EP 0952235 B1 20111012 - METHOD FOR PRODUCING HIGH-STRENGTH STEELS HAVING HIGH IMPACT ENERGY ABSORPTION PROPERTIES
Title (en)
METHOD FOR PRODUCING HIGH-STRENGTH STEELS HAVING HIGH IMPACT ENERGY ABSORPTION PROPERTIES
Title (de)
VERFAHREN ZUR HERSTELLUNG VON HOCHFESTEN STÄHLE MIT ERHÖCHTEN EIGENSCHAFTEN ZUR ABSORPTION VON AUFPRALLENERGIE
Title (fr)
PROCEDE DE FABRICATION D'ACIERS À HAUTE RESISTANCE MÈCANIQUE AYANT UNE HAUTE CAPACITE D'ABSORPTION D'ENERGIE DE CHOCK
Publication
Application
Priority
- JP 9704359 W 19971128
- JP 33138096 A 19961128
- JP 2829697 A 19970129
- JP 22300597 A 19970806
- JP 25883497 A 19970924
- JP 25888797 A 19970924
Abstract (en)
[origin: EP0952235A1] The object of the present invention is to provide high-strength steel sheets exhibiting high impact energy absorption properties, as steel materials, to be used for shaping and working into such parts as front side members of automobiles which absorb impact energy upon collision, as well as a method for their production. The high-strength steel sheets of the invention which exhibit high impact energy absorption properties are high-strength steel sheets with high flow stress during dynamic deformation characterized in that the microstructure of the steel sheets in their final form is a composite microstructure of a mixture of ferrite and/or bainite, either of which is the dominant phase, and a third phase including retained austenite at a volume fraction between 3% and 50%, wherein the average value sigma dyn (MPa) of the flow stress in the range of 3 SIMILAR 10% of equivalent strain when deformed in a strain rate range of 5 x 10<2> SIMILAR 5 x 10<3> (1/sec) after pre-deformation of greater than 0% and less than or equal to 10% of equivalent strain, satisfies the inequality: sigma dyn ≥ 0.766 x TS + 250 as expressed in terms of the maximum stress TS (MPa) in the static tensile test as measured in a strain rate range of 5 x 10<-4> SIMILAR 5 x 10<-3> (1/s) without deformation, and the work hardening coefficient between 1% and 5% of a strain is at least 0.080. <IMAGE>
IPC 8 full level
C22C 38/00 (2006.01); C21D 8/02 (2006.01); C21D 8/04 (2006.01)
CPC (source: EP KR)
C21D 8/02 (2013.01 - EP); C21D 8/0226 (2013.01 - EP); C22C 38/00 (2013.01 - KR); C21D 8/0236 (2013.01 - EP); C21D 8/0273 (2013.01 - EP); C21D 2211/001 (2013.01 - EP); C21D 2211/002 (2013.01 - EP); C21D 2211/005 (2013.01 - EP); C21D 2211/008 (2013.01 - EP)
Designated contracting state (EPC)
DE FR GB NL
DOCDB simple family (publication)
EP 0952235 A1 19991027; EP 0952235 A4 20030521; EP 0952235 B1 20111012; EP 0952235 B2 20150930; AU 5067998 A 19980622; AU 711873 B2 19991021; CA 2273334 A1 19980604; CA 2273334 C 20060328; CN 1078623 C 20020130; CN 1241219 A 20000112; EP 2314730 A1 20110427; EP 2314730 B1 20120321; KR 100318213 B1 20011222; KR 20000057266 A 20000915; TW 384313 B 20000311; WO 9823785 A1 19980604
DOCDB simple family (application)
EP 97913471 A 19971128; AU 5067998 A 19971128; CA 2273334 A 19971128; CN 97180921 A 19971128; EP 10181458 A 19971128; JP 9704359 W 19971128; KR 19997004657 A 19990526; TW 86117962 A 19971128