Set-up optimization for tandem cold mills: A case study

This paper presents a set-up optimization system developed to calculate reduction for each stand of a four stand tandem cold mill installed at Cosipa plant, Brazil. This optimization system is composed of an initialization phase and an optimization phase. The initialization phase consists of a non-iterative calculation procedure, proposed as an alternative for the iterative algorithm presented by Guo [R.-M. Guo, Application of PC and LAN for a level 2 setup model of a single-stand reversing mill, Iron Steel Eng. (8) (1997) 41–46]. The optimization phase is based on Nelder and Mead simplex method and presents as the main contribution the definition of the objective function adopted, which takes into consideration quality and productivity aspects of the rolling mill. From the point of view of quality, the results after the implementation of this system are illustrated through characteristics of individual coils and of a set of produced coils; productivity aspects are illustrated through the comparison of rolling power and speed to nominal values.