It is strictly forbidden to adjust the three-line difference by lifting the east-west crossbeam:
a. Due to the substantial difference in process control between three-cutting and two-cutting, the adjustment of the lifting beam will cause the size of the centerline finished product to change.
b. Improper relationship between finishing rolling and pulling will also cause the size of the finished product to change, especially the pulling of steel between 8#, 9# and 2# sets will cause the size of the centerline to change.
c. The difficulty of adjusting the three-line difference lies in the adjustment of the centerline difference (the premise is that the guide, crossbeam, and the east-west roll gap of the roller are installed correctly), and the tightness of the K3, K4, and K5 inlets directly affects the centerline difference.
d. The alignment of the K2 inlet directly affects the height of the three steels on the 3# set, and whether the width and shape changes of the K2 material type can be smoothly introduced into K1.
2. Precautions for the use of process control guides.
a. The pre-twist clearance of K4 is generally 1-2mm larger than the incoming material.
b. The clearance of the K3 outlet slitting wheel is 4-6mm.
c. The K3 and K4 inlets must ensure that the guide is adjusted to the positive rolling groove. When adjusting the three-line difference during rolling, it is strictly forbidden to adjust the K3 inlet guide. Once the K3 guide is installed with deviation, six heads will be formed during the cutting process, resulting in failure of the next pass.
d. K5 material type misalignment will lead to poor clamping of the K4 inlet, resulting in uneven cutting, and K5 material type dissatisfaction will lead to quality problems of the midline finished product.