EP 2135962 A1 20091223 - CASE-HARDENED STEEL PIPE EXCELLENT IN WORKABILITY AND PROCESS FOR PRODUCTION THEREOF
Title (en)
CASE-HARDENED STEEL PIPE EXCELLENT IN WORKABILITY AND PROCESS FOR PRODUCTION THEREOF
Title (de)
EINSATZGEHÄRTETES STAHLROHR MIT HERVORRAGENDER BEARBEITBARKEIT UND HERSTELLUNGSVERFAHREN DAFÜR
Title (fr)
TUYAU EN ACIER CÉMENTÉ AYANT UNE EXCELLENTE APTITUDE AU FAÇONNAGE ET SON PROCÉDÉ DE FABRICATION
Publication
Application
Priority
- JP 2008056016 W 20080328
- JP 2007088283 A 20070329
Abstract (en)
A case hardening steel tube which has a hardness of 72 - 80 HRB and which gives a carburized layer with a high strength and high wear resistance and adequate resistance to impact fracture when it is formed into a final product by working and subsequent carburizing and quenching under relatively mild conditions is manufactured by forming a tube from a steel having a steel composition comprising, in mass percent, C: 0.1 - 0.25%, Si: 0.2 - 0.4%, Mn: 0.3 - 0.9%, P: at most 0.02%, S: 0.001 - 0.15%, Cr: 0.5 - 0.9%, Mo: 0.15 - 1%, Al: 0.01 - 0.1%, B: 0.0005 - 0.009%, N: less than 0.006%, and a remainder essentially of Fe, then subjecting the resulting steel tube to normalizing by soaking at a temperature of 880 - 980 °C followed by cooling at a cooling rate of at most 70 °C per minute, carrying out cold working of the normalized steel tube, and then annealing the cold worked steel tube at a temperature of 700 - 820 °C.
IPC 8 full level
C21D 1/28 (2006.01); C21D 1/32 (2006.01); C21D 6/02 (2006.01); C21D 7/04 (2006.01); C21D 8/10 (2006.01); C21D 9/08 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/06 (2006.01); C22C 38/22 (2006.01); C22C 38/24 (2006.01); C22C 38/26 (2006.01); C22C 38/28 (2006.01); C22C 38/32 (2006.01); C23C 8/02 (2006.01); C23C 8/46 (2006.01); C23C 8/80 (2006.01)
CPC (source: EP KR US)
C21D 1/28 (2013.01 - EP KR US); C21D 1/32 (2013.01 - EP KR US); C21D 6/02 (2013.01 - EP KR US); C21D 7/04 (2013.01 - EP KR US); C21D 8/10 (2013.01 - EP US); C21D 8/105 (2013.01 - EP KR US); C21D 9/085 (2013.01 - EP US); C22C 38/02 (2013.01 - EP KR US); C22C 38/04 (2013.01 - EP KR US); C22C 38/06 (2013.01 - EP KR US); C22C 38/22 (2013.01 - EP US); C22C 38/24 (2013.01 - EP KR US); C22C 38/26 (2013.01 - EP US); C22C 38/28 (2013.01 - EP KR US); C22C 38/32 (2013.01 - EP KR US); C22C 38/44 (2013.01 - EP US); C22C 38/48 (2013.01 - EP US); C22C 38/50 (2013.01 - EP US); C22C 38/60 (2013.01 - EP US); C23C 8/02 (2013.01 - EP US); C23C 8/46 (2013.01 - EP US); C23C 8/80 (2013.01 - EP US); C21D 2211/003 (2013.01 - EP US); C21D 2211/005 (2013.01 - EP US)
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 2135962 A1 20091223; EP 2135962 A4 20150304; EP 2135962 B1 20160713; CN 101646788 A 20100210; CN 101646788 B 20110413; JP 5126857 B2 20130123; JP WO2008123397 A1 20100715; KR 101113575 B1 20120313; KR 20090125134 A 20091203; MX 2009010307 A 20091016; US 2010051143 A1 20100304; WO 2008123397 A1 20081016
DOCDB simple family (application)
EP 08739140 A 20080328; CN 200880010517 A 20080328; JP 2008056016 W 20080328; JP 2009509185 A 20080328; KR 20097019966 A 20080328; MX 2009010307 A 20080328; US 55735309 A 20090910