Large-diameter thin-wall seamless tube rotation extrusion forming method

Abstract

The invention provides a large-diameter thin-wall seamless tube rotation extrusion forming method. A tubular product blank with D0 and d0 as the external diameter and the internal diameter generates rotational motion with an angular velocity of omega and axial motion with a leftward speed upsilon under the action of a core rod and is sequentially subjected to extrusion deformation of an extrusion wheel and correction deformation of a shape correction wheel to obtain a high-precision tubular product with D and d as the external diameter and the internal diameter, wherein a circular passage is formed in the center of the extrusion wheel; the extrusion wheel is mounted on a right permanent seat through an extrusion wheel thrust bearing and an extrusion wheel antifriction bearing; the extrusion wheel thrust bearing bears axial thrust when the tubular product deforms; the extrusion wheel antifriction bearing ensures that the extrusion wheel can be driven to rotate when the tubular product forms; the shape correction wheel is mounted on a left permanent seat through a shape correction wheel thrust bearing and a shape correction wheel antifriction bearing; the shape correction wheel thrust bearing bears axial thrust when the tubular product deforms; and the shape correction wheel antifriction bearing ensures that the shape correction wheel can be driven to rotate when the tubular product forms. The large-diameter thin-wall seamless tube rotation extrusion forming method inherits the advantages of the three-dimensional pressure stress state forming of the extrusion process.

Description

technical field [0001] The invention relates to the technical field of seamless pipe manufacturing, in particular to a labor-saving extrusion forming of a large-diameter thin-wall seamless pipe and a subsequent finishing method of the seamless pipe. Background technique [0002] At present, the finishing of seamless steel pipes, stainless steel pipes and copper pipes generally adopts the cold rolling process, that is, the thick-walled pipes with rough surfaces are processed into thin-walled pipes with smooth surfaces. The commonly used cold-rolling process for seamless pipes is basically based on the invention patent of "Rockright Mill". It is quite difficult to cold-roll large-diameter and thin-walled seamless pipes using this process. [0003] With the rapid development of aerospace, energy chemical industry, and ship transportation, the demand for high-precision large-diameter thin-walled pipes is becoming more and more urgent. For example, more than 90% of my country's n...

AI Technical Summary

Problems solved by technology

The investment cost of the large-scale Rocklet cold-rolling mill is huge, and the linear speed difference between the middle and the end of the concave roller table of the roll is large, which may easily cause cracking of the tube blank and large wall thickness difference; the production efficiency of the large-scale drawing machine is low and the plasticity of the material is Strict requirements, long cycle time and high cost; the material utilization rate and production efficiency of the internal boring and external turning method of hot-rolled thick-walled pipes are low, and the length of the cutter bar is too long and the rigidity is poor, resulting in the inability to guarantee the accuracy of the workpiece; the pipe length of the strong spinning method is short, The powerful spinning of thin-walled pipes with a diameter greater than 500mm and a length greater than 8m is currently in the stage of research in China

[0004] At present, the manufacturing process of high-end seamless pipes includes a large number of repeated cold rolling and cold drawing processes, and affected by the equipment itself, the diameter and quality of steel pipe products have great limitations

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