极薄规格冷轧带钢板形控制研究

针对厚度0.2 mm以下极薄规格带钢在生产过程中经常出现中浪缺陷的问题,对某UCM轧机极薄规格带钢局部中浪板形缺陷与轧制过程数据进行了分析,通过工作辊温度测量与工作辊热凸度引起平坦度的有限元计算,表明中浪缺陷是由于轧辊热凸度过大而造成的。分析了轧辊热凸度影响因素,以及UCM轧机轧辊辊型,板形目标曲线,中间辊轴向横移,乳化液,中间辊、工作辊弯辊力等参数对极薄规格带钢板形的影响。结果表明:通过板形目标曲线优化设计,合理配置中间辊轴向横移量、工作辊弯辊、中间辊弯辊3种板形调节手段,增加中间辊轴向横移量,增加工作辊弯辊、中间辊弯辊负弯的调节余量,可在消除中浪的同时避免边浪的产生。同时,通过优化工艺润滑制度,降低乳化液温度到合理范围,可有效提高分段冷却的板形控制能力,使带钢平坦度回归到板形目标曲线设计范围,释放弯辊调控量。再有,通过支撑辊边部辊型优化设计,可提高辊型对边浪的抑制能力,在减少中浪的同时不产生边浪。采用上述措施,将中浪缺陷减小到5 IU以内,极薄规格带钢中浪板形缺陷问题得到了有效解决。

Research on flatness control of ultra-thin cold rolled sheet

The problem of poor flatness often occurs in the production process of ultra-thin strip with thickness less than 0.2 mm. The mid-wave defect and rolling process data of a ultra-thin strip of a UCM mill were analyzed.The temperature of the work roll was measured and thethe strip flatness caused by the thermal crown of the work roll was calculated by finite element. The results show that the mid-wave defect is caused by the excessive thermal crown of the work roll. Therefore, the influencing factors of roll thermal crown and the effects of parameters such as roll profile, shape target curve, intermediate roll axial shifting, emulsion, bending force of intermediate roll and work roll on the flatness of ultra-thin gauge strip of UCM mill were analyzed. The results show that by optimizing theflatness target curve, reasonably configuring the three kinds of adjustment means of intermediate roll axial shifting, work roll bending and intermediate roll bending, i.e.increasing the axial shifting of intermediate roll and adjusting allowance of work roll bending and intermediate roll negative bending can eliminate the medium wave and avoid the side wave at the same time. Meanwhile, by optimizing the process lubrication system and reducing the emulsion temperature to a reasonable range, the flatness control ability of segmented cooling can be effectively improved, the flatness can return to the design range of flatness target curve, and the control amount of bending roll can be released. In addition, through the optimization design of the roll profile at the end of the backup roll, the ability of the roll profile to suppress the side wave can be improved, and the side wave will not be generated while reducing the medium wave. By adopting the above measures, the medium wave defect is reduced to less than 5 IU, and the problem of medium wave defect of ultra-thin strip has been effectively solved.