Adjustment of the roll gap
Whether the roll gap adjustment is correct or not directly affects the stability of the rolling process, and also determines the size of the rolled piece exit. The basis for judging the quality of roll gap adjustment is: the rolling process is stable, the size of the rolled piece is qualified, the shape of the rolled piece is normal, and the reduction is evenly distributed.
There are three specific operations:
1) After a certain amount of rolling, the roll gap adjustment (compensation adjustment) is used to compensate for the wear of the rolling groove.
2) The roll gap can be flexibly adjusted according to the size of the rolled piece and the change of the rolled steel or process parameters.
3) Axial adjustment (wrong roll, roll shifting).
Tension setting and adjustment
The size of the tension affects the size of the rolled piece. Requirements for it: the tension of each frame is constant and constant, and the influence of tension fluctuation on the size of the rolled piece and the rolling process is reduced.
There are three ways to check:
1) Knock the rolled piece with tools such as iron rods, and check the tension between the two racks to judge its size
2) Observe the width of the unrolled part on both sides of the rolled piece to judge its size (the greater the width change, the greater the tension).
3) It can also be judged by the change of the motor load current.
Adjusting the tension is mainly realized by adjusting the speed of the rolling mill. However, before realizing this process, it must be ensured that the height and dimensions of the rolled pieces of each rolling mill meet the technological requirements. Do not adjust the roll gap at the same time as the speed is adjusted, which will easily cause confusion in the adjustment.
Adjustment Criteria for Finishing Rolling Mill
1) The 20#～27# rolling mills cannot be adjusted at will. After adjustment, the micro-tension between each frame will be destroyed, resulting in fluctuations in dimensional accuracy and easy to cause steel stacking accidents.
2) When the size of the finished product is unstable, the guide should be checked. When the height is larger and the width is larger, first adjust 19# and then 28#.
3) When the size of the finished product fluctuates greatly, the material type of each flight should be checked (mainly the lead test rod).
4) Check the pre-finishing material type.