限公司3号连铸机2.5m/min高拉速浇铸常规板坯试验为背景,建立流动、传热及摩擦力数值计算模型,并结合实际生产的监测数据,分析和讨论高拉速生产过程中相关工艺控制技术。结果表明,FC结晶器以及下倾角20°水口的使用有利于高拉速过程中的液面控制;通过改善二冷水量,并结合射钉试验,验证得出2.5m/min时的凝固终点仍位于铸机长度以内,而宽面铜板热面最高温度超过350℃;采用一种黏度较低、润滑性能较好的保护渣,并且拉速在2.0m/min以上时保护渣耗量均小于0.3kg/m2,但没有漏钢事故发生,建议开发非正弦振动模式。此外,高拉速条件下,铸坯表层夹杂物减少,冷轧板卷表面质量明显改善。

Based on the application of 2. 5 m/min high speed continuous casting on low carbon conventional slab in SGJT No. 3 caster, the mathematical model of fluid, heat transfer and fric- tion force validated by actual data was established to analyze the related technology. The re- sults show that the mold level could be well controlled by the use of FC mold and SEN with the angle of - 20°. The crater end point validated by pin shooting method even at 2. 5 m/min was in the range of caster length by improving the secondary cooling water flow rate while the highest temperature in the hot side of mold copper plate was beyond 350 ℃. Furthermore, a kind of mold powder with lower viscosity and better lubrication was employed, and the con- sumption rate was less that 0. 3 kg/m2 at 2. 0 m/min or over while there was no breakout oc- curring. In the near future, development of non-sinusoidal oscillation curve may be a feasible choice. Finally, subsurface inclusions of slab decreased and surface quality of cold coils was im-proved with casting speed increase.