US 7,615,099 B2
Method for producing high cleanness steel excellent in fatigue strength or cold workability
Koichi Sakamoto, Kobe (Japan); Tomoko Sugimura, Kobe (Japan); Atsuhiko Yoshida, Kobe (Japan); Yoshio Fukuzaki, Kobe (Japan); and Sumie Suda, Kobe (Japan)
Assigned to Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.), Kobe-shi (Japan)
Filed on Apr. 23, 2008, as Appl. No. 12/108,204.
Application 12/108204 is a division of application No. 10/564061, previously published as PCT/JP2004/018920, filed on Dec. 17, 2004.
Claims priority of application No. 2004-014693 (JP), filed on Jan. 22, 2004; application No. 2004-193553 (JP), filed on Jun. 30, 2004; and application No. 2004-290513 (JP), filed on Oct. 01, 2004.
Prior Publication US 2008/0202289 A1, Aug. 28, 2008
Int. Cl. C21C 7/04 (2006.01); C22C 38/18 (2006.01)
U.S. Cl. 75—570  [148/320] 11 Claims
OG exemplary drawing
 
1. A method of making a high-cleanliness steel, said method comprising adding a Li-containing substance selected from the group consisting of a Li—Si alloy having a Li content between 20 and 40% by mass, Li2CO3, and a combination thereof, to a molten steel such that the molten steel has a total-Li content between 0.020 and 9 ppm by mass.