Abstract:In order to resolve the flatness problems of extreme size strip in MeiSteel 1422 tandem hot mill after the enlargement of sizes and steel grades, the initial profile of hot mill backup roll were researched, and the functional design principles of new backup roll profile optimization were proposed; on the basis of these design principles, the genetic algorithm backup roll profile design platform was established which used two-dimension FEM with variable thickness to calculate roll system deformation, the automatic optimization of roll profile curve was realized, and the design method of hot mill backup roll initial profile was perfected; according to simulation verified the improvement effect of new profile on aspect of flatness control efficiency, and applied to the production, practice results shows that the new backup roll profile has obviously improved the flatness of extreme size strip at the unit exit, at the same time the wearing of backup and work roll has large improvement.