EP 2518177 A4 20140319 - NITRIDING PROCESS FOR MARAGING STEEL
Title (en)
NITRIDING PROCESS FOR MARAGING STEEL
Title (de)
NITRIERUNGSVERFAHREN ZUR STAHLMARTENSITAUSHÄRTUNG
Title (fr)
PROCÉDÉ DE NITRURATION POUR ACIER MARAGING
Publication
Application
Priority
- JP 2009295131 A 20091225
- JP 2010071924 W 20101207
Abstract (en)
[origin: US2012241050A1] A nitriding process for a maraging steel is provided in order to increase the compressive residual stress of the maraging steel. A workpiece is made of maraging steel in which titanium is solid solved, and a partial amount of the titanium is oxidized at the surface of the workpiece so that titanium oxide is positively generated and concentrated at the surface. Then a reducing treatment is sufficiently performed as a pretreatment of a nitriding step, thereby removing oxygen. As a result, surface concentration of the titanium in an activated state is increased. Next, by performing the nitriding treatment, the reduced titanium and the solid solved titanium combine with nitrogen as titanium nitride. The titanium is in the activated state and is thereby easily nitrided. Moreover, the surface concentration of the titanium in the activated state is high, whereby a large amount of nitrogen infiltrates into the workpiece.
IPC 8 full level
C23C 8/26 (2006.01); C21D 1/06 (2006.01); C21D 1/68 (2006.01); C21D 1/70 (2006.01); C21D 1/72 (2006.01); C21D 6/02 (2006.01); C21D 9/40 (2006.01); C22C 38/00 (2006.01); C22C 38/08 (2006.01); C22C 38/12 (2006.01); C22C 38/52 (2006.01); C23C 8/02 (2006.01); C23C 8/50 (2006.01); C23C 8/80 (2006.01)
CPC (source: EP US)
C21D 1/68 (2013.01 - EP US); C21D 1/70 (2013.01 - EP US); C21D 1/72 (2013.01 - EP US); C21D 6/02 (2013.01 - EP US); C21D 9/40 (2013.01 - EP US); C22C 38/08 (2013.01 - EP US); C22C 38/12 (2013.01 - EP US); C23C 8/02 (2013.01 - EP US); C23C 8/26 (2013.01 - EP US); C23C 8/50 (2013.01 - EP US); C23C 8/80 (2013.01 - EP US)
Citation (search report)
- [YA] JP 2006124757 A 20060518 - TOYOTA MOTOR CORP
- [YA] EP 1544317 A1 20050622 - HONDA MOTOR CO LTD [JP]
- [A] JP 2000087214 A 20000328 - DAIDO HOXAN INC
- [A] EP 1291445 A1 20030312 - HONDA MOTOR CO LTD [JP]
- [A] US 6309474 B1 20011030 - YAGASAKI TORU [JP]
- See references of WO 2011077945A1
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 2012241050 A1 20120927; CN 102666907 A 20120912; EP 2518177 A1 20121031; EP 2518177 A4 20140319; JP 5606453 B2 20141015; JP WO2011077945 A1 20130502; WO 2011077945 A1 20110630
DOCDB simple family (application)
US 201013514062 A 20101207; CN 201080058499 A 20101207; EP 10839179 A 20101207; JP 2010071924 W 20101207; JP 2011547453 A 20101207