EP 3385402 A1 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 SCHWEISSTEILE MIT SPRÖDBRUCHSTABILITÄT UND HERSTELLUNGSVERFAHREN DAFÜR
Title (fr)
ACIER HAUTE RÉSISTANCE PRÉSENTANT UNE EXCELLENTE APTITUDE À ARRÊTER LES FISSURES DE FRAGILITÉ ET UNE EXCELLENTE RÉSISTANCE À L'INITIATION DE FISSURES DE FRAGILITÉ D'UNE PARTIE SOUDÉE ET PROCÉDÉ POUR SA PRODUCTION
Publication
Application
Priority
- KR 20150172687 A 20151204
- KR 2016014124 W 20161202
Abstract (en)
One aspect of the present invention provides 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: 1.5-2.0%, Ni: 0.3-0.8%, Nb: 0.005-0.04%, Ti: 0.005-0.04%, Cu: 0.1-0.5%, Si: 0.05-0.3%, 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, in area%, 70% or more of acicular ferrite and 10% or more of pearlite, wherein the equivalent circular diameter of the pearlite is 15 µm (micrometers) or less; having, in a 2mm or less subsurface region, a microstructure comprising, in area%, 30% or more of one type or more among ferrite and a remainder made up by bainite, martensite, and pearlite; and having a welding heat affected zone, which is formed when 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
C22C 38/16 (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)
CPC (source: EP US)
B21B 37/16 (2013.01 - 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 2211/005 (2013.01 - EP US)
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 3385402 A1 20181010; EP 3385402 A4 20181010; EP 3385402 B1 20200408; CN 108291287 A 20180717; CN 108291287 B 20200303; JP 2019501281 A 20190117; JP 6648271 B2 20200214; KR 101736611 B1 20170517; US 2018363107 A1 20181220; WO 2017095190 A1 20170608
DOCDB simple family (application)
EP 16871086 A 20161202; CN 201680070333 A 20161202; JP 2018523418 A 20161202; KR 20150172687 A 20151204; KR 2016014124 W 20161202; US 201615780170 A 20161202