公开(公告)号：US20240401166A1

公开(公告)日：2024-12-05

申请号：US18799527

申请日：2024-08-09

Applicant: POSCO CO., LTD ,  POSTECH ACADEMY-INDUSTRY FOUNDATION

Inventor： Sea-Woong LEE ,  Bruno C. DE COOMAN ,  Kyoo-Young LEE ,  Eun-Jung SEO ,  Seon-Jong LEE ,  Joo-Hyun RYU ,  Won-Hwi LEE

IPC: C21D9/46 ,  C21D6/00 ,  C21D8/02 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/38 ,  C23C2/02 ,  C23C2/06 ,  C23C2/28 ,  C23C2/40

Abstract: One aspect of the present invention relates to an ultrahigh-strength steel sheet having an excellent yield ratio, comprising, by wt %, 0.3-0.5% of C, 2.0% (excluding 0%) of Si, 3.0-6.5% of Mn, 0.02% or less of P, 0.01% or less of S, 0.01-3.0% of Al, 0.02% or less (excluding 0%) of N, and the balance of Fe and other inevitable impurities, and a microstructure comprises 5-30% of remaining austenite by area fraction and comprises 5% or less of secondary martensite.

公开(公告)号：US20190119770A1

公开(公告)日：2019-04-25

申请号：US16094323

申请日：2017-04-20

Applicant: POSCO ,  POSTECH ACADEMY-INDUSTRY FOUNDATION

Inventor： Joo-Hyun RYU ,  Nack-Joon KIM ,  Sung-Hak LEE ,  Won-Hwi LEE ,  Kyoo-Young LEE ,  Sea-Woong LEE

IPC: C21D8/02 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/00 ,  C22C38/12 ,  C22C38/14 ,  C23C2/28 ,  C23C2/06 ,  C23C2/02 ,  C23C2/40 ,  C21D9/46

Abstract: Provided is an ultrahigh-strength steel sheet for a vehicle and, more specifically, to an ultrahigh-strength and high-ductility steel sheet having excellent yield ratio and a manufacturing method therefor. Provided is an ultrahigh-strength and high-ductility steel sheet for cold press forming and a manufacturing method therefor, the steel sheet ensuring ultrahigh strength and high ductility since an alloy component of steel and manufacturing conditions are controlled and, simultaneously, having excellent impact characteristics due to a high yield strength ratio (yield ratio). Provided is the steel sheet capable of satisfying formability and impact stability, which are required for a vehicle steel sheet for cold forming, and replacing a conventional steel sheet for hot press forming, thereby reducing manufacturing costs.

公开(公告)号：US20190256940A1

公开(公告)日：2019-08-22

申请号：US16347704

申请日：2017-11-07

Applicant: POSCO ,  POSTECH ACADEMY-INDUSTRY FOUNDATION

Inventor： Sea-Woong LEE ,  Bruno C. DE COOMAN ,  Kyoo-Young LEE ,  Eun-Jung SEO ,  Seon-Jong LEE ,  Joo-Hyun RYU ,  Won-Hwi LEE

IPC: C21D9/46 ,  C21D8/02 ,  C21D6/00 ,  C23C2/02 ,  C23C2/06 ,  C23C2/40 ,  C22C38/38 ,  C22C38/12 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00

Abstract: One aspect of the present invention relates to an ultrahigh-strength steel sheet having an excellent yield ratio, comprising, by wt %, 0.3-0.5% of C, 2.0% (excluding 0%) of Si, 3.0-6.5% of Mn, 0.02% or less of P, 0.01% or less of S, 0.01-3.0% of Al, 0.02% or less (excluding 0%) of N, and the balance of Fe and other inevitable impurities, and a microstructure comprises 5-30% of remaining austenite by area fraction and comprises 5% or less of secondary martensite.

公开(公告)号：US20220056564A1

公开(公告)日：2022-02-24

申请号：US17415543

申请日：2019-12-18

Applicant: POSCO

Inventor： Ki-Cheol KANG ,  Sea-Woong LEE ,  Kyoo-Young LEE ,  Jong-Ho KIM ,  Young-Roc IM

IPC: C22C38/38 ,  C22C38/32 ,  C22C38/26 ,  C22C38/28 ,  C22C38/02 ,  C22C38/06 ,  C22C38/00 ,  C22C38/22 ,  C21D9/46 ,  C21D8/02 ,  C23C2/06 ,  C23C2/40

Abstract: Provided is a zinc plated steel sheet having excellent spot weldability and a manufacturing method thereof. The zinc plated steel sheet includes a steel sheet and a zinc plated layer formed on the surface of the steel sheet, wherein the ratio (a/b) between a widthwise average value (a) of thickness of an internal oxidized layer and a widthwise standard deviation (b) of thickness of the internal oxidized layer in the steel sheet may be 1.5 or more.

