Threeway Steel Co.,Ltd is a world-class SSAW steel pipe manufacturer,one of the largest subsidiary in SHINESTAR GROUP.
Double wire, spiral steel pipe（SSAW) is double-sided submerged arc welding arc welding( dsaw) under the flux layer method, the use of welding wire and flux in the solder layer between the arc produced under the burning heat flux and base metal melting metal wire to form. For the following reasons it is widely used in the production of large-diameter steel pipe:
1, just change the shape angle, you can use the same width of the strip steel production of various caliber;
2, because it is a continuous bending, pipe cut to length so the length is unlimited;
3, spiral weld evenly distributed across the pipe circumference, so the size of pipe, high precision, high intensity;
4, easy to change the size, suitable for small quantity and variety of steel production.
Spiral weld seam than the straight pipe length, such as pipe length L, then the weld length is L / cos (θ). For a long time debating the spiral and straight seam pipe, especially compared with the UOE pipe superior who issues. Spiral pipe manufacturing technology of today, we should be fully and correctly evaluate and compare, the idea of a long spiral weld problems.
First, since the defect parallel to the weld, so the spiral, its seam defect is "inclined defects." In use, the main pipe stress direction, the direction of the axis of the pipe than the equivalent length of straight seam tube defects is small; Second, the pipeline are rolled steel, have a greater impact toughness anisotropy, along the rolling direction the CVN value is comparable to the direction perpendicular to the rolling three times higher CVN values. Straight seam pipe stress suffered by the main shock is precisely perpendicular to the pipe capacity of a minimum of direction, while the spiral is the ability to stagger the pipe a minimum of impact direction, so that the disadvantages of a long spiral weld transformed into advantages.
