Plug for large-hole series medium- and thick-wall capillaries

Abstract

The invention relates to the field of steel pipe production, in particular to a plug for punching of large-hole series medium- and thick-wall capillaries. The outline of the plug consists of a punching section, an expanding section, a rolling section, a circling section and a reverse cone section. The front end surface of the plug adopts a flat head design, and a bar inserting hole is formed on the tail end of the plug; connection between the front end surface of the plug and the punching section is realized through arc transition, wherein the arc radius is R2, and the arc radius of the outline of the punching section is R3; the expanding section and the rolling section are cones, wherein the taper of the expanding section is a2, and the taper of the rolling section is a1; the outline of the reverse cone section is an arc of which the arc radius is R1; and the circling section is a cylinder.

Description

technical field [0001] The invention relates to the field of steel pipe production, in particular to a plug used for piercing thick-walled capillaries in a series of large holes. Background technique [0002] At present, the 340 unit hot rolling production line that produces hot-rolled seamless steel pipes adopts the production process of conical roll perforation + 5 racks continuous rolling tube + 3 racks for tube removal + 12 racks for sizing, and the tube billet is perforated by tapered rolls machine, which can be used to thread capillary tubes made of high alloy steel and thinner tube walls. [0003] The plug is an important internal deformation tool in the piercing process, which plays an important role in the quality and wall thickness of the capillary inner surface. The plug used for piercing on the cone roll piercing machine is attached figure 1 As shown, the outer profile of the plug is composed of a perforation section 1, a diameter-expanding section 2, a diamete...

AI Technical Summary

Problems solved by technology

[0006] (3) The wall thickness at the end of the steel pipe seriously exceeds the standard, resulting in severe cutting of the head and tail of the steel pipe, and a high return cutting rate

[0007] Due to the above problems, it is easy to cause irregular, curved, and large ellipticity of the thick-walled capillary tube in the large-hole type series, which is not conducive to inserting the rod, which affects the control of the quality of the inner surface of the steel pipe, and cannot meet the high-precision requirements of the finished pipe for wall thickness.

[0008] A big reason for the above problems is due to the instability of the piercing process, and the key to the instability of the piercing process is that the original design of the plug has completely failed to meet the requirements for the production of thick-walled capillary tubes in the series of large holes.

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