A method for forming straight seam welded pipe

Abstract

The invention provides a forming method of a straight seam welded pipe. Before a flat plate strip is bent and formed, the plate strip is rolled to be in a shape of a corrugated plate through a rollingprocess, the transverse stress of the plate strip is improved, broadsiding of the plate strip is promoted, and longitudinal deformation of the edge of the plate strip can be reduced. In addition, thecorrugation curvature radius of the edge of the plate strip is close to the extrusion roller hole pattern radius or the finished welded pipe radius, a pair of horizontal rollers are adopted for flattening the middle part of the corrugated plate, and then a straight part is bent and formed into a pipe blank. In the above process, the edge of the bent plate strip is always wavy before the hole pattern is closed, the three-dimensional support force is improved, longitudinal draw is better reduced, and side waves and bumps caused by the residual stress in the welding process can be avoided. The operation method is simple, belongs to physical improvements, is strong in versatility, is easy to improve on an original organic type and is economical and practical.

Description

technical field [0001] The invention belongs to the field of plate roll forming, and in particular relates to a forming method for using plate to manufacture straight seam welded pipes. Background technique [0002] Forming technology is the core of welded pipe production technology and the key to producing high-quality welded pipes. Forming technology determines the output, variety, quality and consumption of welded pipes, which is a matter of great concern to the design and use of welded pipe equipment. The forming methods of straight seam pipe mainly include: roll forming, row roll forming, FFX forming, UOE forming, etc. [0003] Roll forming is an important field of deep processing of sheet metal. It is a plastic processing method that gradually bends and deforms the blank through a forming unit composed of multi-section forming rolls with certain surface shapes, thereby obtaining a uniform cross-section product. Longitudinal welded pipe is one of its main products. Co...

AI Technical Summary

Problems solved by technology

When the tensile stress is large or the tensile deformation is large, the deformation cannot be completely eliminated after the external force is removed, so that a large residual deformation occurs, and the formed tube will produce edge waves or bulges at the edge, which is not large. The bulge can also be corrected through the closed hole of the guide ring, but the bulge caused by the excessive elongation of the edge is not easy to eliminate. Entering the welding unit will make the welding unstable and affect the welding quality, and even the welding cannot be performed.

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