Method for producing steel ingot
AssigneeHitachi Metals, Ltd.
InventorsKen-ichiro Hara, Hidemi Takao, Setsuo Mishima, Etsuo Fujita
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Abstract
A method for producing a steel ingot, which comprises an Mg oxide forming step of preparing a molten steel containing Mg in an amount sufficient for the molten steel to have an oxide composition having MgO as a primary component and a dissociation step of keeping the pressure of the atmosphere around the molten steel to be lower than that in the Mg oxide forming step, to thereby dissociate MgO to Mg and oxygen and reduce the content of Mg in the steel to 50% or less of that in the Mg oxide forming step through the diffusion thereof into a gas phase. A preferred method further involves a solidifying step.
Claims15
A method of producing a steel ingot, which comprises the steps of:
- preparing molten steel under vacuum;
- forming magnesium oxides by adding Mg into the molten steel in order to make oxides contained in the molten steel so as to have a chemical composition a primary component of which is MgO;
- subsequently producing a consumable electrode from the molten steel containing magnesium oxides;
- and
- remelting the consumable electrode under higher vacuum than that of the former process of forming the magnesium oxides in order to dissociate the magnesium oxides contained in the molten steel into Mg and oxygen, thereby making a Mg content in the molten steel to be not more than 50% of that in the former process of forming magnesium oxides.
Dependencies are inferred from the claim text.