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The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Patent No.:

US 9194031 B1

PDFFull Text
Date of Patent:
Nov. 24, 2015

Filed:

Nov. 28, 2012

Tool for piercing mill

Applicant:

Jfe Steel Corporation, Chiyoda-ku, Tokyo, JP;

Inventors:

Kenji Ichino, Handa, JP;

Seiji Ozaki, Handa, JP;

Tetsuo Mochida, Handa, JP;

Assignee:

JFE STEEL CORPORATION, Tokyo, JP;

Attorney:

Holtz, Holtz, Goodman & Chick PC

Primary Examiner:

Deborah Yee

Int. Cl.
CPC ...
C22C 38/44 (2006.01); C22C 38/48 (2006.01); C22C 38/52 (2006.01); C21D 9/22 (2006.01); B21B 25/00 (2006.01); C21D 9/00 (2006.01); C22C 38/00 (2006.01); C22C 38/60 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/06 (2006.01); C21D 1/84 (2006.01); B21B 25/04 (2006.01);
U.S. Cl.
CPC ...
C22C 38/52 (2013.01); B21B 25/00 (2013.01); C21D 1/84 (2013.01); C21D 9/00 (2013.01); C21D 9/22 (2013.01); C22C 38/00 (2013.01); C22C 38/002 (2013.01); C22C 38/02 (2013.01); C22C 38/04 (2013.01); C22C 38/06 (2013.01); C22C 38/44 (2013.01); C22C 38/48 (2013.01); C22C 38/60 (2013.01); B21B 25/04 (2013.01); C21D 2211/005 (2013.01);
Abstract

A tool for a piercing mill, the tool comprising a scale layer in a surface layer of a substrate steel, wherein the scale layer includes a net structure scale layer that is formed on a substrate steel side, has a thickness of 10 to 200 μm in a depth direction, and is complicatedly intertwined with a metal; and wherein a microstructure on the substrate steel side in a range of at least 300 μm in the depth direction from an interface between the net structure scale layer and the substrate steel contains a ferrite phase at an area fraction of 50% or more, the ferrite phase containing 400/mmor more ferrite grains having a maximum length of 1 to 60 μm.

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