Forming of spiral steel pipe

The spiral steel pipe is formed into a spiral of hot-rolled strip steel, and the spiral steel pipe manufacturer uses the joint and seam welding of submerged arc automatic welding to form a spiral steel pipe (also called spiral steel pipe, spiral steel pipe).

Due to the following reasons, it can be widely used in the production of large-diameter spiral steel pipes:

1.Easy to change the size, suitable for small batch and multi-variety spiral steel pipe production;

2.Because it is continuously formed, the specified length of the spiral steel pipe is not limited;

3.As long as the forming angle is changed, it can be used to produce all kinds of spiral steel pipe diameters with the same width of strip steel;

4.The welded spiral is evenly distributed on the entire circumference of the spiral steel pipe, so the dimensional accuracy, high strength and high quality of the spiral steel pipe are high.

Compared with spiral steel pipe and straight seam pipe

The length of the screw carbon steel weld is longer than the straight seam, such as the length is L, and the weld length is L/cosine. For a long time, there has been endless debate about which spiral steel pipe is better than the straight seam pipe, especially the UOE pipe. With the development of spiral steel pipe manufacturing technology to this day, we should comprehensively and correctly evaluate and compare, and we have a new understanding of the problem of spiral steel pipe weld length.

First, because the defect is parallel to the weld, the spiral steel pipe is a welding defect of “oblique defect”.

Secondly, during use, the direction of the principal stress of the spiral steel pipe, that is, the equivalent length in the direction of the steel pipe axis is smaller than that of the straight seam pipe; because the pipeline steel is rolled steel plate, the anisotropy of impact toughness is large, and the CVN value along the rolling direction is 3 times higher than the CVN value perpendicular to the rolling direction.
The principal stress has the lowest impact resistance of the vertical pipe in the direction, while the spiral steel pipe and the straight seam steel pipe have the lowest impact resistance of the staggered pipe, and the disadvantage of the spiral steel pipe weld length is transformed into an advantage.