Improvement of Dynamic Strip Tension Control Model for Threading-in Rolling on Cold Tandem Mill

To solve both the problems of unstable tension and difficult start in threading-in process on 1420 tandem cold mill, a model of strip tension fluctuation in threading-in process was built,with a formula of static deviation of strip tension. The factors influencing on strip tension were analyzed according to tension control and continuous rolling theories. The results indicate that using P-controller to adjust tension could make tension fluctuate; the tension stability and quality of tension creation could be improved by increasing proportion coefficient of controller,reducing presetting velocity on stand No1 and rolling force on each stand.The model was applied in tension optimization in threading-in process of 1420 tandem cold mill, with satisfactory results.