Twenty high is a high-precision rolling mill. The shape of rolled plate is affected by the factors such as stand, electric appliance, crimping, roll system, raw material and operation.

Among these factors, the wear and deformation of the frame and the straightness of the roller system are equivalent to the skeleton of human body and the foundation of high-rise buildings, which are the premise of producing high-quality plate shape. Without the flat roller system as support, all the subsequent operations are in vain, and the shape quality will not be improved.

The causes of the roll system are as follows:

1. The inner hole of the frame plum blossom appears uneven depression.

2. Long term installation wear and serious cone angle of locking plate lead to included angle of roll system.

3. When two or more mills use saddles interchangeably, there is a big height difference of saddle wear due to the different deformation of the inner hole and the different long-term adjustment mode.

4. The backing bearing is not matched in strict accordance with the requirements, and the accuracy deviation is large.

5. The mandrel is worn and deformed.

6. Straightness deviation of intermediate roll and work roll.

In addition to the fact that the deformation of the frame itself is difficult to control in daily life, the other causes are caused by improper maintenance and operation.

Here is how to maintain the accuracy of the roll system:

The first step is to start with bearing height matching and rotation accuracy. To ensure reasonable height matching and high rotation accuracy is the premise to ensure balanced stress on mandrel, saddle and corresponding plum blossom hole, and to reduce wear and deformation, and is also the "maintenance way" of roller system!

The second step is to maintain the mandrel. The mandrel should be replaced regularly, for example, roll a is replaced by roll D, and roll D is replaced by roll C after a period of time. In this way, the long-term wear of the same area on the mandrel can be prevented.

The third step is to test the saddle regularly. In the rolling process, due to the deviation of the local adjustment amount, the stress on the saddle will be uneven. If the inertia adjustment mode is adopted, the saddle height deviation will be caused. Timely changing the higher saddle to the position with the largest adjustment range can not only reduce the adjustment range, but also balance the saddle height on the same roller system, and maintain a small height deviation for a long time.

Combined with the grinding accuracy of intermediate roll and work roll, the flatness of roll system can be restored as new, which can become the firm foundation to ensure the shape quality and provide guarantee for subsequent operation.