Global Patent Index - EP 2133442 A4

EP 2133442 A4 20100428 - LOW-ALLOY STEEL, SEAMLESS STEEL PIPE FOR OIL WELL, AND PROCESS FOR PRODUCING SEAMLESS STEEL PIPE

Title (en)

LOW-ALLOY STEEL, SEAMLESS STEEL PIPE FOR OIL WELL, AND PROCESS FOR PRODUCING SEAMLESS STEEL PIPE

Title (de)

STAHL MIT GERINGEM LEGIERUNGSANTEIL, NAHTLOSES STAHLROHR FÜR EIN ÖLBOHRLOCH UND VERFAHREN ZUR HERSTELLUNG DES NAHTLOSEN STAHLROHRS

Title (fr)

ACIER FAIBLEMENT ALLIÉ, CONDUIT EN ACIER SANS SOUDURE POUR PUITS DE PÉTROLE ET PROCÉDÉ DE FABRICATION D'UN CONDUIT EN ACIER SANS SOUDURE

Publication

EP 2133442 A4 20100428 (EN)

Application

EP 08739231 A 20080328

Priority

  • JP 2008056113 W 20080328
  • JP 2007092144 A 20070330

Abstract (en)

[origin: EP2133442A1] A low alloy steel comprising, by mass %, C : 0.10 to 0.20%, Si : 0.05 to 1.0%, Mn : 0.05 to 1.5%, Cr : 1.0 to 2.0%, Mo : 0.05 to 2.0%, Al : 0.10 % or less and Ti : 0.002 to 0.05%, and with a Ceq value obtained by the following formula (1) of 0.65 or more, with the balance being Fe and impurities, wherein in the impurities, P is 0.025% or less, S is 0.010% or less, N is 0.007% or less, and B is less than 0.0003%, and the number per unit area of M 23 C 6 type precipitates (M: a metal element) whose grain diameter is 1 µm or more is 0.1/mm 2 or less. This invention provides a low alloy steel possessing both hardenability and toughness and improves the resistance to sulfide stress corrosion cracking. Ceq = C + Mn / 6 + Cr + Mo + V / 5 where C, Mn, Cr, Mo and V in the formula (1) denote the mass % of respective elements.

IPC 8 full level

C22C 38/00 (2006.01); C21D 8/10 (2006.01); C21D 9/08 (2006.01); C22C 38/24 (2006.01); C22C 38/28 (2006.01)

CPC (source: EP US)

C21D 6/002 (2013.01 - EP US); C21D 8/0226 (2013.01 - EP US); C21D 8/0263 (2013.01 - EP US); C21D 9/14 (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 38/22 (2013.01 - EP US); C22C 38/24 (2013.01 - EP US); C22C 38/28 (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 HR HU IE IS IT LI LT LU LV MC MT NL NO PL PT RO SE SI SK TR

DOCDB simple family (publication)

EP 2133442 A1 20091216; EP 2133442 A4 20100428; EP 2133442 B1 20120201; AT E543922 T1 20120215; AU 2008221597 A1 20081016; AU 2008221597 B2 20100401; AU 2008221597 B8 20100422; BR PI0802627 A2 20110830; BR PI0802627 B1 20170718; CA 2650208 A1 20081016; CN 101542002 A 20090923; CN 101542002 B 20160330; EA 012256 B1 20090828; EA 200870436 A1 20090227; JP 4305681 B2 20090729; JP WO2008123422 A1 20100715; MX 2008016193 A 20090415; MY 145393 A 20120131; UA 90947 C2 20100610; US 2009047166 A1 20090219; WO 2008123422 A1 20081016

DOCDB simple family (application)

EP 08739231 A 20080328; AT 08739231 T 20080328; AU 2008221597 A 20080328; BR PI0802627 A 20080328; CA 2650208 A 20080328; CN 200880000319 A 20080328; EA 200870436 A 20080328; JP 2008056113 W 20080328; JP 2008539962 A 20080328; MX 2008016193 A 20080328; MY PI20083875 A 20080328; UA A200813107 A 20080328; US 28525108 A 20081001