Ultrasonic testing of welded pipe inspection process

Welded steel pipe, also known as welded pipe, steel sheet or strip is molded after curling welded steel pipe. Welded steel pipe production process is simple, high production efficiency, variety specifications, equipment owned small, but generally less than seamless strength. Since the 1930s, along with high-quality strip steel rolling production as well as the rapid development of welding and inspection technology, continuously improve the quality welds, welded steel pipe increasing varieties and specifications, and in more and more areas instead of a non- pipe joints. Press the seam welded steel pipe into the form of longitudinally and spirally welded pipe.

Longitudinal production process is simple, high efficiency, low cost, rapid development. Spiral Welded Longitudinal generally higher than, can narrow the billet production of large diameter steel pipe, you can also use the same width of the billet production of different pipe diameters. But with the same length of straight pipe joints than weld length of 30 to 100%, and lower production rate. Therefore, the smaller diameter pipe is mostly a straight seam welded, large diameter spiral welded pipe is mostly used. Although welded pipe production line is quality assurance, but also have some small problems inevitably arise, so pipe testing done at the factory areas is essential, it can be said is crucial.

General common pipe weld defects: pores, slag, incomplete penetration, lack of fusion and cracks. So far there is not a mature approach to the nature of defects accurately judge, but according to a defect on the screen to get the shape of the wave and the reflected wave height changes combined with the location of defects and welding a comprehensive assessment of the defect judgment.