Enhancing Technologies of Stabilization of Mill Vibration by Mill Stabilizing Device in Hot Rolling

In hot rolling, the strips have been needed to be rolled harder and faster to obtain thinner and higher quality strips, such as high strength steel or dual phase type high strength steel and so on. As the strips move faster and are rolled harder, the larger impact force in the threading occurs and suddenly mill starts to vibrate with enormous amplitude. The larger impact force or mill vibration causes not only the reduction of life time of the mechanical parts but also reduction of operational stability and manufacturing efficiency. In order to solve these issues, Mill Stabilizing Device which consists of the hydraulic cylinder with orifices has been put into the practical use. Recently, it is strongly required that much harder and thinner strips are needed to be rolled and so it is necessary to enhance the damping effect of Mill Stabilizing Device. Installing the chamber in Mill Stabilizing Device is proposed and the simulation was carried out to optimize the chamber size and orifice size. The verification test was carried out in the production line and it is obtained that mill vibration was drastically reduced by Mill Stabilizing Device with the chamber.