Research in Engineering and Aviation

Roll Profile Optimization Using the Linear Programming Method


Author(s): Guo, R.M., Malik, A.S.

Journal: AISE Steel Technology, 80 (4), 46-52


The linear programming method of optimizing roll profiles provides a relatively simple approach, with widespread application and tangible benefits for single-stand rolling mills. Optimizing the ground profiles of work rolls and backup rolls is critical to the productivity of mills and the quality of rolled strip. Without suitable roll profiles, desired strip crown (or thickness profile) and its more crucial derivative, strip flatness, may be difficult or impossible to obtain. This is particularly true for rolling mills that lack adequate computer setup models and for those with limited crown and shape control devices, such as roll bending and/or shifting mechanisms. However, even with such mill hardware and computer models, many rolling mills still cannot achieve desired strip flatness due to large diversities in product mix and, perhaps, inappropriate roll profiles. If the product mix envelope is vast (due to the necessity of rolling materials with large ranges in yield strength, width, gauge and reductions), it may be difficult or impossible to meet customer specifications. Furthermore, in order to meet specifications, frequent roll changes to modify roll crowns may be necessary, thereby draining rolling efficiency and operating profits. The optimization of roll profiles, however, goes beyond solutions to such obvious issues. In fact, it often happens that improved strip shape leads to better overall mill performance, including higher rolling speeds, reduced strip breakage and the ability to optimize reduction or elongation targets for better yields.