Large-caliber ultra-thick-wall pipe cold rolling method

Abstract

The invention relates to the technical field of steel pipe rolling, in particular to a large-caliber ultra-thick-wall pipe cold rolling method. The method mainly comprises the following steps that a steel pipe is conveyed into a cold rolling machine to be rolled, and meanwhile steel pipe feeding is kept; and in the rolling process, the steel pipe is rotated while steel pipe feeding is kept, wall reduction and diameter reduction happen to the steel pipe under the joint action of an inner die and an outer die, and a rolled pipe is formed. The cold rolling method is adopted for preparing the ultra-thick-wall pipe, the one-pass forming rolling technology is achieved, and rolling of continuous multiple passes is avoided. The quality of the ultra-thick-wall pipe prepared through the method is higher than that of ultra-thick-wall pipes prepared through a cold drawing method on the market, for example, the inner wall is smoother, and burrs are avoided.

Description

Technical field: [0001] The invention relates to the technical field of steel pipe rolling, in particular to a cold rolling method for large-diameter super-thick-wall pipes. Background technique: [0002] Thick-walled pipes, steel pipes with a ratio of outer diameter to wall thickness of less than 20 are called thick-walled pipes; steel pipes with a ratio of outer diameter to wall thickness of less than 5 are usually called ultra-thick-walled pipes. The outer diameter of the usual large-diameter thick-walled pipe reaches more than 400mm; while the outer diameter of the small-diameter ultra-thick-walled pipe is generally about 16mm, and the wall thickness is about 5mm. This type of pipe is widely used in high-pressure chemical equipment, aerospace fields, etc. [0003] In the prior art, such pipes are mainly cold drawn. Since the cold drawing process is a kind of stretching method, it is formed by drawing the steel pipe from a mouth with a limited shape of the inner and out...

AI Technical Summary

Problems solved by technology

Since the cold drawing process is a kind of stretching method, it is formed by drawing the steel pipe from a mouth with a limited shape of the inner and outer molds, so various problems such as inner wall burrs and inner wall roughness are prone to occur, and the drawing process Among them, the metal fluidity of the pipe wall is also difficult to control, and the problem of uneven wall thickness is prone to occur.

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