Influence of crossed roller on generating camber in hot rough rolling

Abstract

The shape of a hot rolled strip is a main indicator of its quality, and camber is a significant defect arising from problems in shape quality. Differences in the bearing clearance of the two sides of a rough mill can cause a crossed roller, which leads an imbalance in the rolling force and, thereby, camber. A camber defect adversely affects product quality and the stability of the subsequent finish-rolling production process. The simulation and control of asymmetric shapes is one of the hottest topics in the field of modern strip rolling. To solve this problem and enhance the quality and precision of the strips produced, exploring and analyzing the problem of camber in hot rough rolling is necessary. This study investigated the generation of camber in the 1580 mm roughing mill R2 of a steel plant during the hot-continuous-rolling process. This paper established a three-dimensional elastic-plastic dynamic coupling model of the rolls and slab using the finite element (FE) analysis software ABAQUS/Explicit. In addition, the paper used a data analysis method based on the node-set coordinate output. By balancing the relationship between computational precision and efficiency, the study found the FE model to run stably. Using the proposed model, the paper systematically investigated the influence of cross position and angle on the camber, slab wedge, and amount of rolling force under different conditions. Based on the FE results, the paper then characterized the influence law for the occurrence of a cross roll with respect to bearing clearance and slab camber. Numerical examples demonstrate that the relationship between the camber and cross-angle position is linear, and that between the slab camber and clearance is a quadratic curve.

Keywords

• hot rough rolling
• camber
• crossed roller
• finite element
• analysis of influence