EP 2546379 B1 20150429 - HIGH-STRENGTH STEEL AND HIGH-STRENGTH BOLT WITH EXCELLENT RESISTANCE TO DELAYED FRACTURE, AND MANUFACTURING METHOD THEREFOR
Title (en)
HIGH-STRENGTH STEEL AND HIGH-STRENGTH BOLT WITH EXCELLENT RESISTANCE TO DELAYED FRACTURE, AND MANUFACTURING METHOD THEREFOR
Title (de)
HOCHFESTER STAHL UND HOCHFESTER BOLZEN MIT HERVORRAGENDER BESTÄNDIGKEIT GEGEN VERZÖGERTEN BRUCH SOWIE HERSTELLUNGSVERFAHREN DAFÜR
Title (fr)
ACIER À HAUTE RÉSISTANCE ET BOULON À HAUTE RÉSISTANCE DOTÉS D'UNE EXCELLENTE RÉSISTANCE À LA RUPTURE DIFFÉRÉE ET LEUR PROCÉDÉ DE FABRICATION
Publication
Application
Priority
- JP 2010054649 A 20100311
- JP 2011056481 W 20110311
Abstract (en)
[origin: US2012247618A1] A high strength steel material which is excellent in delayed fracture resistance containing, by mass %, C: 0.10 to 0.55%, Si: 0.01 to 3%, and Mn: 0.1 to 2%, further containing one or both of V: 1.5% or less and Mo: 3.0% or less, the contents of V and Mo satisfying V+1/2Mo>0.4%, further containing one or more of Cr: 0.05 to 1.5%, Nb: 0.001 to 0.05%, Cu: 0.01 to 4%, Ni: 0.01 to 4%, and B: 0.0001 to 0.005%, and having a balance of Fe and unavoidable impurities, the structure being a mainly tempered martensite structure, the surface of the steel material being formed with (a) a nitrided layer having a thickness from the surface of the steel material of 200 μm or more and a nitrogen concentration of 12.0 mass % or less and higher than the nitrogen concentration of the steel material by 0.02 mass % or more and (b) a low carbon region having a depth from the surface of the steel material of 100 μm or more to 1000 μm or less and having a carbon concentration of 0.05 mass % or more and 0.9 time or less the carbon concentration of the steel material.
IPC 8 full level
C21D 3/04 (2006.01); C21D 9/52 (2006.01); C22C 38/12 (2006.01); C23C 8/26 (2006.01)
CPC (source: EP KR US)
C21D 8/065 (2013.01 - EP KR US); C21D 9/0093 (2013.01 - EP KR US); C21D 9/52 (2013.01 - EP US); C21D 9/525 (2013.01 - EP US); C22C 38/002 (2013.01 - EP KR US); C22C 38/02 (2013.01 - EP US); C22C 38/04 (2013.01 - EP US); C22C 38/20 (2013.01 - EP US); C22C 38/22 (2013.01 - EP US); C22C 38/24 (2013.01 - EP US); C22C 38/26 (2013.01 - EP US); C22C 38/28 (2013.01 - EP US); C22C 38/32 (2013.01 - EP US); C22C 38/34 (2013.01 - EP KR US); C22C 38/38 (2013.01 - EP US); C22C 38/40 (2013.01 - EP KR US); C22C 38/44 (2013.01 - EP KR US); C22C 38/46 (2013.01 - EP KR US); C22C 38/48 (2013.01 - EP KR US); C22C 38/50 (2013.01 - EP KR US); C22C 38/54 (2013.01 - EP KR US); C22C 38/58 (2013.01 - EP KR US); C23C 8/26 (2013.01 - EP US); C21D 2211/008 (2013.01 - EP US); C21D 2221/10 (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
DOCDB simple family (publication)
US 2012247618 A1 20121004; CN 102812145 A 20121205; EP 2546379 A1 20130116; EP 2546379 A4 20130807; EP 2546379 B1 20150429; IN 5089DEN2012 A 20151009; JP 5177323 B2 20130403; JP WO2011111872 A1 20130627; KR 101366375 B1 20140224; KR 20120056879 A 20120604; WO 2011111872 A1 20110915
DOCDB simple family (application)
US 201113515444 A 20110311; CN 201180013427 A 20110311; EP 11753527 A 20110311; IN 5089DEN2012 A 20120608; JP 2011056481 W 20110311; JP 2012502334 A 20110311; KR 20127010100 A 20110311