Improvement measures of wall thickness precision of seamless steel pipe

Seamless steel pipe wall thickness control is the production of steel pipe difficult to improve the precision of seamless steel pipe wall thickness Production measures include the following aspects:
1, tube heating
Evenly forbid the rapid warming. Each heating and cooling remain slow and stable, the maximum temperature does not exceed the elevator 30 degrees.
2, centering roller
Determine the centering roller is installed in place, adjust the roll core to maintain center, opening degree of movement of the opening and the same size, the center of the core roll to maintain the rolling line.
3, scroll the center line
Make sure the piercer pierces the car center line and the center line to avoid "pinching" or "rolling" the tube to hold the force even when piercing.
4, rolling tools
Wear head, must be promptly replaced guide roller and rolling tools.
5, rolling tool installation
Rolling from the rolling center must be from the rolling line. Guarantee from the guide roller centerline and from the centerline into and rolling, that is, the distance between the upper and lower rollers, close to the rail.
6, piercing mandrel
Perforated Jack usually use diameter Φ108mm-Φ114mm, wall thickness and wall thickness ≥25mm uniform thick-walled tube.
7, mandrel rolling machine
In order to choose mandrel and thick-walled tube processing, you can use a smaller mandrel instead of solid billet. Thick-walled thick-walled tubes and solid billet can significantly reduce the probability of bending deformation of the mandrel, which can effectively improve the thickness accuracy of the steel pipe.
8, precision mandrel
Slender mandrel is relatively large, usually first re-welded with a car break outside diameter, or direct turning with long forming. Mandrel precision control ± 0.1mm, no more than 5mm deviation of the straight axis. During welding, insert the mandrel between the two parts of the dowel pin to prevent excessive tolerances on the total straightness during welding.
9, process improvement
Process improvement to prevent thinning of the middle of the wall thickness and increase the control over the occurrence of Haou, improve thickness accuracy.