Experimental study of electric drives used in rolling mills during asymmetric rolling of sheets and stripes

Abstract

The authors review the basic principles of organizing the process of asymmetric rolling (AR) and the results of its application on single- and five-stand mills. The main positive qualities of the process, such as improved physical and mechanical properties, and enhanced strip microstructure, are shown. The limitations of the maximum values of the asymmetry factor are justified: for multi-stand mills with an individual drive, this parameter depends on the degree of impact of the local control systems (e.g., thickness, tension, load division), and typically does not exceed 1.15. At the same time, attention should be paid to the possibility of switching the driven roll drive to the generator mode, and the ensuing consequences. For the laboratory and industrial mill 400, the maximum value of high-speed asymmetry is determined by the power of the driving roll motor and the power circuit type of the driven roll converter in the generator mode. Oscillograms of the driving roll motor currents are provided, confirming an uneven nature of deformation along the length of the strip in case of significant asymmetry.