The first, wall unevenness of steel pipe (180 degrees eccentric)
1. The tube is cut and cut
2. Billet heating uneven or centering bias
3. The perforation roller does not coincide with the roll or the roll center and the perforation center are inconsistent
4. The mandrel is bent or the center of the roller is offset from the rolling center or the roller frame is in poor condition
5. Personnel operation problems (open open roller frame in advance)
The second. rough inside and outside of the capillary
1. Check whether the surface of the tube cracks, folding, pits, inclusions, tube according to the process requirements of uniform heating.
2. Check the wear of the three rolls and adjust the reduction (head position). Control roll cooling water.
3. Replace the wear of the head (nose, perforation part of the cone) to ensure that the pressure of cooling water.
