Method for straightening straight seam steel pipe

First, the straight seam steel pipe is bent in the same direction as the weld

Reason: Insufficient normalizing of the weld seam, thermal stress exists on the side of the pipe close to the weld seam, so it will bend in one direction after cooling.

Solution:

1) Adjust the middle roller to appropriately increase the deflection curve;

2) Straighten twice;

3) When straightening is not possible, the entire tube is tempered.

Second, irregular bending of straight seam steel pipes

the reason:

1) The pressure between the three rollers is inconsistent;

2) The straightening roller is worn out.

Solution: Check whether the upper straightening roller is loose and use a sample bar to straighten the length of the contact line between the three passes.

Third, the length of the straight seam steel pipe is greatly shortened

Reason: The rolling angle between the three straightening rolls is too different; the straightening pressure is large.

Solution: Adjust the roll pressure angle to be as consistent as possible; adjust the straightening pressure appropriately.

Fourth, one end of the straight seam steel pipe is bent

Reason: The distance between the rollers is too large.

Solution: Choose a straightening machine with a smaller pitch that adapts to the corresponding pipe diameter.

Fifth, the straight seam steel pipe head is not round

Reason: The contact phase distribution between the three straightening rollers is improper or coincident, and the roller pressure is too high.

Solution: Adjust the angle between the roller and the roller appropriately, and adjust the pressure of the roller to the tube.