A Friction Stir Welding Mechanism for Circumferential Welds of Pipeline Steel

Abstract

The invention provides an annular weld joint type agitating frictional welding mechanism for pipeline steel. The mechanism is that a main clamping supporting seat and a secondary clamping supporting seat which have the opening and closing functions are used for clamping and positioning the pipeline steel; an agitating frictional welding machine is mounted on a chuck of the main clamping supporting seat through a welding machine mounting lifting plate and a rotating frame in a sequence, wherein the rotating frame is mounted on a circular annular track of the chuck of the main clamping supporting seat through a guide wheel above; a driving gear is rotated to engage with an outer gear ring of the chuck of the main clamping supporting seat to achieve rotating, and then the agitating frictional welding machine can circumferentially move around the pipeline steel; the welding machine mounting lifting plate is used for lifting by engaging of a lifting driving rack above and the lifting driving gear on the rotating frame; a lifting guide rail and a lifting guide sliding block are used for guiding the welding machine mounting lifting plate to lift together, and therefore, the welding height of the agitating frictional welding machine can be adjusted. Compared with the traditional fusion welding manner, the mechanism has the advantages that the welding efficiency of the pipeline steel can be increased; the heat input quantity is small, so that the coarsening of crystal particles in a heat influence area of a weld joint can be avoided being influenced, and as a result, the welding joint performance can be improved.

Description

technical field [0001] The invention belongs to the technical field of welding processing of pipeline steel, and in particular relates to a friction stir welding mechanism for annular weld seam of pipeline steel. Background technique [0002] At this stage, oil and gas pipeline transportation, as one of the important transportation methods of oil and natural gas, has irreplaceable advantages, and also has high transportation economy and efficiency. Compared with traditional oil tankers and natural gas carriers, it is almost unaffected Influence of climatic conditions. The core carrier of oil and gas pipelines is pipeline steel. With the continuous development of the economy, people's requirements for oil and gas transportation are also increasing. Oil and gas pipelines under construction are generally laid with large-diameter pipeline steel, and at the same time, they must meet the requirements of high-pressure transmission, which puts forward higher requirements for the pe...

AI Technical Summary

Problems solved by technology

[0003] So far, whether it is the pipe-making stage of pipeline steel or the laying stage of oil and gas pipelines, the welding of pipeline steel has adopted the traditional fusion welding method, and the traditional fusion welding method has a high heat input, which is inevitable It has caused serious coarsening and embrittlement of the metal in the weld seam and near the seam area, accompanied by defects such as cracks, pores, and segregation. With the increase in the strength of pipeline steel, the deterioration of the performance of welded joints is particularly serious

In addition, due to the grain boundary segregation caused by high heat input, it is also easy to seriously reduce the corrosion resistance of welded joints. Secondary preheating and slow cooling will seriously reduce the laying efficiency of oil and gas pipelines, and become one of the important factors restricting the construction of oil and gas pipelines

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