Nippon Steel Corporation

Ryoji Nishihara

Takeshi Kawachi

Shinichi Fukunaga

Hiroyuki Mitake

Kazuhisa Tanaka

Yuji Hiramoto

Kazunori Yasumitsu

Mitsuji Asano

A plasma torch used for heating a molten steel has an outer cylinder is provided. The torch includes a double tube, the bottom of which is blocked annularly. The torch also includes a bottomed cylindrical anode electrode that is installed within the outer cylinder with a gap existing between the anode electrode and the inside of the double tube. The plasma torch is provided such that pure copper is not used as a material for the anode electrode, the material has a softening point exceeding 150&deg; C., and the ratio of an electric conductivity D of the anode electrode to an electric conductivity N of the outer cylinder satisfies the formula: 0.2&lE;D/N<1.0. The plasma torch prevents the melting loss and wear of the anode electrode caused by the splashes and the heat produced in the anode electrode, suppresses generation of a side arc, shows an extended life, and stabilizes the casting operation and improves the quality of the slab.

Plasma torch used for heating molten steel

Growing community of inventors

Kitakyushu, Japan

Ryoji Nishihara