EP 1507016 B1 20070725 - Low-carbon free cutting steel
Title (en)
Low-carbon free cutting steel
Title (de)
Niedrig gekohlter Automatenstahl.
Title (fr)
Acier de décolletage faible teneur en carbonne.
Publication
Application
Priority
JP 2003285463 A 20030801
Abstract (en)
[origin: EP1507016A1] The invention provides a low-carbon free cutting steel containing no lead and is at least comparable in machinability to the conventional leaded free cutting steels and composite free cutting steels and furthermore has excellent finished surface characteristics. The steel is a low-carbon free cutting steel which comprises, on the percent by mass basis, C: 0.05 to under 0.20%, Mn: 0.4 - 2.0%, S: 0.21 - 1.0%, Ti: 0.002 - 0.10%, P: 0.001 - 0.30%, Al: not higher than 0.2%, O: 0.001 - 0.03% and N: 0.0005 - 0.02%, with the balance being Fe and impurities, and which satisfies the relations (a) and (b) given below concerning the inclusions contained in the steel: <DF NUM="(a),">(A + B)/C >/= 0.8 </DF> <DF NUM="(b),">NA >/= 5 </DF> wherein, A: the total area occupied by substantial MnS with Ti carbide and/or Ti carbonitride included therein among the inclusions not smaller than 1 mu m in circle-equivalent diameter per mm<2> of a cross section parallel to the direction of rolling; B: the total area occupied by substantial MnS with neither Ti carbide nor Ti carbonitride included therein among the inclusions not smaller than 1 mu m in circle-equivalent diameter per mm<2> of a cross section parallel to the direction of rolling; C: the total area occupied by all the inclusions not smaller than 1 mu m in circle-equivalent diameter per mm<2> of a cross section parallel to the direction of rolling; NA: the number of substantial MnS inclusions with Ti carbide and/or Ti carbonitride included therein among the inclusions not smaller than 1 mu m in circle-equivalent diameter per mm<2> of a cross section parallel to the direction of rolling.
IPC 8 full level
C22C 38/00 (2006.01); C22C 38/04 (2006.01); C22C 38/14 (2006.01); C22C 38/60 (2006.01)
CPC (source: EP KR US)
C22C 38/001 (2013.01 - KR); C22C 38/002 (2013.01 - KR); C22C 38/005 (2013.01 - KR); C22C 38/008 (2013.01 - KR); C22C 38/02 (2013.01 - EP US); C22C 38/04 (2013.01 - EP KR US); C22C 38/14 (2013.01 - KR); C22C 38/60 (2013.01 - KR)
Designated contracting state (EPC)
DE FR GB
DOCDB simple family (publication)
EP 1507016 A1 20050216; EP 1507016 B1 20070725; CN 1306056 C 20070321; CN 1580312 A 20050216; DE 602004007730 D1 20070906; DE 602004007730 T2 20080430; JP 2005054227 A 20050303; JP 3918787 B2 20070523; KR 100615465 B1 20060825; KR 20050016017 A 20050221; TW 200506071 A 20050216; TW I247815 B 20060121; US 2005025658 A1 20050203
DOCDB simple family (application)
EP 04254607 A 20040730; CN 200410058861 A 20040802; DE 602004007730 T 20040730; JP 2003285463 A 20030801; KR 20040057909 A 20040724; TW 93119223 A 20040629; US 89896304 A 20040727