Molten steel refining method
AssigneeJfe Steel Corporation
InventorsAkifumi HARADA, Yoshie NAKAI
Life of this patent
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Abstract
A molten steel refining method. The method includes refining molten steel contained in a ladle by using an RH vacuum degasser. In the refining step, the surface of the molten steel circulating in a vacuum vessel of the RH vacuum degasser is subjected to a plasma treatment in which the surface of the molten steel is exposed to a hydrogen gas or an inert gas containing a hydrogen gas in the form of plasma gas under the conditions that satisfy a specified formula to reduce the amount of at least one element selected from oxygen, nitrogen, and sulfur, contained in the molten steel.
Claims16
A molten steel refining method comprising:
- refining molten steel contained in a ladle by circulating the molten steel in a vacuum vessel of an RH vacuum degasser,
- wherein in the refining, a surface of the molten steel circulating in the vacuum vessel of the RH vacuum degasser is subjected to a plasma treatment in which the surface of the molten steel is exposed to a hydrogen gas or an inert gas containing a hydrogen gas in a form of plasma gas from a plasma generator in the vacuum vessel under conditions that satisfy formula (1):
- G
- P
- ×
- (
- H
- 2
- )
- Q
- ≥
- 0
- .10
- (
- 1
- )
- where GP is a flow rate (Nm3/min) of the plasma gas, (H2) is a hydrogen gas concentration (vol %) in the plasma gas, and Q is a circulation flow rate (ton/min) of the molten steel circulating in the vacuum vessel, and
- the plasma treatment reduces an amount of at least one element selected from the group consisting of oxygen, nitrogen, and sulfur, contained in the molten steel.
Dependencies are inferred from the claim text.