Measures To Improve The Accuracy Of Steel Pipe Wall Thickness

The control of steel pipe wall thickness is a difficult point in steel pipe production, and measures to improve wall thickness accuracy in production mainly include the following aspects:

1. Tube billet heating

Heating should be uniform, and rapid temperature changes are prohibited. Each temperature rise and fall should be kept steady and slow, with a maximum rise and fall temperature not exceeding 30℃.

2. Centering roller

Confirm whether the centering roller is installed properly, adjust the center, opening angle, and opening size of the relevant core holding roller to be consistent, and ensure that the center of the core holding roller is on the rolling line.

3. Rolling centerline

Ensure that the centerline of the perforating machine is consistent with the centerline of the perforating trolley, avoiding "upward rolling" or "downward rolling", so that the tube blank maintains uniform force during perforation.

4. Rolling tools

For worn rolling tools such as tips, guides, and rollers, they should be replaced in a timely manner.

5. Installation of rolling tools

The center of the roll distance and guide distance must be on the rolling line. Ensure that the centerline of the guide distance and roll distance is on the centerline of the perforation rolling, that is, the upper and lower roll distances are equal, and the left and right guide distances are equal.

6. Perforated top rod

Perforated top rods generally choose thick walled pipes with an outer diameter of Φ 108mm - Φ 114mm, a wall thickness requirement of ≥ 25mm, and uniform wall thickness.

7. Rolling mill core rod

The core rod should be processed using thick walled pipes with thicker walls. For smaller core rods, solid blanks can be used instead. Thick walled pipes and solid billets with uniform wall thickness can significantly reduce the probability of core rod bending deformation and effectively improve the wall thickness accuracy of steel pipes.

8. Precision of core rod

The length and thinness of the core rod are relatively large. Generally, the outer diameter of the core rod is machined first and then welded with a break, or the long material is directly turned into shape. The external machining accuracy of the core rod is controlled within ± 0.1mm, and the straightness deviation of the core rod does not exceed 5mm. During welding, a precision machined pin is inserted between the two core rods for positioning to prevent excessive overall straightness deviation caused by welding.

9. Improve the process

Improve the process to prevent intermediate thinning and wall thickness increase beyond the control range, and enhance the accuracy of wall thickness.