EP 3282028 A1 20180214 - STEEL SHEET FOR HIGH STRENGTH LINE PIPE WITH EXCELLENT LOW TEMPERATURE TOUGHNESS AND STEEL PIPE FOR HIGH STRENGTH LINE PIPE
Title (en)
STEEL SHEET FOR HIGH STRENGTH LINE PIPE WITH EXCELLENT LOW TEMPERATURE TOUGHNESS AND STEEL PIPE FOR HIGH STRENGTH LINE PIPE
Title (de)
STAHLBLECH FÜR HOCHFESTES LEITUNGSROHR MIT HERVORRAGENDER NIEDRIGTEMPERATURBESTÄNDIGKEIT UND STAHLROHR FÜR HOCHFESTES LEITUNGSROHR
Title (fr)
TÔLE D'ACIER POUR TUBE DE CANALISATION HAUTE RÉSISTANCE AYANT UNE EXCELLENTE TÉNACITÉ À BASSE TEMPÉRATURE ET TUBE D'ACIER POUR TUBE DE CANALISATION HAUTE RÉSISTANCE
Publication
Application
Priority
- JP 2015081206 A 20150410
- JP 2016061381 W 20160407
Abstract (en)
To provide a high strength line pipe that is excellent in the low temperature toughness, particularly, in both the CTOD properties and DWTT properties. The steel sheet contains oxide particles with a circle equivalent diameter of 2 µm or more at a density of 10 particles/mm 2 or less in a t/2 position where t is a sheet thickness of the steel sheet, and the steel sheet satisfies that in the t/2 position, an average circle equivalent diameter of crystal grains enclosed by high angle grain boundaries in each of which a misorientation between two adjacent crystals is 15° or more is 10 µm or less, and that in the t/2 position, a fraction of a hard phase is 5 area% or less, while a separation index SI measured from a fracture surface of a Charpy impact test specimen of the steel sheet at a specific temperature is 0.15 mm/mm 2 or less.
IPC 8 full level
C22C 38/00 (2006.01); C21C 7/04 (2006.01); C21D 8/02 (2006.01); C22C 38/14 (2006.01); C22C 38/58 (2006.01)
CPC (source: EP KR)
C21C 7/0006 (2013.01 - EP); C21D 8/0226 (2013.01 - EP); C21D 9/46 (2013.01 - EP); C22C 38/001 (2013.01 - EP); C22C 38/002 (2013.01 - EP); C22C 38/005 (2013.01 - EP KR); C22C 38/02 (2013.01 - EP KR); C22C 38/04 (2013.01 - EP KR); C22C 38/06 (2013.01 - EP KR); C22C 38/08 (2013.01 - EP); C22C 38/12 (2013.01 - EP KR); C22C 38/14 (2013.01 - EP KR); C22C 38/16 (2013.01 - EP); C22C 38/20 (2013.01 - EP); C22C 38/22 (2013.01 - EP); C22C 38/24 (2013.01 - EP); C22C 38/26 (2013.01 - EP); C22C 38/28 (2013.01 - EP); C22C 38/42 (2013.01 - EP); C22C 38/44 (2013.01 - EP); C22C 38/46 (2013.01 - EP); C22C 38/48 (2013.01 - EP); C22C 38/50 (2013.01 - EP); C22C 38/58 (2013.01 - EP); C21C 7/04 (2013.01 - EP); C21D 8/02 (2013.01 - EP)
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 3282028 A1 20180214; EP 3282028 A4 20181107; CN 107532254 A 20180102; JP 2016199806 A 20161201; KR 20170118899 A 20171025; WO 2016163451 A1 20161013
DOCDB simple family (application)
EP 16776617 A 20160407; CN 201680020129 A 20160407; JP 2016061381 W 20160407; JP 2016076850 A 20160406; KR 20177026744 A 20160407