Common surface defects of welded steel pipe:
(1) Layered steel
Layered wall steel pipe means that the cross section is divided into two layers, and the exposed steel plate surface presents vertical cracks in layers. Some of the internal and external surfaces of the display steel are locally depressed or bulged, and the delamination appears to rise suddenly, and the depressed or warped in and out of the weld seam.
(2) sticky scar
Pipeline viscous scar refers to the internal and external surface of large steel adherent plaque scar.
(3) hole
Pipeline through hole refers to the existence of double holes in local steel pipe.
(4) Open welding
Welded steel pipe openings are shown through long cracks or parts of the steel welds.
(5) Local lap welding
Welded steel pipe refers to the local arc welding on the external surface of steel pipe.
(6) Welding trench
Pipeline welding groove occurs on the outer surface of steel pipe through long groove weld.
(7) Welding collapse
Welded steel pipe collapse refers to the outer surface of weld metal skeleton displayed through long grooves, and the corresponding convex surface.
(8) Pipe joint dislocation
The dislocation of steel pipe joints refers to the phenomenon of staggering up and down when steel pipe is welded.