Effect of crown shape of rolls on the distribution of stress and elastic deformation for rolling processes

Abstract

The present work analyzes the influence of crown shape on the distribution of stresses and deformation for rolling processes. This study consists of a Finite Element Analysis considering combinations of crown shape for Back Up Roll and Work Roll, rolling forces, properties of materials and dimensions of rolls and strip. An analysis of the rolls based on a double cantilever model with the fulcrum of the beams in a centerline mill was carried out. The results show that maximum stress concentrations for all combinations of crown shape analyzed appear on both sides 787.4 mm from the mill centerline, exactly on the sides of the strip. In this area, the maximum stress for the best combination of crown shape is larger than in the centerline mill, increasing from 34.2 MPa to 163.0 MPa. This is proportional according to Hooke’s law for which strain of rolls increases from 3.4067 × 10−4 to 4.8368 × 10−4. The worst combinations of crown shapes were obtained when the shapes of the barrel are the same for the BUR and WR; for example: Combination 1 (BUR Positive–WR Positive), Combination 5 (BUR Flat–WR Flat), and Combination 9 (BUR Negative–WR Negative).