Width change in roughing train of a hot strip mill is investigated. Formulas by which width spread in vertical and horizontal rolling is predicted are derived according to a regression analysis using measured values on a production mill.
A new mathematical model for edger set-up is developed using above mentioned formulas. A feature of the new model is that it is practicable to adjust the roll opening at each edger depending on a given distribution pattern of width reduction at each stand.
The new set-up model has been applied to Kashima Steel Works, Sumitomo Metal Ind., Ltd. since March 1979. Compared with the accuracy obtained by the conventional set-up method, width accuracy has been much improved by the present new model.