Development of integrated shape control technologies in hot strip mills

In order to improve the shape control performances of hot strip mills and the shape quality of strips and to reduce production consume, special contour technologies of work rolls and backup rolls were developed for this type of hot strip mills whose work rolls can shift axially, on the basis of large amount of finite element simulations. Relevant shape control models were also set up, including the shape setup control model in process control system (LEVEL 2), the bending force feedforward control model, the crown feedback control model and the flatness feedback control model in basic automation system (LEVEL 1). After several complicated processes such as setup of off-line models, on-line programming, and debugging were finished, roll contour technologies and shape control models were stably applied in an industrial wide strip hot rolling mill. The production data showed the control precisions of profile and flatness, with the crown deviation in the range of ±18μm and the flatness deviation less than ±25 IU, were over 93% and 94%, respectively. And at the meantime, schedule free rolling was realized.