Method for regenerating a plug for use in a piercing machine

Patent metadata

Field	Value
Publication number	US-9764366-B2
Application number	US-201314391053-A
Country	US
Kind code	B2
Filing date	Mar 4, 2013
Priority date	Apr 11, 2012
Publication date	Sep 19, 2017
Grant date	Sep 19, 2017

Abstract

It is an objective to provide a plug capable of enhancing a usage count of the plug, which is for use in a piercing machine for piercing-rolling a billet, and a regenerating method of the plug. The plug ( 10 ) is for use in a piercing machine ( 30 ) for piercing-rolling a billet ( 36 ). The plug ( 10 ) includes a body ( 18 ), a columnar portion ( 20 ), and a sprayed film ( 16 ). The body ( 18 ) has a maximum diameter at its rear end. The columnar portion ( 20 ) has the same diameter as the diameter of the rear end of the body ( 18 ), and extends from the rear end of the body ( 18 ). The sprayed film ( 16 ) is formed on a surface of the body ( 18 ) and on a surface of the columnar portion ( 20 ).

First claim

The invention claimed is:

1. A regenerating method of a plug for use in a piercing machine for piercing-rolling a billet,
the plug including:
a body having a maximum diameter at a rear end of the body;
a columnar portion having the same diameter as a diameter of the rear end of the body, the columnar portion extending from the rear end of the body; and
a sprayed film formed on a surface of the body, and on a surface of the columnar portion, and
the regenerating method comprising:
a preparing step of preparing the plug used in the piercing-rolling,
a cutting step of cutting the plug so as to remove the sprayed film, and shifting the rear end of the body more rearward compared to the plug before the cutting step, and reducing the axial direction length of the columnar portion to restore an original shape and size of the body; and
a forming step of newly forming the sprayed film on the surface of the body, and on the surface of the columnar portion after the cutting step.

2. The regenerating method according to claim 1 , wherein
an entire surface of the body is covered with the sprayed film, and
in the forming step, the sprayed film is newly formed on the entire surface of the body, and on the surface of the columnar portion.

3. The regenerating method according to claim 2 , further comprising a step of applying a shotblast on the entire surface of the body, and on the surface of the columnar portion before the forming step and after the cutting step.

4. The regenerating method according to claim 1 , wherein
the plug further includes a build-up layer formed on the surface of the body,
the sprayed film is formed on the surface of the body in a region more rearward than the build-up layer, and on the surface of the columnar portion, and
in the forming step, the sprayed film is newly formed on the surface of the body in the region more rearward than the build-up layer, and on the surface of the columnar portion.

5. The regenerating method according to claim 4 , further comprising a step of applying a shotblast in the region on the surface of the body more rearward than the build-up layer, and on the surface of the columnar portion before the forming step and after the cutting step.

Assignees

• Nippon Steel & Sumitomo Metal Corp

Inventors

• Higashida Yasuto
• Hidaka Yasuyoshi
• Shimoda Kazuhiro
• Tatebayashi Yosuke

Classifications

• B21B19/04 Primary

  Rolling basic material of solid, i.e. non-hollow, structure; Piercing {, e.g. rotary piercing mills} · CPC title

• B05D3/12

  by mechanical means · CPC title

• B05D1/02

  performed by spraying · CPC title

• B21B28/00 Primary

  Maintaining rolls or rolling equipment in effective condition (lubricating, cooling or heating rolls while in use B21B27/06) · CPC title

• B21B25/00

  Mandrels for metal tube rolling mills, e.g. mandrels of the types used in the methods covered by group B21B17/00; Accessories or auxiliary means therefor {; Construction of, or alloys for, mandrels or plugs} · CPC title