Title:
TEMPERED MARTENSITIC STEEL HAVING LOW YIELD RATIO AND EXCELLENT UNIFORM ELONGATION, AND MANUFACTURING METHOD THEREFOR
Document Type and Number:
WIPO Patent Application WO/2018/117544
Kind Code:
A1
Abstract:
One aspect of the present invention relates to a tempered martensitic steel having a low yield ratio and an excellent uniform elongation, the tempered martensitic steel: comprising, by wt%, 0.2-0.6% of C, 0.01-2.2% of Si, 0.5-3.0% of Mn, 0.015% or less of P, 0.005% or less of S, 0.01-0.1% of Al, 0.01-0.1% of Ti, 0.05-0.5% of Cr, 0.0005-0.005% of B, 0.05-0.5% of Mo, 0.01% or less of N, and the balance of Fe and inevitable impurities; having a yield ratio of 0.4-0.6; having a product (TS*U-El), of a tensile strength and a uniform elongation, of 10,000 MPa% or more; and having a microstructure containing, by an area fraction, 90% or more of martensite, 5% or less of ferrite and the balance of bainite.
More Like This:
Inventors:
CHO YEOL-RAE (KR)
SEONG HWAN-GOO (KR)
BAE SEONG-BEOM (KR)
SEONG HWAN-GOO (KR)
BAE SEONG-BEOM (KR)
Application Number:
PCT/KR2017/014845
Publication Date:
June 28, 2018
Filing Date:
December 15, 2017
Export Citation:
Assignee:
POSCO (KR)
International Classes:
C22C38/28; C21D1/18; C21D8/02; C22C38/22; C22C38/32; C22C38/34; C22C38/38
Foreign References:
| KR20100116608A | 2010-11-01 | |||
| KR20160078850A | 2016-07-05 | |||
| JPH06108152A | 1994-04-19 | |||
| US20140322559A1 | 2014-10-30 | |||
| KR101082680B1 | 2011-11-15 | |||
| JP2006037205A | 2006-02-09 | |||
| KR20160078850A | 2016-07-05 |
Other References:
See also references of EP 3561119A4
Attorney, Agent or Firm:
C&S PATENT AND LAW OFFICE (KR)
Download PDF: