Title:
COLD-ROLLED HIGH-STRENGTH STEEL HAVING TENSILE STRENGTH OF NOT LESS THAN 1500 MPA AND EXCELLENT FORMABILITY, AND MANUFACTURING METHOD THEREFOR
Document Type and Number:
WIPO Patent Application WO/2018/076965
Kind Code:
A1
Abstract:
Provided is a cold-rolled high-strength steel having a tensile strength of not less than 1500 MPa and an excellent formability, the chemical elements thereof having the following mass percent ratios: 0.25% - 0.40% of C, 1.50% - 2.50% of Si, 2.0% - 3.0% of Mn, 0.03% - 0.06% of Al, P ≤ 0.02%, S ≤ 0.01%, N ≤ 0.01% and at least one of 0.1% - 1.0% of Cr and 0.1% - 0.5% of Mo, with the balance being Fe and other unavoidable impurities. The microstructure of the cold-rolled high-strength steel has 5% - 20% of residual austenite and 70% - 90% of martensite, and the carbon concentration ratio of the residual austenite to the martensite is greater than 3.5 and less than 15. A cold-rolled high-strength steel sheet has a high strength and an excellent formability through a rational ingredient design and microstructure control.
Inventors:
ZHOU SHU (CN)
ZHONG YONG (CN)
WANG LI (CN)
ZHONG YONG (CN)
WANG LI (CN)
Application Number:
PCT/CN2017/102384
Publication Date:
May 03, 2018
Filing Date:
September 20, 2017
Export Citation:
Assignee:
BAOSHAN IRON & STEEL (CN)
International Classes:
C22C38/02; C21D1/26; C21D8/02; C22C38/04; C22C38/06; C22C38/12; C22C38/18
Foreign References:
| CN103805840A | 2014-05-21 | |||
| CN103320700A | 2013-09-25 | |||
| CN104561793A | 2015-04-29 | |||
| JP2015224359A | 2015-12-14 | |||
| CN103805838A | 2014-05-21 | |||
| CN101624683A | 2010-01-13 | |||
| CN102227511A | 2011-10-26 | |||
| CN104160055A | 2014-11-19 |
Other References:
See also references of EP 3533894A4
Attorney, Agent or Firm:
WATSON & BAND INTELLECTUAL PROPERTY AGENT LTD. (CN)
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