EP 3546610 B1 20210616 - AS-ROLLED ELECTRIC RESISTANCE WELDED STEEL PIPE FOR LINE PIPE
Title (en)
AS-ROLLED ELECTRIC RESISTANCE WELDED STEEL PIPE FOR LINE PIPE
Title (de)
WIDERSTANDSGESCHWEISSTES STAHLROHR IM WALZZUSTAND FÜR LEITUNGSROHRE
Title (fr)
TUYAU EN ACIER SOUDÉ PAR RÉSISTANCE ÉLECTRIQUE TEL QUE LAMINÉ POUR TUYAUX DE CANALISATION
Publication
Application
Priority
JP 2017013013 W 20170329
Abstract (en)
[origin: EP3546610A1] An as-rolled electric resistance welded steel pipe for a line pipe has a base metal portion that includes, in terms of % by mass, 0.01 to 0.10% of C, 0.01 to 0.40% of Si, 0.50 to 2.00% of Mn, 0 to 0.030% of P, 0 to 0.0015% of S, 0.010 to 0.050% of Al, 0.0030 to 0.0080% of N, 0.010 to 0.050% of Nb and 0.005 to 0.020% of Ti, the balance comprising Fe and impurities, and in a metallographic microstructure of the base metal portion, an areal ratio of polygonal ferrite is 80% to 98% and the balance is composed of at least one of bainite or pearlite, a yield strength in a pipe axis direction is 415 to 550 MPa, a tensile strength in the pipe axis direction is 461 to 625 MPa, and a maximum Vickers hardness of an inner surface layer of the base metal portion is 248 HV or less and is smaller than a maximum Vickers hardness of an outer surface layer of the base metal portion by 5 HV or more.
IPC 8 full level
C22C 38/00 (2006.01); C21D 8/10 (2006.01); C21D 9/08 (2006.01); C21D 9/50 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/12 (2006.01); C22C 38/14 (2006.01)
CPC (source: EP KR)
C21D 8/10 (2013.01 - EP); C21D 8/105 (2013.01 - KR); C21D 9/08 (2013.01 - EP KR); C21D 9/50 (2013.01 - EP KR); C22C 38/00 (2013.01 - EP); C22C 38/001 (2013.01 - EP); C22C 38/04 (2013.01 - EP); C22C 38/12 (2013.01 - EP); C22C 38/14 (2013.01 - EP); C22C 38/58 (2013.01 - EP KR); C21D 2211/005 (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
DOCDB simple family (publication)
EP 3546610 A1 20191002; EP 3546610 A4 20200429; EP 3546610 B1 20210616; CN 110088317 A 20190802; JP 6288390 B1 20180307; JP WO2018179169 A1 20190404; KR 20190084092 A 20190715; WO 2018179169 A1 20181004
DOCDB simple family (application)
EP 17904175 A 20170329; CN 201780077913 A 20170329; JP 2017013013 W 20170329; JP 2017549548 A 20170329; KR 20197016507 A 20170329