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.

Date of Patent:
Jun. 21, 2022

Filed:

Nov. 25, 2019
Applicant:

Kobe Steel, Ltd., Kobe, JP;

Inventors:

Tatsuya Asai, Kakogawa, JP;

Naoki Mizuta, Kakogawa, JP;

Hiroyuki Omori, Kakogawa, JP;

Takeshi Kojima, Kakogawa, JP;

Assignee:

Kobe Steel, Ltd., Kobe, JP;

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C22C 38/14 (2006.01); C23C 8/10 (2006.01); C22C 38/06 (2006.01); C22C 38/04 (2006.01); C22C 38/02 (2006.01); C22C 38/00 (2006.01); C21D 8/02 (2006.01); B21D 22/02 (2006.01); C21D 1/18 (2006.01); C21D 9/46 (2006.01); C21D 1/673 (2006.01); C22C 38/38 (2006.01); B21D 22/20 (2006.01);
U.S. Cl.
CPC ...
C22C 38/14 (2013.01); B21D 22/022 (2013.01); C21D 1/18 (2013.01); C21D 1/673 (2013.01); C21D 8/0205 (2013.01); C21D 8/0221 (2013.01); C21D 9/46 (2013.01); C22C 38/001 (2013.01); C22C 38/002 (2013.01); C22C 38/02 (2013.01); C22C 38/04 (2013.01); C22C 38/06 (2013.01); C22C 38/38 (2013.01); C23C 8/10 (2013.01); B21D 22/208 (2013.01); Y02P 10/20 (2015.11);
Abstract

Provided is a method for manufacturing a steel member through hot press forming using a steel sheet that contains a comparatively large amount of Si. The steel sheet includes, in mass ratio, C: 0.15% to 0.35%, Si: 1.0% to 3.0%, Mn: 1.0% to 3.0%, Al: more than 0% up to 0.10%, Ti: ([N]×48/14)% to 0.10% (where [N] denotes the amount of N in the steel sheet), B: 5 ppm to 50 ppm, P: more than 0% to less than 0.015%, S: more than 0% up to 0.010%, and N: more than 0% up to 0.010%, the balance being iron and unavoidable impurities. The average oxygen concentration from an outermost surface of the steel sheet down to a depth of 10 μm in a sheet thickness direction is 0.70 mass % or higher.


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