Stiffness modulus of stands in finishing group of continuous wide-strip hot rolling mill

Stiffness modulus is an important technical parameter of each four-high stand of continuous wide-strip hot rolling mill and characterizes the roll force that causes elastic deformation of all structural elements of the working stand in the assembly. Accuracy of deviations of longitudinal and widthwise profile of hot-rolled strips and quality of sheet products directly depends on reliability of determination of such parameter at the design stage of efficient technological rolling schedule. After review of classical methods for calculating elastic deformations of four-high stands based on the laws of the elasticity theory and modern publications, it was concluded that it is necessary to take into account the dynamic component when determining the stiffness modulus of the working stands of hot and cold rolling mills. Lack of record-keeping above the specified component entails significant errors in the alignment of the roll gaps at the stage of mill setting for rolling the strips of the required final thickness. In this work, we studied the stiffness modulus of the finishing stands of the operating continuous wide-strip mill, taking into account their constructional features in the production of hot-rolled strips of various sheet gauge of low-carbon steels, mainly intended for further cold rolling. When analyzing experimental data, reliable regression equations were obtained that allow taking into account the effect of the rolled strip width on the stiffness modulus of stands. The results of investigations are presented in graphical and tabular form, demonstrating the change in the stiffness modulus for different mill stands. The results allow us to design and make changes to the existing hot rolling modes in order to ensure the required accuracy of the longitudinal and widthwise profile of hot-rolled strips.