Method for producing ultra thin wall metallic tube with cold working process

Abstract

An exemplary embodiment of the invention provides a method for producing an ultra thin wall metallic tube by cold working method with significant wall thickness reduction. In a method for producing the metallic tube with a cold pilger mill according to the invention, cold rolling is performed while tube diameters are being expanded using rolls having tapered groove dies whose calibers increase from an engaging entry side toward a finishing exit side. In a method for producing the metallic tube with a drawing machine according to the invention, cold drawing is performed while the tube diameters are being expanded using a solid die whose calibers increase from an engaging entry side toward a finishing exit side and a plug of a tapered mandrel bar whose diameters increase from an entry side of the die toward an exit side. In the metallic tube producing method, a maximum diameter of the plug or tapered mandrel bar may be larger than an outside diameter of the mother tube.

Description

[0001] This application is a divisional application of an invention patent application with an application date of May 24, 2006, an application number of 200680018686.0, and an invention title of a method for manufacturing ultra-thin-walled metal pipes by cold working. technical field [0002] The present invention relates to a cold working method of a metal pipe, and in particular provides a method for manufacturing an ultra-thin metal pipe by a cold working method which greatly expands the manufacturable range of the thin wall of the metal pipe. Background technique [0003] When the metal pipe cannot meet the quality, strength or dimensional accuracy requirements in the hot-worked state, it must be sent to the cold working process. As the cold working process, there are usually a cold drawing method using a die and a plug, or a die and a mandrel, and a cold rolling method using a pilger cold rolling mill. [0004] In the cold rolling method using a pilger cold rolling mil...

AI Technical Summary

Problems solved by technology

Of course, the thinner the wall thickness of the tube, the greater the tensile stress in the length direction, and the easier it is for the tube to break. Therefore, the wall thickness reduction rate is naturally limited.

Therefore, the drawing with a large wall thickness reduction rate needs to increase the number of times of drawing and repeat the drawing operation, and each drawing needs to be lubricated, resulting in high cost

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