Causes of wrong edges of large-diameter spiral steel pipes (SSAW):
In the production of large-diameter spiral steel pipes, misalignment occurs from time to time, and there are many influencing factors. In production practice, steel pipes are often degraded due to dry misalignment and out-of-tolerance. Therefore, it is necessary to analyze the causes of wrong edges of large-diameter spiral steel pipes and preventive measures.
1. The sickle bend of the steel belt is the most important factor causing the wrong edge of the steel pipe.
In the forming of spiral welded pipes, the sickle bend of the steel strip will continuously change the forming angle, resulting in the change of the weld gap, resulting in seams, staggered edges and even overlapping edges. The quality of the steel pipe is seriously affected. Therefore, observe the sickle bend of the steel strip after uncoiling. By controlling the vertical roll, the disc shear can cut off part of the sickle bend. The continuous control and correction of the forming angle are to reduce the sickle bend of the steel strip during the production process. An effective way to produce wrong sides.
2. Due to the poor shape and dimensional accuracy of the head and tail of the untrimmed steel strip, it is easy to cause the steel strip to bend hard and cause the wrong side to be caused by the butt joint.
3. When the reinforcement of the welding seam of the head and tail butt welding of the steel strip is large, if the over-forming is not handled properly, it is easy to cause a large misalignment.
4. The poor condition of the edge of the steel strip is another important reason for the wrong edge.