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 12221701 B1

PDFFull Text
Date of Patent:
Feb. 11, 2025

Filed:

Mar. 29, 2024

Welded member of galvanized steel sheets

Applicant:

Posco Co., Ltd, Pohang-si, KR;

Inventors:

Ki-Cheol Kang, Gwangyang-si, KR;

Sang-Ho Uhm, Incheon, KR;

Chang-Woon Jee, Gwangyang-si, KR;

Yeon-Chae Jeong, Gwangyang-si, KR;

Kwang-Tai Min, Gwangyang-si, KR;

Assignee:

POSCO CO., LTD, Pohang-si, KR;

Attorney:

CANTOR COLBURN LLP

Primary Examiner:

Katherine A Christy

Int. Cl.
CPC ...
C23C 2/06 (2006.01); C21D 8/02 (2006.01); C21D 9/46 (2006.01); C22C 38/00 (2006.01); C22C 38/02 (2006.01); C22C 38/06 (2006.01); C22C 38/22 (2006.01); C22C 38/24 (2006.01); C22C 38/26 (2006.01); C22C 38/32 (2006.01); C22C 38/38 (2006.01); C23C 2/02 (2006.01); C23C 2/28 (2006.01); C23C 2/40 (2006.01);
U.S. Cl.
CPC ...
C23C 2/06 (2013.01); C21D 8/0205 (2013.01); C21D 8/0226 (2013.01); C21D 8/0236 (2013.01); C21D 9/46 (2013.01); C22C 38/001 (2013.01); C22C 38/002 (2013.01); C22C 38/008 (2013.01); C22C 38/02 (2013.01); C22C 38/06 (2013.01); C22C 38/22 (2013.01); C22C 38/24 (2013.01); C22C 38/26 (2013.01); C22C 38/32 (2013.01); C22C 38/38 (2013.01); C23C 2/02 (2013.01); C23C 2/0222 (2022.08); C23C 2/0224 (2022.08); C23C 2/024 (2022.08); C23C 2/28 (2013.01); C23C 2/40 (2013.01);
Abstract

A welded member includes: a first steel sheet including a base steel sheet and a zinc-based plating layer formed on a surface of the base steel sheet; and a second steel sheet spot-welded on the first steel sheet and facing the zinc-based plating layer of the first steel sheet, a spot-welded zone being formed between the first steel sheet and the second steel sheet. A surface layer of the base steel sheet has a decarburization ratio of 30% or more. The decarburization ratio is represented by equation: Decarburization ratio (%) of surface layer=(1−average carbon concentration in surface layer/bulk carbon concentration)*100 where the surface layer refers to a region of the base steel sheet from the surface thereof to a depth of 35 μm. A shoulder portion of the spot-welded zone includes a B-type crack having a length of 100 μm or less, and no C-type crack.

Find Patent Forward Citations

Loading…