Nippon Steel Corporation

Takamasa Ohno

Yasushi Nakamura

Masaki Okajima

Koichi Chiba

Akihiro Ono

Hiroyuki Katayama

Hidetake Ishikawa

Hiroyuki Kajioka

Makoto Inatomi

Michihisa Itou

Hiroshi Yamane

Michihisa Ito

Kazuumi Harashima

Minoru Hayata

Oxygen or a mixed gas containing oxygen, or a chemical flame produced by a mixture of a combustion gas and a combustion-assisting gas containing oxygen, is blown against the surface of molten iron to cause radiation emission. The radiations are divided into components of different wavelengths, and the resulting emission spectra are measured to determine the composition of the molten iron.

Method of spectroscopically determining the composition of molten iron

A carbon-unsaturated molten metal or molten alloy containing elements more oxidizable than iron such as chromium and silicon is dephosphorized by addition of a flux composition comprising calcium carbide and a halide of alkali earth metal such as calcium fluoride in a non-oxidizing atmosphere, and thereafter the slag as a by-product is stabilized against formation of undesirable gases. This method when employed in refining ferrochromium or crude stainless steel makes feasible dephosphorization, and it is particularly suited for economical production of low phosphorus stainless steel.

Method of dephosphorization of metal or alloy

Cr alloy, Mn alloy or Mo alloy can be dephosphorized and denitrified simultaneously with a flux newly prepared. The flux comprises metallic Ca, Mg, Ba or Sr and halides thereof. There is no loss of valuable alloying component in this method.

Method for dephosphorization and denitrification of an alloy containing

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Hikari, Japan

Takamasa Ohno