Since the 1930s, with the development of strip steel rolling production and the improvement of welding and inspection technology, the quality of welds has been continuously improved, and the variety and specifications of welded steel pipes have been increasing, and they have replaced seamless steel pipe. Welded steel pipe is divided into SSAW steel pipe and LSAW steel pipe according to the form of welding. Here we will introduce you SSAW steel pipe.
What is a SSAW steel pipe (spiral submerged arc welded steel pipe)?
SSAW steel pipe is formed by spirally bending hot-rolled strip steel, and submerged arc welding is used to weld inner and outer seams to make spiral seam steel pipes (also known as spiral welded pipes, spiral pipe spiral steel pipes). It can be widely used in the production of large diameter steel pipes for the following reasons:
1) Only if change the forming angle, steel pipes of various calibers can be produced from strips in the same width;
2) The fixed length of the steel pipe is not limited because of continuous bending forming;
3) The spiral shape of the weld seam is evenly distributed on the entire circumference of the steel pipe, so the dimensional accuracy of the steel pipe is high and the strength is high;
4) Easy to change size, suitable for small batch and multi-variety steel pipe production.Because the defects are parallel to the weld seam, for spiral tubes, the weld seam defects are oblique defects. In the process of use, the principal stress direction of the steel pipe, that is, the equivalent defect length in the axis direction of the steel pipe is smaller than that of the straight seam pipe; secondly, because the pipeline steel is a rolled steel plate, the impact toughness has a large anisotropy.
The CVN value in the rolling direction can be three times higher than the CVN value perpendicular to the rolling direction. The main stress on the straight seam pipe is exactly perpendicular to the direction of the lowest impact resistance of the pipe, while the spiral pipe staggers the direction of the lowest impact resistance of the pipe, which turns the disadvantage of the weld length of the spiral pipe into an advantage.
Changsha Xiangjia Metal Materical Co., Ltd. the Steel Pipe Division of ADTO GROUP, is one of the leading manufacturers of steel pipe in China. We supply ERW steel pipe in high quality. We supplier high qulity SSAW steel pipe in various calibers.
