Submerged arc steel pipe welding control measures:Submerged arc steel pipe has become the steel pipe for large-scale oil and gas transportation projects at home and abroad due to its large wall thickness, good material, and stable processing technology. In large-diameter submerged arc steel pipe wel

Pre-welding of straight seam steel pipes: Pre-welding includes joints and welds.1. There is no wrong edge or the wrong edge is smaller than the specified value. Generally, the amount of the wrong edge is ≤8% of the plate thickness, and the maximum is not more than 1.5mm.2. It is necessary to ensure

1. MetallographyThe metallographic method is the main method to distinguish between welded steel pipe and seamless steel pipe. There is no welding material added to the high-frequency resistance welded steel pipe, so the welded seam in the welded steel pipe is very narrow. If the method of rough gri

1. Welding processIn the welding process, the welding method of the spiral steel pipe and the straight seam welded pipe is the same, but the straight seam welded pipe will inevitably have many T-shaped welds, so the probability of welding defects is greatly increased, and the welding residual stress