Api 5l Psl1 Gr.B Oil Transmission Steel Tube Project LSAW Steel Pipe

Submersed arc welding (including submerged arc surfacing and electroslag surfacing, etc.) is a welding method in which the arc is burned under the flux layer.Its inherent advantages of stable welding quality, high welding productivity, no arc light and little smoke make it the main welding method in the production of pressure vessels, pipe segments, box beams and columns and other important steel structures.Although many new welding methods of high efficiency and high quality have appeared successively, the application field of submerged arc welding has not been affected at all.From the point of view of the weight share of the deposited metal in various fusion welding methods, submerged arc welding accounts for about 10% and has not changed much over the years.

When the wire is determined (usually depends on the type of steel being welded), the supporting flux becomes the key material, which directly affects the mechanical properties of the weld metal (especially the plasticity and low temperature toughness), crack resistance, welding defect incidence and welding productivity, etc.The weight ratio of welding wire to flux is welding wire: flux =1.1 ~ 1.6, depending on the type of welding joint, flux used and welding specification parameters.Compared with melting flux, sintering flux dosage is more economical, about 20% less.

UOE steel pipe: single sheet steel in the edge of pre-bending, after U forming, O forming, welding, welding, mechanical cold diameter expansion and other processes.JCOE steel pipe: according to the "J-C-O-E" pre-welding, forming, welding after cold diameter expansion and other processesHME steel pipe: it is formed according to "C-C-O" by mandle-rolling method, and then welded through cold diameter expansion and other processes.

LSAW steel pipe has a wide range of finished specifications, good toughness, plasticity, uniformity and compactness of weld, and has the advantages of large pipe diameter, thick pipe wall, high pressure resistance, low temperature resistance and strong corrosion resistance.In the construction of high strength and high quality long distance oil and gas pipelines, the required steel pipes are mostly large-diameter thick wall straight seam submerged arc welded pipes