Penetration extrusion process of seamless pipe and hollow cast ingot

Abstract

The invention discloses a hollow cast ingot, the hollow cast ingot is used for extruding and forming a seamless pipe through perforation. The hollow cast ingot comprises a cast ingot body, a stepped through hole is formed in the cast ingot body in the extrusion direction, and the through hole comprises a limiting hole and a vent hole which are connected in an end to end mode; the invention furtherdiscloses a perforation extrusion process of the seamless pipe, the perforation extrusion process comprises the following steps that S1, the hollow cast ingot is adopted, the hollow cast ingot is placed in extrusion equipment; S2, an air hole part at the front end of a extruding needle is firstly penetrated out by the extruding needle to form a front end inner diameter small part; S3, the rest metal is extruded by an extrusion shaft to form a product part which is consistent with the shape of a seamless pipe to be formed; and S4, the front end inner diameter small part is cut out, and the rest rear product is a product which is consistent with the shape of the seamless pipe to be formed. By applying the hollow cast ingot and the perforation extrusion process, the vent hole part is extruded out of an extrusion die to keep exhausting gas when the perforation is carried out, so that the product is prevented from generating a collapsing cavity, inner surface defects and pollutants are brought out, so that it is guaranteed that the product has good inner surface quality.

Description

technical field [0001] The invention relates to the technical field of extrusion, more specifically, to a perforating extrusion process for seamless pipes, and also to a hollow ingot for perforating and extruding seamless pipes. Background technique [0002] There are two production methods for existing seamless pipes and hollow profiles, one is hollow ingot extrusion, and the other is solid ingot perforation extrusion. Due to the poor quality of the inner cavity of the hollow ingot, defects or pollutants will be brought into the inner surface of the product. The perforation of the solid ingot will greatly improve the quality of the inner surface, but because a part of the metal pierced out will block the head end of the product, the inner cavity of the product will be in a vacuum state. When using a solid ingot for piercing and extrusion, it is necessary to punch holes in time after the head end of the product is extruded from the mold to prevent the product from collapsin...

AI Technical Summary

Problems solved by technology

[0005] In view of this, the first object of the present invention is to provide a hollow ingot whose structural design can effectively solve the problem of poor inner surface quality or the use of The problem of large limitations in piercing and extrusion of solid ingots, the second purpose of the present invention is to provide a piercing and extrusion process for seamless pipes

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