Dynamic simulation of rolling on a six stand hot strip mill

Competition from Far Eastern and other European steel makers along with a shift in demand towards higher quality steel strip demands continual improvement in quality of the finished product of hot strip rolling mills. Until recently, this demand has been met by improving `off-line´ models for calculating control setpoints, replacing outdated computer and control hardware and by optimising adaption algorithms. Relatively less effort has been spent on the dynamic control of these mills, which typically consist of multiple `single loop´ controllers. Due to the complexity of the hot strip rolling process, simulation is indispensable in the understanding of its control systems. The paper describes the development of dynamic simulations of the finishing train of Lackenby Coil Plate Mill (British Steel Ltd now part of the Corus Group) for the purpose of investigating advanced control strategies. Comprehensive dynamic models of the mill mechanical, electrical and control systems combined with models of the hot strip characteristics, allowed the creation of complete simulations of the mill. Results from the simulations are analysed by graphical comparison with actual plant measurements. Real time animations allowed visualisation of complex dynamics such as the behaviour of strip in the interstand region