The cause of the deformation of rectangular tube welding

In the welding deformation theory, we can know that the large size of the weld will led to the greater deformation, welding the same size, the welding heat input on large, can lead to large deformation, the long seam welding, welding deformation will be small, asymmetrical seam or asymmetrical arrangement of the welding seam deviation will cause more serious to severe deformation.

Welding specifications through process analysis and process test in determining square tube and rectangular tube butt weld double carbon dioxide gas shielded arc welding is a welding current of the first layer 200-250A, the second layer of the arc voltage is 24-26V, which is the first layer of weld process requirements must be able to ensure good welding, to form, welding current, arc voltage, wire feed speed and welding equipment needs to be more regulation.

Welding sequence to reduce distortion rectangle, welding sequence should be in accordance with the following principles: start with middle to both sides symmetrical hierarchical segmentation welding, diffusion and it is a good stress release, to avoid stress in welding production complex, by swinging welding, welding at the beginning of the formation of plastic deformation of the narrow region only once, because the continuous swing and heat input welding, the heated area is too large, large compressive plastic deformation, so large deformation of welding shrinkage, when welding STAGED because each section is very small, the heat is small, each layer is divided into several sections, so each jump welding welding, basically in the cold temperature field reconstruction, each in a narrow corresponding to the plastic deformation of the longitudinal weld layered linear shrinkage, rather than by filling the continuous time swinging the welding deformation.

Weled steel pipe specification, Standard and identification

Welded steel pipe (steel pipe manufactured with a weld) is a tubular product made out of flat plates, known as skelp, that are formed, bent and prepared for welding.