The main reasons for this phenomenon are as follows:
1. There are defects in the crescent design in the K1 hole type, which makes it difficult for the steel material to be removed from the groove and thus hit the exit guide plate.
2. The K2 hole slot is designed too large, and the slitting belt cannot be processed well.
3. The material shape control is inaccurate. The K4 frame is poorly filled, or the shape of the K3 frame material is too small. The front end of the steel material is seriously asymmetric after slitting, the K2 frame is deformed unevenly, and the cutting belt is poorly processed and enters the top outlet of the K1 frame.
4. Or the shape of the material in the previous pass of the finishing mill is too large, and the deformation of K1 is seriously uneven, resulting in the top outlet phenomenon.
5. The size of the rolled piece before the finishing rolling is not suitable, and the gap control of the K3 or K4 guide rollers is not suitable, resulting in the head size being too large or too small, resulting in the top outlet of the K1 frame.
6. The high temperature at the slitting belt will also make it difficult for the K1 frame to slit and thus hit the exit guide plate.
7. The K1 exit guide plate is far away from the roller, and the rolled piece that is out of the hole groove will hit the exit without control.
8. The guide beam of the K1 rolling mill is not assembled and aligned according to the standard requirements.
9. The slitting guide is not assembled as required, or the slitting wheel is eccentric in the wrong direction or the direction is not uniform.
10. The torsion angle of the K2 frame exit may not be adjusted in place.
11. The rolling groove is severely worn.
12. The gap between the roller connecting shaft is too large.
Solution to the K1 knocking exit fault:
1. Optimize the hole system and scientifically and reasonably distribute the reduction amount of each pass.
2. During the production process, the mill adjuster must strictly follow the process requirements and control the size of the rolled piece for each pass.
3. Improve the assembly and installation level of the rolling mill guides, focus on installing the rolling mill guides of K3-K4, ensure the rigidity and axial stability of the rolling mill; strictly do a good job of pre-adjusting and installing the guides.
4. Pay attention to the cooling of the slit strip.
5. Improve the form and inner cavity size of the K1 outlet guide, control it within a suitable range, make the tongue tip as close to the deformation area as possible, and improve the guiding performance.