冷轧带钢板形目标曲线设定模型研究与应用

Research and application of flatness target curve setting model for cold-rolled steel strip

板形目标曲线设定模型属于冷轧板形控制中的基础工艺设定模型,直接决定带钢的实际控制效果。由于当前的板形目标曲线设定模型难以适应规格及工艺参数的变化,无法满足多品种多规格频繁切换的板形控制要求,导致产品合格率降低。为提高板形目标曲线与实际板形的适配度,以基本板形目标曲线和各补偿曲线为基础,利用函数建模方法建立8次多项式形式的板形目标曲线广义方程。为降低各系数的设置难度且满足全种类带钢的生产要求,利用线性函数归一化算法对板形目标曲线广义方程进行归一化处理并乘以增益系数,得到归一式的8次板形目标曲线最终模型。以国内某厂1450 mm五机架六辊冷连轧机为应用实例,实践表明,归一式板形目标曲线使稳态轧制、加减速轧制阶段的板形标准差分别降低50%和30%且均满足工艺标准,并可保证良好的指标稳定性,为获得高质量冷轧带钢产品提供了解决方案。

The flatness target curve setting model refers to the basic process setting model in cold rolling flatness control,which directly determines the actual control effect of strip steel.Since the current flatness target curve setting model is hardly adapted to the changes of specifications and process parameters,it fails to accommodate the requirements of flatness control with frequency switching of multiple varieties and specifications,which results in the decrease of product qualification rate.In purpose of improving the fitness of flatness target curve to the actual flatness,the generalized equation of flatness target curve in the form of 8 order polynomial was established based on the basic flatness target curve and the compensation curve using the functional modeling method.To decrease the difficulty of setting coefficients and to accommodate the production requirements of the full range strip steel,the linear function normalization algorithm was used to normalize flatness target curve and multiply the corresponding gain coefficients to obtain the final model of 8 order flatness target curve in normalized form.The domestic 1450 mm five-stand,six-roller cold rolling mill as an application example shows that the normalized form of flatness target curve reduces the standard deviation of plate shape by 50%and 30%in stable rolling process and rolling process of acceleration stage and deceleration stage,and ensures stable indexes,providing a solution for obtaining high-quality cold-rolled strip products.