Title:
ULTRA HIGH STRENGTH COLD ROLLED STEEL SHEET HAVING EXCELLENT SPOT WELDABILITY AND FORMABILITY, ULTRA HIGH STRENGTH PLATED STEEL SHEET AND MANUFACTURING METHOD THEREFOR
Document Type and Number:
WIPO Patent Application WO/2022/139400
Kind Code:
A1
Abstract:
The present invention provides an ultra high strength cold rolled steel sheet having excellent spot weldability and formability. The ultra high strength cold rolled steel sheet, according to one embodiment of the present invention, comprises, in weight percent,: 0.05% to 0.09% of carbon (C); 0.5% to 1.0% of silicon (Si); 2.0% to 2.8% of manganese (Mn); 0.2% to 0.5% of aluminum (Al); 0.8% to 1.2% of chromium (Cr); 0.05% to 0.10% of molybdenum (Mo); 0.03% to 0.06% of titanium (Ti); 0.001% to 0.003% of boron (B); 0.02% to 0.05% of antimony (Sb); 0.001% to 0.015% of phosphorus (P); more than 0% to 0.003% of sulfur (S); 0.004% to 0.006% of nitrogen (N); and a balance of iron (Fe) and other inevitable impurities, and the ultra high strength cold rolled steel sheet comprises a microstructure comprising ferrite and low hardness martensite.
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Inventors:
KWON SUN HWAN (KR)
PARK JIN SUNG (KR)
KIM HYE JIN (KR)
PARK JIN SUNG (KR)
KIM HYE JIN (KR)
Application Number:
PCT/KR2021/019487
Publication Date:
June 30, 2022
Filing Date:
December 21, 2021
Export Citation:
Assignee:
HYUNDAI STEEL CO (KR)
International Classes:
C22C38/60; C21D8/04; C21D9/46; C22C38/38; C23C2/06; C23C2/28
Foreign References:
| KR20140047960A | 2014-04-23 | |||
| KR20190076307A | 2019-07-02 | |||
| KR20190022769A | 2019-03-06 | |||
| KR20200120954A | 2020-10-22 | |||
| KR101630975B1 | 2016-06-16 | |||
| KR20160078570A | 2016-07-05 |
Other References:
See also references of EP 4265803A4
Attorney, Agent or Firm:
LEE, In Haeng et al. (KR)
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