EP 1900838 A1 20080319 - STEEL FOR MECHANICAL STRUCTURE EXCELLING IN STRENGTH, DUCTILITY AND TOUGHNESS AND PROCESS FOR PRODUCING THE SAME
Title (en)
STEEL FOR MECHANICAL STRUCTURE EXCELLING IN STRENGTH, DUCTILITY AND TOUGHNESS AND PROCESS FOR PRODUCING THE SAME
Title (de)
STAHL FÜR EINE MECHANISCHE STRUKTUR MIT HERVORRAGENDER FESTIGKEIT, BIEGBARKEIT UND HÄRTE SOWIE HERSTELLUNGSVERFAHREN DAFÜR
Title (fr)
ACIER POUR STRUCTURE MÉCANIQUE EXCELLENT EN MATIÈRE DE RÉSISTANCE, DUCTILITÉ ET TÉNACITÉ ET SON PROCÉDÉ DE FABRICATION
Publication
Application
Priority
- JP 2006313521 W 20060630
- JP 2005195739 A 20050705
- JP 2005326844 A 20051111
- JP 2006079070 A 20060322
Abstract (en)
A steel for machine structural use with a better strength-ductility-toughness balance than maraging steel and applications thereof are provided. The steel for machine structural use with excellent strength, ductility, and toughness contains, in percent by mass, more than 0.30% to 0.5% of carbon, 1.0% or less of silicon, 1.5% or less of manganese, 0.025% or less of aluminum, 0.3% to 0.5% of molybdenum, and 0.0005% to 0.01% of boron, and the balance is iron and incidental impurities. The steel has a structure including at least 90% by volume of martensitic structure. The martensitic structure includes blocks having a size of 1.5 µm or less. Dissolved boron is contained in an amount of at least 0.0005% and is present at boundaries of prior austenite grains in a concentration at least 1.5 times that in the prior austenite grains.
IPC 8 full level
C22C 38/00 (2006.01); C21D 9/40 (2006.01); C21D 9/46 (2006.01)
CPC (source: EP KR US)
C21D 1/18 (2013.01 - KR); C21D 9/46 (2013.01 - EP US); C22C 38/00 (2013.01 - EP US); C22C 38/02 (2013.01 - KR); C22C 38/04 (2013.01 - KR); C22C 38/06 (2013.01 - KR); C22C 38/12 (2013.01 - KR); C21D 2211/008 (2013.01 - KR)
Designated contracting state (EPC)
DE FR GB NL
DOCDB simple family (publication)
US 2008017283 A1 20080124; EP 1900838 A1 20080319; EP 1900838 A4 20090325; JP 2007154305 A 20070621; KR 100945313 B1 20100308; KR 20070088766 A 20070829; TW 200710227 A 20070316; TW I321590 B 20100311; WO 2007004707 A1 20070111
DOCDB simple family (application)
US 79519206 A 20060630; EP 06780846 A 20060630; JP 2006079070 A 20060322; JP 2006313521 W 20060630; KR 20077015294 A 20060630; TW 95124422 A 20060705