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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 9429255 B1

PDFFull Text
Date of Patent:
Aug. 30, 2016

Filed:

Apr. 02, 2013

Hollow seamless pipe for high-strength spring

Applicants:

Kobe Steel, Ltd., Kobe-shi, JP;

Shinko Metal Products Co., Ltd., Kitakyushu-shi, JP;

Nhk Spring Co., Ltd., Yokohama-shi, JP;

Inventors:

Takuya Kochi, Hyogo, JP;

Hitoshi Hatano, Hyogo, JP;

Eiichi Tamura, Hyogo, JP;

Kotaro Toyotake, Fukuoka, JP;

Takashi Yajima, Kanagawa, JP;

Akira Tange, Kanagawa, JP;

Assignees:

KOBE STEEL, LTD., Kobe-shi, JP;

SHINKO METAL PRODUCTS CO., LTD., Kitakyushu-shi, JP;

NHK SPRING CO., LTD., Yokohama-shi, JP;

Attorney:

Oblon, McClelland, Maier & Neustadt, L.L.P

Primary Examiner:

Daniel J Schleis

Int. Cl.
CPC ...
B22D 19/00 (2006.01); F16L 9/02 (2006.01); C21D 8/10 (2006.01); C21D 9/02 (2006.01); C21D 9/08 (2006.01); C22C 38/00 (2006.01); C22C 38/04 (2006.01); C22C 38/06 (2006.01); C22C 38/20 (2006.01); C22C 38/24 (2006.01); C22C 38/28 (2006.01); C22C 38/34 (2006.01); C22C 38/42 (2006.01); C22C 38/46 (2006.01); C22C 38/50 (2006.01); C21D 6/00 (2006.01); C22C 38/02 (2006.01); C22C 38/44 (2006.01); C22C 38/48 (2006.01); C22C 38/54 (2006.01); F16F 1/02 (2006.01);
U.S. Cl.
CPC ...
F16L 9/02 (2013.01); C21D 6/008 (2013.01); C21D 8/10 (2013.01); C21D 9/02 (2013.01); C21D 9/08 (2013.01); C22C 38/001 (2013.01); C22C 38/002 (2013.01); C22C 38/005 (2013.01); C22C 38/02 (2013.01); C22C 38/04 (2013.01); C22C 38/06 (2013.01); C22C 38/20 (2013.01); C22C 38/24 (2013.01); C22C 38/28 (2013.01); C22C 38/34 (2013.01); C22C 38/42 (2013.01); C22C 38/44 (2013.01); C22C 38/46 (2013.01); C22C 38/48 (2013.01); C22C 38/50 (2013.01); C22C 38/54 (2013.01); F16F 1/021 (2013.01); C21D 2211/004 (2013.01);
Abstract

A hollow seamless pipe for a high-strength spring in the present invention includes a steel material in which chemical component compositions are properly adjusted, wherein a depth of a whole decarburized layer in an inner surface layer part is 100 μm or less, a depth of a flaw which is present in an inner surface is 40 μm or less, a width of the flaw is 60 μm or less, and a number density of a carbide which has a circle equivalent diameter of 500 nm or more and is present in the inner surface layer part is 1.8×10particles/μmor less.

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