粗轧过程中轧制力和宽展的预测与分析

 板带轧制数学模型是实现自动控制的基础,高精度的数学模型是提升产品质量和市场竞争力的重要保障。在热连轧粗轧过程控制中,轧制力和宽展是关键参数,其模型精度不仅会影响粗轧轧制规程的设定,而且会影响最终热连轧带钢产品凸度。以矩形板坯热连轧粗轧过程为研究对象,针对轧制变形区建立了三维运动许可加权速度场,在此基础上充分考虑自然宽展效应,基于刚塑性材料的第一变分原理,采用可变上限积分法对塑性变形、剪切功率和摩擦功率进行积分获得变形区总功率泛函。利用Matlab优化工具箱对总功率泛函进行最小化,得到了轧制力、宽度分布的理论解。最后利用理论模型计算数据回归得到了板坯宽展及速度场中的加权系数模型。将基于所提出模型的轧制力和宽展预测值与现场实测值及部分有关学者所建立模型的预测值进行了对比,结果验证了所建立模型的准确性。研究得到的宽展模型和速度场加权系数表达式可以方便、灵活、快速地应用到粗轧现场中,为更高质量热连轧带钢产品的生产奠定了坚实基础。

Prediction and analysis of rolling force and width spread in rough rolling

The mathematical model of plate-strip rolling is the basis of automatic control,and the high-precision mathematical model is an important guarantee to improve product quality and market competitiveness. Rolling force and width spread are the key parameters in the hot continuous rolling process control. Their model accuracy not only affects the setting of rough rolling procedures,but also affects the profile of the final strip product. The rectangular slab rolling process of hot continuous rolling was taken as the research object and the three dimensional kinematically admissible weighted velocity field of rough rolling was established for the rolling deformation zone. Considering the width spread effect,based on the first variation principle of rigid-plastic material,the variable upper limit integration method was used to integrate plastic deformation,shear and friction power to get the total power functional of the deformation zone. The theoretical analytical solutions of the rolling force and width distribution were obtained by minimizing the total power functional using the Matlab optimization toolbox. Finally,the slab width spread model and weighted coefficient model of velocity field were obtained by using the data regression of the calculation results of the theoretical analytical model. The rolling force and spread predicted by the model proposed were compared with the on-line measured data and the predicted values of the model established by some relevant scholars. The results verified the accuracy of the model established. The spread model and the expression of velocity field weight coefficient are obtained from the research can be conveniently,flexibly and quickly applied to the rough rolling site,which lays a solid foundation for the production of higher quality hot strip products.