Continuous progressive diameter expansion and rounding device and method for thick-walled metal straight seam welded pipe

Abstract

The invention belongs to the technical field of diameter expansion and rounding of straight seam welded pipes, and in particular relates to a continuous and gradual diameter expansion and rounding device and method for thick-walled metal straight seam welded pipes. A thick-walled metal straight seam welded pipe continuous progressive diameter expansion and rounding device, including two bases on the left and right, a left frame and a right frame are respectively arranged on the top of the two bases on the left and right, the left frame and the corresponding The base is hinged, the upper parts of the left frame and the right frame are installed with corresponding bearing seats, and the variable-size mandrel is installed in the two bearing seats; On the size mandrel, the pipe is in contact with the work roll during the working process, and the work roll rotates to drive the pipe body to rotate. Under the pressure of the size change mandrel and the work roll, the roundness of the pipe is processed. The shaft is gradually opened to realize the diameter expansion of the pipe, and at the same time eliminate the stress difference between the inside and outside of the pipe, effectively reduce the Bauschinger effect of the pipe, and effectively reduce the residual stress inside the pipe.

Description

technical field [0001] The invention belongs to the technical field of diameter expansion and rounding of straight seam welded pipes, and in particular relates to a continuous and gradual diameter expansion and rounding device and method for thick-walled metal straight seam welded pipes. Background technique [0002] Large-diameter thick-walled straight seam welded pipe, because of the use of JCOE forming technology, its end face shape is a nearly circular polygon, and the mechanical properties of the inner and outer walls of the pipe are quite different, so it will affect the application in petrochemical, offshore engineering, oil and gas transmission, infrastructure projects, etc. Widely used in the industry. At present, the general method is to use a mechanical expanding machine to gradually expand the diameter of the submerged arc welded pipe radially through the expanding tool to ensure the roundness, straightness and dimensional accuracy, but because the cross section ...

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Problems solved by technology

At present, the general method is to use a mechanical expanding machine to gradually expand the diameter of the submerged arc welded pipe radially through the expanding tool to ensure the roundness, straightness and dimensional accuracy, but because the cross section of the expanding head is circular , so the expansion is a uniform plastic deformation. Although part of the residual stress can be eliminated, the rounding effect is still not ideal, and the mechanical expansion machine requires a large force when processing thick-walled pipes, resulting in a large equipment structure. High energy consumption and high investment

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