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 10351927 B1

Date of Patent:

Jul. 16, 2019

Filed:

Dec. 24, 2014

Hot-rolled steel sheet for high strength galvanized steel sheet, having excellent surface quality, and method for producing same

Applicant:

Posco, Pohang-si, Gyeongsangbuk-do, KR;

Inventors:

Hyo Jung Kwak, Gwangyang-si, KR;

Young-Ha Kim, Gwangyang-si, KR;

Seok Jong Seo, Jeonju-si, KR;

Assignee:

POSCO, Pohang-si, Gyeongsanbuk-do, KR;

Attorney:

Morgan Lewis & Bockius LLP

Primary Examiner:

Michael E La Villa

Int. Cl.

CPC ...

C21D 9/46 (2006.01); C21D 8/02 (2006.01); C23C 2/06 (2006.01); C22C 38/14 (2006.01); C22C 38/02 (2006.01); C22C 38/06 (2006.01); C22C 38/04 (2006.01); C22C 38/00 (2006.01); C22C 38/12 (2006.01); C23F 17/00 (2006.01); B32B 15/01 (2006.01); C22C 38/26 (2006.01); C22C 38/42 (2006.01); C22C 38/40 (2006.01); C22C 38/18 (2006.01); C22C 38/08 (2006.01); C22C 38/16 (2006.01); C22C 38/24 (2006.01); C22C 38/28 (2006.01); C22C 38/22 (2006.01); C22C 38/20 (2006.01); C22C 38/48 (2006.01); C23C 28/02 (2006.01); C22C 38/46 (2006.01); C23C 28/00 (2006.01); C22C 38/50 (2006.01); C23C 30/00 (2006.01); C22C 38/44 (2006.01); B32B 15/18 (2006.01); B32B 15/04 (2006.01); C23C 2/02 (2006.01); C23C 2/40 (2006.01);

U.S. Cl.

CPC ...

C21D 9/46 (2013.01); B32B 15/013 (2013.01); B32B 15/04 (2013.01); B32B 15/043 (2013.01); B32B 15/18 (2013.01); C21D 8/02 (2013.01); C21D 8/0205 (2013.01); C21D 8/0226 (2013.01); C21D 8/0278 (2013.01); C22C 38/002 (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 38/20 (2013.01); C22C 38/22 (2013.01); C22C 38/24 (2013.01); C22C 38/26 (2013.01); C22C 38/28 (2013.01); C22C 38/40 (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); C23C 2/02 (2013.01); C23C 2/06 (2013.01); C23C 2/40 (2013.01); C23C 28/023 (2013.01); C23C 28/025 (2013.01); C23C 28/3225 (2013.01); C23C 30/00 (2013.01); C23C 30/005 (2013.01); C23F 17/00 (2013.01); C21D 2211/002 (2013.01); C21D 2211/004 (2013.01); C21D 2211/005 (2013.01); C21D 2211/009 (2013.01); Y10T 428/1266 (2015.01); Y10T 428/12611 (2015.01); Y10T 428/12618 (2015.01); Y10T 428/12667 (2015.01); Y10T 428/12799 (2015.01); Y10T 428/12951 (2015.01); Y10T 428/12958 (2015.01); Y10T 428/12972 (2015.01); Y10T 428/12993 (2015.01); Y10T 428/2495 (2015.01); Y10T 428/24967 (2015.01); Y10T 428/263 (2015.01); Y10T 428/264 (2015.01); Y10T 428/265 (2015.01);

Abstract

The present invention relates to a hot-rolled steel sheet for a high strength galvanized steel sheet, having excellent surface quality, and a method for producing the same, the hot-rolled steel sheet comprising, by weight %: C: 0.05 to 0.15%, Si: 0.03 to 0.10%, Mn: 0.7 to 1.39%, P: 0.001 to 0.05%, S: 0.001 to 0.03%, Al: 0.002 to 0.035%, and the remainder being Fe and unavoidable impurities. The weight ratio of Mn/Si is 15 to 25, the weight ratio of C/Si is 1 to 5, and the weight ratio of Si/P is 3 to 10. The hot-rolled steel sheet has a microstructure consisting of, in area fraction, 10 to 40% of bainite, 20 to 30% of pearlite and 40 to 60% of ferrite, and includes a ternary eutectic compound of FeO, FeSiOand Fe(PO)formed within 50 μm from the surface.

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