公开(公告)号：US20200248281A1

公开(公告)日：2020-08-06

申请号：US15769924

申请日：2016-10-05

Applicant: POSCO

Inventor： Kyoo-Young LEE ,  Joo-Hyun RYU ,  Sea-Woong LEE ,  Won-Hwi LEE ,  Byun-Mok HWANG

IPC: C21D9/46 ,  B32B15/01 ,  C22C38/14 ,  C22C38/12 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  C21D8/02 ,  C21D6/00 ,  C23C2/06 ,  C23C2/28 ,  C23C2/40

Abstract: Provided is an ultra-high strength steel plate for automobiles and, more specifically, to an ultra-high strength steel plate having high formability and hole expandability, and a method for manufacturing the ultra-high strength steel plate. The ultra-high strength steel plate includes: by wt %, carbon (C): 0.04% to 0.17%, silicon (Si): 2% or less, manganese (Mn): 4% to 10%, phosphorous (P): 0.05% or less (excluding 0%), sulfur (S): 0.02% or less (excluding 0%), aluminum (Al): 0.5% or less (excluding 0%), nitrogen (N): 0.02% or less (excluding 0%), and a balance of iron (Fe) and inevitable impurities. Carbon (C) and manganese (Mn) satisfy Formula C+(Mn/25)≤0.46. The ultra high strength steel plate has a microstructure comprising retained austenite in a volume fraction of 20% or greater and annealed martensite in a volume fraction of 50% or greater.

公开(公告)号：US20180023171A1

公开(公告)日：2018-01-25

申请号：US15720168

申请日：2017-09-29

Applicant: POSCO

Inventor： Jin-Keun OH ,  Kyoo-Young LEE ,  Yeol-Rae CHO ,  Eul-Yong CHOI ,  Ki-Soo KIM

IPC: C22C38/38 ,  B21B1/04 ,  C23C2/02 ,  C22C38/60 ,  C22C38/58 ,  C22C38/18 ,  C22C38/16 ,  C22C38/14 ,  C22C38/12 ,  C22C38/08 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  C23C2/06 ,  B21B15/00 ,  C21D6/00 ,  C21D8/02 ,  C21D8/04 ,  C21D9/46 ,  C23C2/12 ,  C21D7/13

CPC classification number: C22C38/38 ,  B21B1/04 ,  B21B15/00 ,  B21B2015/0057 ,  C21D6/005 ,  C21D7/13 ,  C21D8/02 ,  C21D8/0226 ,  C21D8/0463 ,  C21D8/0473 ,  C21D8/0478 ,  C21D9/46 ,  C21D2211/001 ,  C21D2211/002 ,  C21D2211/005 ,  C21D2211/008 ,  C22C38/001 ,  C22C38/002 ,  C22C38/008 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/18 ,  C22C38/58 ,  C22C38/60 ,  C23C2/02 ,  C23C2/06 ,  C23C2/12

Abstract: Provided is a warm-pressed member comprising, by weight %, C: 0.01% to 0.5%, Si: 3.0% or less (excluding 0%), Mn: 3% to 15%, P: 0.0001% to 0.1%, S: 0.0001% to 0.03%, Al: 3.0% or less (excluding 0%), N: 0.03% or less (excluding 0%), and the balance of Fe and inevitable impurities. After a warm press forming process and a cooling process, the warm-pressed member has a microstructure comprising: 5 volume % to 50 volume % of retained austenite; and at least one of ferrite, martensite, tempered martensite, and bainite as a remainder.

公开(公告)号：US20160355903A1

公开(公告)日：2016-12-08

申请号：US15103078

申请日：2014-12-23

Applicant: POSCO

Inventor： Jai-Hyun KWAK ,  Kyoo-Young LEE ,  Hang-Sik CHO ,  Joo-Hyun RYU ,  Man-Young PARK

IPC: C21D9/52 ,  C21D9/573 ,  C21D9/60 ,  C21D1/52 ,  C21D1/42 ,  C21D1/34 ,  C21D1/60 ,  C21D1/613 ,  C21D1/773 ,  C22C38/14 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  C21D9/56

CPC classification number: C21D9/52 ,  C21D1/26 ,  C21D1/34 ,  C21D1/40 ,  C21D1/42 ,  C21D1/52 ,  C21D1/60 ,  C21D1/613 ,  C21D1/773 ,  C21D9/56 ,  C21D9/561 ,  C21D9/573 ,  C21D9/60 ,  C21D2211/005 ,  C22C38/001 ,  C22C38/002 ,  C22C38/004 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/14 ,  Y02P10/253

Abstract: An apparatus for continuous annealing of a strip comprises: a first heating zone configured to firstly heat a strip; a first cooling or constant temperature maintaining zone configured to cool the strip firstly heated in the first heating zone or to maintain the strip at a constant temperature; a second heating and soaking zone configured to secondarily heat and soak the strip cooled or remaining at the constant temperature in the first cooling or constant temperature maintaining zone; and a second cooling zone configured to cool the strip heated and soaked in the second heating and soaking zone.

