Title:
STEEL HAVING FINELY DISPERSED INCLUSIONS
Document Type and Number:
WIPO Patent Application WO2004081250
Kind Code:
A3
Abstract:
An object of the invention is to provide a steel having good fatigue life characteristics and acoustic characteristics by eliminating the harmful effects of oxide based inclusions. The object is attained by the following steel. A steel having at least a part comprising: REM of which amount meets formula (1); and REM-containing inclusions of which number meets formula (2); wherein the concentration of A1203 in the REM-containing inclusions is 30 mass% or less (including 0%); Formula (1) ; -30 < REM (ppm) - (T.O (ppm)x 280/48) < 50, Formula (2) ; number of REM-containing inclusions/total number of inclusions > 0.8, wherein the inclusions of Formula (2) having an equivalent diameter of 1µm or more.
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Inventors:
HIRATA HIROSHI (JP)
ISOBE KOHICHI (JP)
ISOBE KOHICHI (JP)
Application Number:
PCT/JP2004/003251
Publication Date:
March 03, 2005
Filing Date:
March 11, 2004
Export Citation:
Assignee:
NIPPON STEEL CORP (JP)
HIRATA HIROSHI (JP)
ISOBE KOHICHI (JP)
HIRATA HIROSHI (JP)
ISOBE KOHICHI (JP)
International Classes:
C21D7/04; C21D7/06; C22C38/00; F16C33/30; C22C38/18; C22C38/28; C23C; (IPC1-7): C22C38/00; C21D7/04; C21D7/06
Foreign References:
| EP0829546A1 | 1998-03-18 |
Other References:
S. BERETTA, Y. MURAKAMI: "Largest-extreme-Value Distribution Analysis of Multiple Inclusion Types in Determining Steel Cleanliness", METALLURGICAL AND MATERIALS TRANSACTIONS B, vol. 32, no. B, June 2001 (2001-06-01), pages 517 - 523, XP008039923
P.E.WAUDBY: "Rare earht additions to steel", INTERNATIONAL METALS REVIEWS, vol. 23, no. 2, 1978, GB, pages 74 - 98, XP008033253
PATENT ABSTRACTS OF JAPAN vol. 2000, no. 04 31 August 2000 (2000-08-31)
P.E.WAUDBY: "Rare earht additions to steel", INTERNATIONAL METALS REVIEWS, vol. 23, no. 2, 1978, GB, pages 74 - 98, XP008033253
PATENT ABSTRACTS OF JAPAN vol. 2000, no. 04 31 August 2000 (2000-08-31)
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