The wrong side of the high frequency longitudinal welded pipe
is the most common problem of pre welding. The wrong side of the oversize will directly lead to the deterioration of the steel or scrap. Therefore, pre welding requires strict control of the wrong amount. Generally speaking, when the whole root or half of the tube billet is wrong, it is due to:
1, the slit adjustment is not in place (seams);
2, the adjustment of the joint roller is not in place (the angle of the roller is not right, or the center line of the tube is the axis, the left and right pressure rolls are asymmetrical, or the radial extension of the relative pressure roller is not consistent), and the pressure free round is not.
3, the pre bending is not pre bending, and there is a straight edge phenomenon.
When the head or tail of pipe is wrong, it is usually due to:
1, the position of the import and export roll is not right;
2, the ring frame center is not right;
3, the pressure of combined roller is not good, and the position of individual roller is deviant.
4, the forming is not good.
5, the width of the slit is more than 150mm.
6, the pressure fluctuation caused by the hydraulic system.