Improve the accuracy of seamless pipe wall thickness-Boiler Tubes,Heat-Exchanger Tubes,Superheater Tubes,Supplier,Beite

Improve the accuracy of seamless pipe wall thickness

Measures to improve the accuracy of seamless steel pipe wall thickness

The control of the wall thickness of seamless steel pipes is a difficult point in the production of steel pipes. The measures to improve the wall thickness accuracy in production mainly include the following aspects:

1. Tube billet heating

Heating must be uniform, and rapid temperature rise and fall are prohibited. Each time the temperature rise and fall should be kept steady and slow, and the maximum temperature rise and fall should not exceed 30°C.

2. Centering roller

Determine whether the centering roller is installed in place, adjust the center, opening angle and the opening size of the relevant core roller to be consistent, and the center of the core roller should be on the rolling line.

3. Rolling center line

Ensure that the rolling centerline of the piercing machine is consistent with the centerline of the piercing trolley, avoiding "up rolling" or "down rolling", so that the tube billet maintains uniform force during piercing.

4. Rolling tools

The worn plugs, guide plates, rolls and other rolling tools should be replaced in time.

5. Installation of rolling tools

The center of roll pitch and lead must be on the rolling line. Ensure that the centerline of the guide and roll pitch is on the piercing and rolling centerline, that is, the upper and lower roll pitches are equal, and the left and right guide pitches are equal.

6. Perforated ejector

Perforated ejector rods generally choose thick-walled seamless steel pipes with outer diameter of Φ108mm-Φ114mm, wall thickness ≥25mm, and uniform wall thickness.

7. Rolling mill mandrel

The mandrel should be processed by a thick-walled tube with a thicker wall. For the mandrel with a smaller specification, a solid blank can be used instead. Thick-walled pipes and solid blanks with uniform wall thickness can greatly reduce the probability of bending deformation of the mandrel, and can effectively improve the wall thickness accuracy of the steel pipe.

8. The accuracy of the mandrel

The length of the mandrel is relatively large. Generally, the outer diameter of the mandrel is turned first and then the weld is broken, or the long material is directly turned and formed. The outer machining accuracy of the mandrel is controlled within ±0.1mm, and the deviation of the straightness of the mandrel does not exceed 5mm. When welding, a precision-machined pin is inserted between the two core rods for positioning to prevent the overall straightness deviation caused by welding from being too large.

9. Improve the process

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