Changsha Xiangjia Metal Materical Co., Ltd.

  SSAW steel pipe : It is rolled by low-carbon structural steel or low-alloy structural steel strip at helix angle to form a tube blank, and then welding the tube seam. The specifications are expressed by outer diameter * wall thickness, and the welded pipe shall be ensured that the hydraulic test, the tensile strength of the weld and the cold bending performance must meet the requirements. Advantages of SSAW steel pipe: 1. The same width of strip steel can produce different diameter steel pipes 2. Under the same pressure conditions, the stress of the sprial welded seam is smaller than that of the straight seam, which is 75% to 90% that of the straight seam welded pipe, so it can withstand greater pressure. Compared with the LSAW steel pipe of the same outer diameter, the wall thickness can be reduced by 10% to 25% under the same pressure. 3. The size is accurate, the diameter tolerance does not exceed 0.12%, the deflection is less than 1/2000, and the ovality is less than 1%. Gene...

 Defects that are easy to produce in the welding pipe are pores, hot cracks and undercuts. 1. Bubbles. Bubbles mostly occur in the center of the weld bead. Because hydrogen is hidden in the weld metal in the form of bubbles. Therefore, the measure to eliminate this defect is to remove the rust, oil, moisture and moisture of the welding wire and the weld. Secondly, the flux must be dried well to remove moisture. In addition, it is also very effective to increase the current, reduce the welding speed, and slow down the solidification speed of the molten metal. 2. Sulfur crack (crack caused by sulfur). When welding plates with a strong sulfur segregation zone (especially soft boiling steel), the sulfide in the sulfur segregation zone enters the weld metal to produce cracks. The reason is that the sulfur segregation zone contains low-melting iron sulfide and the presence of hydrogen in steel. Therefore, in order to prevent this, it is effective to use semi-killed steel or killed steel ...

After the production of  SSAW steel pipe , the cross-section should be round. The standard of ovality is that the large outer diameter must not be 1% larger than the nominal outer diameter, and the small outer diameter must not be 1% smaller than the nominal outer diameter. When the port of the SSAW steel pipe appears elliptical, it cannot be connected during butt welding in the construction. So what kind of SSAW steel pipe easy to ellipse? When the end of SSAW steel pipe have welded seam that needs fixed, it is prone to ellipse. Another reason is that the SSAW steel pipe of the butt joint plate is prone to ellipse. When pipe ends with repair welding or a large number of repair welding areas and butt joints on the pipe, the ovality of the spiral welded pipe must be measured carefully, and if it exceeds the standard then need to repair. ​ How to deal with the elliptical defect of the SSAW steel pipe? Usually, we use lifting jack. After measuring the small diameter, use the jack to p...