EP 4079908 A1 20221026 - LEAF SPRING STEEL SHEET HAVING EXCELLENT FATIGUE LIFE, AND MANUFACTURING METHOD THEREFOR
Title (en)
LEAF SPRING STEEL SHEET HAVING EXCELLENT FATIGUE LIFE, AND MANUFACTURING METHOD THEREFOR
Title (de)
BLATTFEDERSTAHLBLECH MIT AUSGEZEICHNETER ERMÜDUNGSLEBENSDAUER UND VERFAHREN ZU SEINER HERSTELLUNG
Title (fr)
FEUILLE D'ACIER À RESSORT À LAMES PRÉSENTANT UNE EXCELLENTE DURÉE DE VIE EN FATIGUE ET SON PROCÉDÉ DE FABRICATION
Publication
Application
Priority
- KR 20190171858 A 20191220
- KR 2020017990 W 20201210
Abstract (en)
A leaf spring steel sheet according to one aspect of the present invention comprises, by wt%, 0.7-1.0% of carbon (C), 0.1-0.4% of silicon (Si), 0.2-1.0% of manganese (Mn), 0.05-2.0% of chromium (Cr), 0.07-0.2% of vanadium (V), 0.03% or less of phosphorus (P), 0.03% or less of sulfur (S) and the balance of Fe and inevitable impurities, wherein the steel sheet comprises, as a microstructure, 99 area% or more of pearlite and 1 area% or less (excluding 0%) of vanadium carbide (VC), and the average particle size of prior austenite can be 28 µm or less.
IPC 8 full level
B21B 1/24 (2006.01); B21B 3/00 (2006.01); C21D 8/12 (2006.01); C22C 38/24 (2006.01)
CPC (source: EP KR)
B21B 1/24 (2013.01 - KR); B21B 3/00 (2013.01 - KR); C21D 1/19 (2013.01 - EP); C21D 1/26 (2013.01 - EP); C21D 1/32 (2013.01 - EP); C21D 1/46 (2013.01 - EP); C21D 8/0205 (2013.01 - EP); C21D 8/0226 (2013.01 - EP); C21D 8/0236 (2013.01 - EP); C21D 8/0263 (2013.01 - EP); C21D 8/1222 (2013.01 - KR); C21D 8/1233 (2013.01 - KR); C21D 9/02 (2013.01 - EP); C21D 9/46 (2013.01 - EP); C22C 38/02 (2013.01 - EP); C22C 38/04 (2013.01 - EP); C22C 38/18 (2013.01 - EP); C22C 38/24 (2013.01 - EP KR); C21D 2211/001 (2013.01 - KR); C21D 2211/009 (2013.01 - EP KR)
Citation (search report)
See references of WO 2021125688A1
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
Designated extension state (EPC)
BA ME
Designated validation state (EPC)
KH MA MD TN
DOCDB simple family (publication)
EP 4079908 A1 20221026; CN 114846170 A 20220802; KR 102327929 B1 20211117; KR 20210079746 A 20210630; WO 2021125688 A1 20210624
DOCDB simple family (application)
EP 20902722 A 20201210; CN 202080088945 A 20201210; KR 20190171858 A 20191220; KR 2020017990 W 20201210