Nippon Steel Corporation

Tetsro Ohashi

Eiichi Takeuchi

Osamu Kitamura

Hiromu Fujii

Seizo Mineyuki

In the continuous casting of steel, it has been possible to produce killed steel industrially, but semikilled and rimmed steel have not been successfully produced due to rimming action occurring in the oscillating mold. The present invention involves a concept of suppressing the nuclei of bubbles which will later grow into CO bubbles. In order to suppress the nuclei of bubbles and to form a non-defective solidification layer of a continuously cast strand, the present invention provides a combination of: a free oxygen concentration of from 50 to 200 ppm in the molten steel; a concave shape at the short sides of the mold; a propulsion forces of the molten steel directed along the long sides of the mold in directions opposite to one another; subjecting a solidification interface to an electromagnetic flow having a speed of from 0.1 to 1.0 m/sec, and; solidifying the molten steel at the solidification interface under the influence of the electromagnetic flow, until a non-defective solidification layer without blow holes is obtained.

Growing community of inventors

Himeji, Japan

Tetsro Ohashi