EP 3418410 A1 20181226 - SEAMLESS STEEL PIPE AND MANUFACTURING METHOD OF SAME
Title (en)
SEAMLESS STEEL PIPE AND MANUFACTURING METHOD OF SAME
Title (de)
NAHTLOSES STAHLROHR UND HERSTELLUNGSVERFAHREN DAFÜR
Title (fr)
TUYAU EN ACIER SANS SOUDURE ET SON PROCÉDÉ DE FABRICATION
Publication
Application
Priority
JP 2016054381 W 20160216
Abstract (en)
A seamless steel pipe is provided that provides a yield strength of 555 MPa or higher and good SSC resistance in a reliable manner. A seamless steel pipe contains, in mass %, C: 0.02 to 0.15 %; Si: 0.05 to 0.5 %; Mn: 0.30 to 2.5 %; Al: 0.01 to 0.10 %; Ti: 0.001 to 0.010 %; N: up to 0.007 %; Cr: 0.05 to 1.0 %; Mo: not less than 0.02 % and less than 0.5 %; Ni: 0.03 to 1.0 %; Cu: 0.02 to 1.0 %; V: 0.020 to 0.20 %; Ca: 0.0005 to 0.005 %; and Nb: 0 to 0.05 %, among others, where the carbon equivalent Ceq is not less than 0.430 % and less than 0.500 %, the main phase of the microstructure from the surface layer to an in-the-wall portion is tempered martensite or tempered bainite, the size of prior austenite grains is lower than 6.0 in crystal grain size number according to ASTM E112-10, a portion between a position at 1 mm from the inner surface and a position at 1 mm from the outer surface has a Vickers hardness of 250 Hv or lower, and the yield strength is 555 MPa or higher.
IPC 8 full level
C22C 38/00 (2006.01); C21D 8/10 (2006.01); C21D 9/08 (2006.01); C22C 38/58 (2006.01)
CPC (source: EP RU US)
C21D 6/004 (2013.01 - EP US); C21D 6/005 (2013.01 - EP US); C21D 6/008 (2013.01 - EP US); C21D 8/10 (2013.01 - EP RU); C21D 8/105 (2013.01 - EP US); C21D 9/08 (2013.01 - EP RU); C21D 9/085 (2013.01 - EP US); C22C 38/00 (2013.01 - EP US); C22C 38/001 (2013.01 - EP US); C22C 38/002 (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 38/42 (2013.01 - EP US); C22C 38/44 (2013.01 - EP US); C22C 38/46 (2013.01 - EP US); C22C 38/48 (2013.01 - EP US); C22C 38/50 (2013.01 - EP RU US); C22C 38/58 (2013.01 - EP RU US); C21D 8/10 (2013.01 - US); C21D 9/08 (2013.01 - US); C21D 2211/001 (2013.01 - EP US); C21D 2211/002 (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 3418410 A1 20181226; EP 3418410 A4 20190109; EP 3418410 B1 20210407; AU 2016393486 A1 20180426; AU 2016393486 B2 20190718; BR 112018007744 A2 20181023; BR 112018007744 B1 20210921; CA 3013287 A1 20170824; CA 3013287 C 20191231; CN 108699644 A 20181023; CN 108699644 B 20200512; JP 6112267 B1 20170412; JP WO2017141341 A1 20180222; MX 2018005240 A 20180801; RU 2706257 C1 20191115; US 2018355451 A1 20181213; WO 2017141341 A1 20170824
DOCDB simple family (application)
EP 16890483 A 20160216; AU 2016393486 A 20160216; BR 112018007744 A 20160216; CA 3013287 A 20160216; CN 201680081933 A 20160216; JP 2016054381 W 20160216; JP 2016556052 A 20160216; MX 2018005240 A 20160216; RU 2018129751 A 20160216; US 201615775409 A 20160216