Design of a Kind of Backup Roll Contour Used in Four-High CVC Hot Strip Mill

Abstract

The phenomenon of uneven contact pressures between cylindrical backup roll and CVC (Continuously Variable Crown) work roll in four-high hot strip mill has always existed, which can lead to seriously uneven wear of cylindrical backup roll and even spalling defect. In order to obtain an available solution plan for above mentioned problem, a new kind of backup roll contour called reverse CVC backup roll contour is proposed in this paper. Reverse CVC backup roll contour is generated by fitting four cubic chamfer contours and one backup roll surface contour designed by CVC work roll contour. And one roll elastic deformation simulating software coded based on Influence Function Method has been used to calculate and study the contact pressure distributions between CVC work roll and reverse CVC contour backup roll or cylindrical contour backup roll. Compared with cylindrical contour backup roll, contact pressures between CVC work roll and reverse CVC contour backup roll are much smoother without steep peak. Simulating results meet well with data collected from the application field, wear of new reverse CVC contour backup roll is more well-distributed than cylindrical contour backup roll.