Measures to reduce the sticking phenomenon of steel pipe billet rolling

When the billet is rolled, sometimes the safety mortar breaks and the stick stick phenomenon occurs, which leads to the shutdown accident and seriously affects the smooth production. The analysis considers the following reasons:

1. Capillary size factor. The large capillary tube size increases the continuous rolling load and increases the rolling force, which leads to broken rods.

2. Over-pressure factor of roll gap. The over-pressure of the roll gap increases the rolling reduction, which leads to an increase in rolling force, which greatly increases the probability of broken rods.

3. Large difference between the inside and outside of the roll gap. The difference between the inside and outside of the roll gap is large, the rolling force on the side with the large roll gap is small, and the rolling force on the side with the small roll gap is large. in

In the case of a set rolling reduction, the side where the rolling force is too large tends to break.

4. Improper adjustment of roll speed. Improper adjustment of the rotation speed of the adjacent frame rolls will cause stacking and pulling steel. Pulling steel will reduce the rolling force, stacking steel will increase the rolling force, and the rolling force will increase the probability of breaking the rod.

The improved method for this is:

1. Capillary sampling. When the specifications of the core rod change ≥ 5mm, capillary sampling must be proposed, and adjustment must be made according to the actual size of the capillary. When the core rod specification changes <5mm, the outer diameter of the capillary must be measured before the rod removal chain, and adjusted according to the outer diameter of the capillary.

2. Measure roll gap in time. After multiple adjustments, due to the cumulative adjustment error, the roll production between the roll gap and the actual roll gap may be too large, resulting in a high rolling force. For this reason, the actual roll gap must be measured once during the handover. The actual roll gap must be measured.

3. Measure the inner and outer roll gap in time. Due to the assembly accuracy of the roll itself, the gap between the inner and outer roll gaps of the continuous roll is often too large. Therefore, use the lead block to measure the inner and outer roll gaps of the rolls in time. If the inner and outer roll gaps are too poor, replace the rolls immediately

4.Standard speed adjustment. It is required that the difference in the speed correction value between adjacent frames should not be greater than 3%, to avoid over-stacking and pulling, which will cause the broken mortar and stick to stop.