logo

For the Inventor, By the Inventor

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 10131965 B1

PDFFull Text
Date of Patent:
Nov. 20, 2018

Filed:

Nov. 18, 2014

Steel bar

Applicant:

Nippon Steel & Sumitomo Metal Corporation, Tokyo, JP;

Inventors:

Atsushi Monden, Hokkaido, JP;

Shunta Homma, Narashino, JP;

Koichi Banno, Hokkaido, JP;

Assignee:

NIPPON STEEL & SUMITOMO METAL CORPORATION, Tokyo, JP;

Attorney:

Birch, Stewart, Kolasch & Birch, LLP

Primary Examiner:

Keith Walker

Assistant Examiner:

John A Hevey

Int. Cl.
CPC ...
C21D 9/52 (2006.01); C21D 8/06 (2006.01); C22C 38/00 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/06 (2006.01); C22C 38/08 (2006.01); C22C 38/12 (2006.01); C22C 38/14 (2006.01); C22C 38/16 (2006.01); C22C 38/18 (2006.01); C22C 38/22 (2006.01); C21D 1/06 (2006.01); C21D 3/04 (2006.01); C22C 38/60 (2006.01);
U.S. Cl.
CPC ...
C21D 9/525 (2013.01); C21D 1/06 (2013.01); C21D 3/04 (2013.01); C21D 8/06 (2013.01); C21D 8/065 (2013.01); C22C 38/00 (2013.01); C22C 38/001 (2013.01); C22C 38/002 (2013.01); C22C 38/005 (2013.01); C22C 38/008 (2013.01); C22C 38/02 (2013.01); C22C 38/04 (2013.01); C22C 38/06 (2013.01); C22C 38/08 (2013.01); C22C 38/12 (2013.01); C22C 38/14 (2013.01); C22C 38/16 (2013.01); C22C 38/18 (2013.01); C22C 38/22 (2013.01); C22C 38/60 (2013.01); C21D 9/52 (2013.01); C21D 2211/002 (2013.01); C21D 2211/005 (2013.01); C21D 2211/008 (2013.01);
Abstract

A steel bar according to one embodiment of the present invention includes predetermined chemical composition, wherein a quenching deflection in a cross section is 1.5 mm or less, wherein Δmax and Δmin is 1.5 mm or less, wherein a structure in a surface layer area includes 10 area % or less of ferrite and a remainder including one or more selected from a group consisting of a bainite and a martensite, wherein an average value of the grain size of a bcc phase in the surface layer area is 1.0 to 10.0 μm, wherein an average value of the grain size of the bcc phase in a center area is 1.0 to 15.0 μm, wherein a hardness of a region of which a depth from the surface is 50 μm is Hv200 to Hv500, and wherein a total decarburized layer thickness DM-T is 0.20 mm or less.

Find Patent Forward Citations

Loading…