EP 0725156 B1 20010718 - High ductility steel, manufacturing process and utilization
Title (en)
High ductility steel, manufacturing process and utilization
Title (de)
Stahl mit hoher Dehnbarkeit, Verfahren zur Herstellung und Verwendung
Title (fr)
Acier à haute ductilité, procédé de fabrication et utilisation
Publication
Application
Priority
FR 9501079 A 19950131
Abstract (en)
[origin: EP0725156A1] A steel alloy contains by wt. 0.15-0.35, pref. 0.20-0.24% C, 0-3, pref. 0-2.5% Si, 0-3, pref. 0.01-0.5% Al, 0.1-4.5, pref. 1.2-1.7% Mn, 0-9, pref. 1.5-2.5% Ni, 0-6, pref. 0.5-1.5% Cr, 0-0.5% V, 0-0.5% Nb, 0-0.5% Zr and less than 0.3, pref. 0.003-0.02% N. It also contains Mo and W so that Mo+W/2 is between 0 and 3, pref. 0.1 and 0.5%. The Si and Al contents add up to 1-3, pref. 1.5-2.5%. The alloy may contain 0.0005-0.005% B and 0.005-0.1% Ti. The following equation also applies: 4.6(%C) + 1.05(%Mn) + 0.54(%Ni) + 0.66(%Mo + %W/2) + 0.5(%Cr) +K ≥ 3.8, where K is 0.5 if the alloy contains B and 0 if it does not. The alloy may contain at least one of elements Ca, Se, Te, Bi and Pb in amount less than 0.2%. The remainder is Fe plus incidental impurities. Also claimed is the prodn. of the alloy, where after casting the alloy is shaped at below 1300 degrees C to final form, e.g. a sheet thicker than 8 mm. and heated to above complete austenisation temp., then cooled at more than 0.3 degrees C/s to a temp. A between M+150 degrees C and M-50 degrees C, where M is the temp. at which martensitic transformation begins. The alloy is held at temp. A for 5-90 min., then cooled to ambient at more than 0.02 degrees C/s.
IPC 1-7
IPC 8 full level
C22C 38/00 (2006.01); C22C 38/44 (2006.01); C22C 38/54 (2006.01); C22C 38/58 (2006.01)
CPC (source: EP US)
C22C 38/44 (2013.01 - EP US); C22C 38/54 (2013.01 - EP US)
Citation (examination)
EP 0709481 A1 19960501 - CREUSOT LOIRE [FR]
Designated contracting state (EPC)
DE FR GB
DOCDB simple family (publication)
EP 0725156 A1 19960807; EP 0725156 B1 20010718; DE 69613868 D1 20010823; DE 69613868 T2 20011129; FR 2729974 A1 19960802; FR 2729974 B1 19970228; JP H08239738 A 19960917; US 5695576 A 19971209
DOCDB simple family (application)
EP 96400061 A 19960111; DE 69613868 T 19960111; FR 9501079 A 19950131; JP 3740296 A 19960131; US 59073796 A 19960124