Quality control method for high-frequency longitudinal welded pipe

Abstract

The invention discloses a quality control method for a high-frequency longitudinal welded pipe. The method comprises the following steps: defining key parameters of trimming treatment, carrying out pre-welding trimming treatment on a welded edge of a pipe blank, and establishing a corresponding relationship between each parameter and temperature difference distribution in the wall thickness direction of a weld joint through software finite element analogue simulation, so as to realize control on each parameter of trimming treatment. Compared with the prior art, the invention has the advantages that main parameters for controlling the shape of the welding edge are defined, the influence of all the parameters on the temperature difference is explored, the induced current generation environment is improved, the temperature difference value of the highest temperature and the lowest temperature in the wall thickness direction of the welding seam is reduced, more uniform temperature distribution is generated, and the welding quality of the welding seam is improved; by means of finite element software numerical simulation, a welding edge shape parameter control method is established, time and capital cost brought by a trial-and-error method in actual production is avoided, and therefore the control process cost is greatly reduced while the quality of the high-frequency longitudinal welded pipe is improved.

Description

technical field [0001] The invention belongs to the field of high-frequency welded pipe production, and in particular relates to a quality control method for high-frequency straight seam welded pipes. Background technique [0002] High-frequency straight seam welded pipe is a kind of pressure welding without flux filling. It mainly uses the skin effect and proximity effect of high-frequency current to rapidly increase the temperature on both sides of the weld to the weldable temperature. The weld zone is fused into one. Compared with seamless steel pipes, high-frequency straight seam welded pipes have the advantages of high production efficiency, good mechanical properties, and strong compression resistance. At present, they have been widely used in oil and gas transportation. The proportion of welded pipes in oil well pipes used in the United States, Japan and other developed countries has accounted for half, while that in my country is only one-tenth, and they are mostly ...

AI Technical Summary

Problems solved by technology

[0003] The high-frequency straight seam welded pipe mainly uses the skin effect of high-frequency current, resulting in the highest magnetic induction intensity of the induced magnetic field at the weld seam at the inner and outer edges, and the induced magnetic field generates an induced current, and the current generates heat, which eventually causes the weld seam to wait The temperature on the inner and outer edges of the welded side is too high, which causes a large temperature difference in temperature distribution, but the welded pipe produces a large residual stress at the weld, which greatly reduces the quality of the weld

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