Study Of Cold Strip Rolling Mill Equipment Defects Effect On Strip Shape

Plate products are the main products in iron and steel industry, and they are widely used in various sectors of national economy. Plate rolling process is a complex process, which involves roll stand, roll, strip and many other relative respects. The quality precision of strip shape is an important indicator to measure product quality. In order to obtain the change law of strip with various disturbance and control factors, we must study the strip rolling process essentially. This paper study the effects of roll eccentric and running deviation on strip shape, so that we can predict and control the strip shape accurately. Running deviation on strip shape are important defects in rolling equipment defects. The usual research mainly study the control system for the cold strip rolling mill. However, the study of the effects on the rolling mill equipment still needs to be explored.This paper study of the effects of rolling mill equipment defects on strip shape. At first, we establish a three-dimensional model of roll system and strip. We do dynamic simulation and analysis on the rolling process by using the finite element software ANSYS LS-DYNA. Secondly, we research on the defect of roll eccentric. We analyze the change law of strip, which is effected by different roll velocity, friction coefficient, reduction rate, and strip thickness, under the condition of work roll elliptic eccentric and back-up roll elliptic eccentric. Finally, this paper study the phenomenon of strip rolling running deviation under different asymmetry inducements. We analyze the mechanism of strip rolling running deviation. We simulate the effects of three factors to strip. The direction of strip running deviation is the thicker side when the strip has thickness. The direction of strip running deviation is the smaller roll gap side when the work roll has roll gap.Through the analysis, we determine the main cause of strip rolling running deviation and roll eccentricity. The research results show that the roll force increases with the increase of roll velocity, friction coefficient and strip thickness, and the roll force decreases with the increase of reduction rate. The variation of roll force under back-up roll eccentric is identical to the work roll. The maximum roll force under work roll eccentric and not eccentric are respectively3200KN and2000KN, differ1200KN. The maximum roll force under back-up roll eccentric and not eccentric are respectively2850KN and2200KN, differ650KN. We can come to the result that the elastic work roll has reduced the effect of back-up roll eccentric on plate shape. The analysis results show that the running deviation under the workpiece original offest is smaller than the other two factors.It provides the favorable theoretical guidance and technical support for system structure optimization design and technical parameters selection. Its also does a great help to improve product quality and increas production of steel strip. So, the research has important theoretical and practical significance.