Automatic Tension Control in the Continuous Roughing Train of a Wide-Strip Hot-Rolling Mill

Resumo

The automatic tension control system of the three-stand continuous roughing train of the 2000 hot-rolling mill at the Magnitogorsk Metallurgical Combine is analyzed. Deviations in interstand tension that are several-fold higher than the set values and inadmissible compression are detected. The causes of poor tension control are determined, such as a large error in measured roll pressure and short response time of the system. An improved method for automatic tension control is developed. It involves combining speed-difference tension control during free rolling and static-current tension control during multi-stand rolling on three stands. A functional block diagram of the system implementing the method is considered. Experimental data obtained on the 2000 mill are presented. The basic advantages of the system that demonstrate its efficiency are indicated.