REFINING METHOD AND REFINING APPARATUS OF MOLTEN STEEL

Title:

REFINING METHOD AND REFINING APPARATUS OF MOLTEN STEEL

Document Type and Number:

WIPO Patent Application WO/2000/077264

Kind Code:

A1

Abstract:

A refining method of molted steel including performing decarburization refining under reduced pressure by means of immersing a lower end opening portion of a cylindrical immersion pipe having a lance into a molten steel accommodated in a ladle, sucking the molten steel by adjusting a pressure in the cylindrical immersion pipe within a predetermined range, and blowing a stirring gas toward a surface of the sucked molten steel from a bottom portion of the ladle, characterized in that the pressure Pt (Torr) in the cylindrical immersion pipe is adjusted so as to meet equations (1): Pt > 760 - 1.297 $m(x) 10?7¿ /Dc?2¿ K = 1.71 $m(x) D1?0.211¿ $m(x) Dc?0.438¿ $m(x) Wm?-1.124¿ (2): $m(x) Qg?0.519¿ $m(x) Pt?0.410-0¿ > 0.046 and oxygen gas is blown onto a surface of the molten steel through the lance, thereby performing the decarburization refining under reduced pressure. in said formulas; K: capacity coefficient regarding decarburization reaction (l/min); D1: inner diameter of ladle (cm); Dc: diameter corresponding to the circle of cylindrical immersion pipe (cm); Wm: mass of molten steel per processing (t); Qg: blown quantity of stirring gas (Nm3/h).

More Like This:

JPH10332282	DEVICE AND METHOD OR APPLYING LINING REFRACTORY FOR MOLTEN METAL CONTAINER
JP3167901	DECARBURIZATION REFINING OF CHROMIUM-CONTAINING MOLTEN STEEL

Inventors:

KUNITAKE OKITOMO (JP)
OMURA NORIO (JP)
SAKAI WATARU (JP)
MUKAWA SUSUMU (JP)
IMAI TADASHI (JP)

Application Number:

PCT/JP2000/003075

Publication Date:

December 21, 2000

Filing Date:

May 12, 2000

Export Citation:

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Assignee:

NIPPON STEEL CORP (JP)
KUNITAKE OKITOMO (JP)
OMURA NORIO (JP)
SAKAI WATARU (JP)
MUKAWA SUSUMU (JP)
IMAI TADASHI (JP)

International Classes:

C21C7/00; C21C7/064; C21C7/068; C21C7/10; (IPC1-7): C21C7/068; C21C7/064; C21C7/10

Foreign References:

JPH04285111A	1992-10-09
JPH0598340A	1993-04-20
JPH09256025A	1997-09-30
JPH09287017A	1997-11-04
JPH08109411A	1996-04-30
JPH02122013A	1990-05-09
JPH05320739A	1993-12-03
JPS62205221A	1987-09-09
JPH09287016A	1997-11-04
JPH09157730A	1997-06-17
JPH01156416A	1989-06-20
JPH1150132A	1999-02-23

Other References: