| (19) |
 |
|
(11) |
EP 1 389 639 A3 |
| (12) |
EUROPEAN PATENT APPLICATION |
| (88) |
Date of publication A3: |
|
08.06.2005 Bulletin 2005/23 |
| (43) |
Date of publication A2: |
|
18.02.2004 Bulletin 2004/08 |
| (22) |
Date of filing: 24.07.2003 |
|
|
| (84) |
Designated Contracting States: |
|
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PT RO SE SI SK TR |
|
Designated Extension States: |
|
AL LT LV MK |
| (30) |
Priority: |
29.07.2002 JP 2002219662
|
| (71) |
Applicant: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.) |
|
Kobe-shi, Hyogo 651-8585 (JP) |
|
| (72) |
Inventors: |
|
- Ikeda, Shushi, c/o Kobe Steel, Ltd.
Kobe-shi, Hyogo 651-2271 (JP)
- Makii, Koichi, c/o Kobe Steel, Ltd.
Kobe-shi, Hyogo 651-2271 (JP)
- Akamizu, Hiroshi, c/o Kobe Steel, Ltd
Kobe-shi, Hyogo 651-2271 (JP)
|
| (74) |
Representative: Gillard, Richard Edward |
|
Elkington and Fife LLP, Prospect House 8 Pembroke Road
Sevenoaks, Kent TN13 1XR
Sevenoaks, Kent TN13 1XR (GB) |
|
| |
|
| (54) |
Steel sheet with excellent bendability |
(57) A steel sheet with excellent bendability in which the main structure is composed
of retained austenite (5-30 area%) and ferrite (no less than 50 area%) such that there
exist no more than 40 carbide grains per 2000 µm
2 between the retained austenite and the ferrite. The steel sheet is suitable for automobiles
which exhibits bending properties (bendability and tight bendability) even though
its strength is as high as 600 to 1400 MPa.