Abstract translation: 一种用于条带的连续退火的装置包括：第一加热区，被配置为首先加热条带; 第一冷却或恒温保持区域，其被配置为冷却在第一加热区域中首先加热的条带或将条带保持在恒定温度; 第二加热和均热区域，其被配置为二次加热和浸泡在第一冷却或恒温保持区域中被冷却或保持在恒定温度的条带; 以及第二冷却区，被配置为冷却在第二加热和均热区中加热和浸泡的条。

公开(公告)号：US20190276913A1

公开(公告)日：2019-09-12

申请号：US16426307

申请日：2019-05-30

Applicant: POSCO

Inventor： Jai-Hyun KWAK ,  Kyoo-Young LEE ,  Hang-Sik CHO ,  Joo-Hyun RYU ,  Man-Young PARK

IPC: C21D9/52 ,  C21D1/60 ,  C21D9/56 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C21D1/34 ,  C22C38/14 ,  C21D1/613 ,  C21D1/773 ,  C21D9/60 ,  C22C38/00 ,  C21D1/26 ,  C21D9/573 ,  C21D1/40 ,  C21D1/52 ,  C21D1/42

Abstract: Provided is a method of continuously annealing a strip. The method includes: firstly heating a strip in a first heating zone; firstly cooling the firstly heated strip or maintaining the firstly heated strip at a constant temperature in a first cooling or constant temperature maintaining zone; secondarily heating and soaking the strip, firstly cooled or remaining at the constant temperature, in a second heating and soaking zone; and secondarily cooling the strip, secondarily heated and soaked, in a second cooling zone.

公开(公告)号：US20190233910A1

公开(公告)日：2019-08-01

申请号：US16333778

申请日：2017-10-24

Applicant: POSCO

Inventor： Joo-Hyun RYU ,  Kyoo-Young LEE ,  Sea-Woong LEE ,  Won-Hwi LEE

IPC: C21D8/02 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/14 ,  C22C38/12 ,  C22C38/00

CPC classification number: C21D8/0247 ,  C21D6/005 ,  C21D8/0205 ,  C21D8/0226 ,  C21D8/0263 ,  C21D2211/001 ,  C21D2211/008 ,  C22C38/001 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/14 ,  C23C2/02 ,  C23C2/06 ,  C23C2/40

Abstract: Provided is an ultra-high-strength steel sheet having an excellent hole expandability and yield ratio, including, in terms of wt %: 0.05-0.2% of carbon (C); 2.0% or less of silicon (Si); 4.1-9.0% of manganese (Mn); 0.05% or less (excluding 0%) of phosphorus (P); 0.02% or less (excluding 0%) of sulfur (S); 0.5% or less (excluding 0%) of aluminum (Al); 0.02% or less (excluding 0%) of nitrogen (N); and a balance of iron (Fe) and other inevitable impurities, wherein the following Equation 1 is satisfied, and wherein microstructures includes, in volume percentage, 10-30% or retained austenite, 50% or more of annealed martensite, and 20% or less of other phases including alpha martensite and epsilon martensite, Equation 1: C/12+Ti/48+Nb/93+V/51+Mo/96≥0.015.

公开(公告)号：US20180363084A1

公开(公告)日：2018-12-20

申请号：US16060242

申请日：2016-12-23

Applicant: POSCO

Inventor： Sea-Woong LEE ,  Kyoo-Young LEE ,  Joo-Hyun RYU ,  Won-Hwi LEE

IPC: C21D8/02 ,  C22C38/00 ,  C22C38/06 ,  C22C38/38 ,  C22C38/14 ,  C22C38/12 ,  C22C38/02 ,  C22C38/04 ,  C23C2/06 ,  C23C2/02 ,  C21D9/46

Abstract: Provided is an ultra high-strength steel sheet having excellent hole expandability. The ultra high-strength steel sheet includes: 0.15 to 0.30% of C, 1.0 to 3.0% of Si, 3.0 to 5.0% of Mn, 0.020% or less of P, 0.010% or less of S, 0.01 to 3.0% of Al, and 0.020% or less of N (excluding 0%) by weight, with the remainder consisting of Fe and other inevitable impurities, wherein a microstructure contains 5% to 20% by area fraction of retained austenite with the remainder including ferrite, bainite and fresh martensite.