Nippon Steel Corporation

Ryoji Arima

Kazushige Umezawa

Michitaka Matsuo

Kazuumi Harashima

Tokuzo Nisugi

A method of refining a molten metal or a molten alloy through degassing, wherein a gas is blown into a molten metal or a molten alloy contained within a refining container, while stirring by utilizing an electromagnetic force, to superimpose the blown gas onto a molten metal or a molten alloy, and the stirring by an electromagnetic force, to thereby refine the blown gas, and at the same time, increase the residence time of the blown gas in the molten metal or molten alloy bath and homogeneously disperse the blown gas in the molten metal or molten alloy bath.

Method of refining molten metal or molten alloy

Molten steel in desiliconized, dephosphorized and decarburized in a three-step sequence. In the first-two steps the melt is agitated. In the first step the temperature is also maintained at between 1480.degree.-1380.degree. C. while oxygen is introduced until the silicon content is reduced to 0.20%. In the second step a flux consisting essentially of CaO and 0.2-0.5 parts by weight of CaCl.sub.2 and/or KCl is introduced while maintaining the basicity of the slag at between 3.5-8.0 and the T.Fe value at between 3-10%. The third step involves blowing oxygen onto this melt without using a refining flux.

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Futtsu, Japan

Ryoji Arima