EP 3385401 A4 20181010 - HIGH-STRENGTH STEEL HAVING EXCELLENT BRITTLE CRACK ARRESTABILITY AND WELDING PART BRITTLE CRACK INITIATION RESISTANCE, AND PRODUCTION METHOD THEREFOR
Title (en)
HIGH-STRENGTH STEEL HAVING EXCELLENT BRITTLE CRACK ARRESTABILITY AND WELDING PART BRITTLE CRACK INITIATION RESISTANCE, AND PRODUCTION METHOD THEREFOR
Title (de)
HOCHFESTER STAHL MIT AUSGEZEICHNETER SPRÖDBRUCHSTABILITÄT UND SCHWEISSTEILSPRÖDBRUCHBESTÄNDIGKEIT UND HERSTELLUNGSVERFAHREN DAFÜR
Title (fr)
ACIER HAUTE RÉSISTANCE PRÉSENTANT D'EXCELLENTES PROPRIÉTÉS DE CAPACITÉ ANTIFISSURES FRAGILES ET DE RÉSISTANCE D'AMORÇAGE DE FISSURES FRAGILES DE PARTIE DE SOUDAGE, ET SON PROCÉDÉ DE PRODUCTION
Publication
Application
Priority
- KR 20150172689 A 20151204
- KR 2016014088 W 20161202
Abstract (en)
[origin: EP3385401A1] The purpose of another aspect of the present invention is to provide a high-strength steel having excellent brittle crack arrestability and welding part brittle crack initiation resistance, and a production method therefor. According to one aspect of the present invention, provided are a high-strength steel having excellent brittle crack arrestability and welding part brittle crack initiation resistance, and a production method therefor, the high-strength steel: comprising, in wt%, C: 0.05-0.09%, Mn: 1.5-2.2%, Ni: 0.3-1.2%, Nb: 0.005-0.04%, Ti: 0.005-0.004%, Cu: 0.1-0.8%, Si: 0.05-0.03%, Al: 0.005-0.05%, P: 100ppm or less, S: 40ppm or less, and a remainder made up by Fe and other inevitable impurities; having a center part microstructure comprising an acicular ferrite and granular bainite mixed-phase, upper bainite, and a remainder made up by one type or more selected from the group consisting of ferrite, pearlite, and a martensite-austenite (MA) constituent; having, in a 2mm or less subsurface region, a surface part microstructure comprising ferrite and a remainder made up by one type or more among bainite and martensite, and having a welding heat affected zone, which is formed during welding, that comprises, in area%, 5% or less of a martensite-austenite constituent. According to the present invention, high-strength steel having high yield strength, excellent brittle crack arrestability, and excellent welding part brittle crack initiation resistance may be obtained.
IPC 8 full level
B21B 37/16 (2006.01); C21D 8/02 (2006.01); C21D 9/46 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/06 (2006.01); C22C 38/08 (2006.01); C22C 38/12 (2006.01); C22C 38/14 (2006.01); C22C 38/16 (2006.01)
CPC (source: EP US)
C21D 8/0205 (2013.01 - EP US); C21D 8/0226 (2013.01 - EP US); C21D 8/0263 (2013.01 - EP US); C21D 9/46 (2013.01 - EP US); C22C 38/02 (2013.01 - EP US); C22C 38/04 (2013.01 - EP US); C22C 38/06 (2013.01 - EP US); C22C 38/08 (2013.01 - EP US); C22C 38/12 (2013.01 - EP US); C22C 38/14 (2013.01 - EP US); C22C 38/16 (2013.01 - EP US); C21D 2211/002 (2013.01 - EP US); C21D 2211/005 (2013.01 - EP US)
Citation (search report)
- [XI] KR 20150112489 A 20151007 - HYUNDAI STEEL CO [KR]
- [A] EP 2660346 A2 20131106 - POSCO [KR]
- See references of WO 2017095175A1
Designated contracting state (EPC)
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR
Designated extension state (EPC)
BA ME
DOCDB simple family (publication)
EP 3385401 A1 20181010; EP 3385401 A4 20181010; EP 3385401 B1 20200212; CN 108368587 A 20180803; CN 108368587 B 20200526; JP 2019502018 A 20190124; JP 6648270 B2 20200214; KR 101726082 B1 20170412; US 2018363081 A1 20181220; WO 2017095175 A1 20170608
DOCDB simple family (application)
EP 16871071 A 20161202; CN 201680070390 A 20161202; JP 2018522789 A 20161202; KR 20150172689 A 20151204; KR 2016014088 W 20161202; US 201615780175 A 20161202