Abstract: In order to deal with the problem of up-down and left-right asymmetry that may occur up in the four-roll mill work process, on the basis of a large number of field trials and theoretical study and fully integrating the process characteristics of the equipment and asymmetric state rolling of the four-roll mill and considering the asymmetry of up-down and left-right, the model of elastic deformation of the roll system is used to establish a set of plate-shaped model which suits for four-roll mill when it works. The corresponding analysis and control software of the strip shape is also drawn up. It can quantitative forecast not only effects caused alone or comprehensively by asymmetry factors such as strip drift, asymmetric roller type, rolling centerline and roll not coincidence, asymmetric centerline bending roll, asymmetric motion of roll, but also effects caused alone or comprehensively by symmetrical factors such as symmetric bending roll, symmetric motion of roll and tilting roller on the influence of the finished product plate shape. The model and software is directly applied to the analysis and control of the shape of Meigang 1420 double frame flat plate to improve the shape quality of finished products. Now the closed rate of strip shape has reduced from 2.5% before to less than 0.5% .It has created unit large economic benefits and has further application value.

Key words: Asymmetric state rolling, Elastic deformation of the roll system, Four-high mill, Shape