Global Patent Index - EP 1746175 A4

EP 1746175 A4 20070704 - SUPER HIGH STRENGTH UOE STEEL PIPE AND METHOD FOR PRODUCTION THEREOF

Title (en)

SUPER HIGH STRENGTH UOE STEEL PIPE AND METHOD FOR PRODUCTION THEREOF

Title (de)

SUPERHOCHFESTES UOE-STAHLROHR UND HERSTELLUNGSVERFAHREN DAFÜR

Title (fr)

TUBE D"ACIER UOE D"ULTRAHAUTE RÉSISTANCE ET PROCÉDÉ DE FABRICATION DE CELUI-CI

Publication

EP 1746175 A4 20070704 (EN)

Application

EP 05739174 A 20050510

Priority

  • JP 2005008503 W 20050510
  • JP 2004141223 A 20040511

Abstract (en)

[origin: EP1746175A1] A UOE steel pipe for use in linepipe having an ultrahigh strength in the circumferential direction of the pipe of at least 750 MPa and at most 900 MPa and having improved toughness in the base metal and weld heat affected zone along with improved joint fracture properties and good circumferential weldability is manufactured from a hot-rolled steel plate having a composition comprising, in mass percent, C: 0.03 - 0.08%, Mn: 1.70 - 2.2%, S: at most 0.0020%, Ti: 0.005 - 0.025%, N: at most 0.0050% and having a carbon equivalent (Ceq) as defined below of at least 0.50% and a weld cracking parameter (Pcm) as defined below of at most 0.24% wherein the temperature at the completion of water cooling after hot rolling is 350° C or higher: Ceq = C + Mn / 6 + Cr + Mo + V / 5 + Cu + Ni / 15 , Pcm = C + Si / 30 + Mn / 20 + Cu / 20 + Ni / 60 + Cr / 20 + Mo / 15 + V / 10 + B .

IPC 8 full level

C22C 38/00 (2006.01); B21C 37/08 (2006.01); C21D 8/02 (2006.01); C21D 8/10 (2006.01); C22C 38/14 (2006.01); C22C 38/58 (2006.01)

CPC (source: EP US)

B21C 37/08 (2013.01 - EP US); C21D 8/0226 (2013.01 - EP US); C21D 8/10 (2013.01 - EP US); C22C 38/02 (2013.01 - EP US); C22C 38/42 (2013.01 - EP US); C22C 38/44 (2013.01 - EP US); C22C 38/58 (2013.01 - EP US)

Citation (search report)

Designated contracting state (EPC)

AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU MC NL PL PT RO SE SI SK TR

DOCDB simple family (publication)

EP 1746175 A1 20070124; EP 1746175 A4 20070704; CA 2566425 A1 20051117; CN 1977059 A 20070606; JP WO2005108636 A1 20080321; US 2007240794 A1 20071018; WO 2005108636 A1 20051117

DOCDB simple family (application)

EP 05739174 A 20050510; CA 2566425 A 20050510; CN 200580021313 A 20050510; JP 2005008503 W 20050510; JP 2006513023 A 20050510; US 59802206 A 20061113