HOT-ROLLED STEEL SHEET HAVING EXCELLENT IMPACT RESISTANCE, STEEL PIPE, MEMBER, AND MANUFACTURING METHODS THEREFOR

Title:

HOT-ROLLED STEEL SHEET HAVING EXCELLENT IMPACT RESISTANCE, STEEL PIPE, MEMBER, AND MANUFACTURING METHODS THEREFOR

Document Type and Number:

WIPO Patent Application WO/2019/132342

Kind Code:

A1

Abstract:

A preferable aspect of the present invention provides: a hot-rolled steel sheet with excellent impact resistance containing, by weight, one or two of 0.35-0.55% of C, 0.7-1.5% of Mn, 0.3% or less (excluding 0%) of Si, 0.03% or less (including 0%) of P, 0.004% or less (including 0%) of S, 0.04% or less (excluding 0%) of Al, 0.3% or less (excluding 0%) of Cr, 0.3% or less (excluding 0%) of Mo, 0.1-1.0% of Ni, and 0.1-1.0% of Cu, 0.4% or more of Cu+Ni, 0.006% or less (excluding 0%) of N, and the balance Fe and other impurities, the alloy elements satisfying relational formulas 1 to 3 below, wherein a microstructure of the hot-rolled steel sheet comprises, by volume, 10% or more of ferrite and 90% or less of perlite; a steel pipe and a member each using the same; and manufacturing methods therefor. [Relational formula 1] (Mn/Si) ≥ 3 (weight ratio) [Relational formula 2] (Ni+Cu)/(C+Mn) ≥ 0.2 (weight ratio) [Relational formula 3] (Ni/Si) ≥ 1 (weight ratio)

Inventors:

SEONG HWAN-GOO (KR)
CHO YEOL-RAE (KR)
BAE SEONG-BEOM (KR)

Application Number:

PCT/KR2018/015900

Publication Date:

July 04, 2019

Filing Date:

December 14, 2018

Export Citation:

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Assignee:

POSCO (KR)

International Classes:

C22C38/42; C21D8/02; C21D9/46; C22C38/02; C22C38/04; C22C38/44; C22C38/48

Foreign References:

KR101665819B1	2016-10-13
JP4449795B2	2010-04-14
JP2005205477A	2005-08-04
KR20160082602A	2016-07-08
KR20090124263A	2009-12-03
KR101568549B1	2015-11-11
KR20160086877A	2016-07-20
KR20060076741A	2006-07-04
KR20070068665A	2007-07-02

Other References: