Research And A Pplication Of Flatness Control Technology Improvement For Tandem Cold Mill

As the width increase gradually and thickness decrease gradually of strip rolling products,the requirement of shape quality control becomes higher and higher.The thickness deviation along the width direction,i.e.the transverse thickness difference,is the main factor affecting the shape of strip,and the transverse thickness difference is caused by the shape of roll surface contour,i.e.the shape of roll gap.CVC rolling mill is a new type of mill with continuous roll crown and good shape control capability.The 6-high CVC mill is adopted in the Jingtang 2230 acid mill of Shougang.The best roll gap shape can be obtained by the axial transverse movement of the intermediate roll Since it was put into operation in December 2010,a set of shape control technology suitable for Jingtang cold rolling has been gradually summarized by summing up the laws from production practice and optimizing production process control technology,and the ability of cold rolling products with relatively stable,large quantities of automobile plates and high strength steel has been formed.In this paper,the research on flatness control in tandem cold rolling process has been made as follows(1)The shape control characteristics of CVC tandem cold rolling mill and the factors affecting the shape control of tandem cold rolling mill are described,such as the shape of high strength steel plate.the shape of wide plate and the shape preset,as well as the current situation and existing problems of shape control in China.(2)Aiming at the flatness problem in actual production and the flatness requirement of post-processing line,the development of secondary compensation model and the development of new technology for flatness meter of CVC tandem cold rolling mill were carried out.The flatness meter strip edge identification function was adjusted to solve the overall flatness identification and adjustment control means.(3)The simulation model and roll shape configuration of 2230 mm CVC mill in Jingtang cold rolling mill were studied.The analytical study of CVC shape control model was carried out.and the shape adjustment region under different conditions was given.The setting parameters of rolling force,rolling rate and rolling force were optimized.The feedforward and feedback function optimization of bending roll force,the bending roll and tilt control of strip head and tail,and the control measures optimization of rotary tilt input of 2230 acid rolling plate were realized(4)Research on Shape Model Self-Learning system,hierarchical management and research of target shape curve,formulate different target curve for different products,re-subdivide and adjust shape setting model,online automatic evaluation of shape and development of closed systemBy readjusting and optimizing the logical structure of the control function,the problems of strip rolling leakage or medium wave caused by excessive bending force compensation in the original design are solved.By adjusting the bending roll force control function of the same specification and different specifications,the hit rate of the strip shape of the lead is solved,and the undesirable part of the strip shape is reduced from 50 meters to 10 meters.