Nippon Steel Corporation

Nippin Steel Corporation

Masao Fuji

Shozo Mizoguchi

Junichi Kobayashi

Tadashi Kasuya

Shigeru Ohkita

Naoki Saitou

Toshihiko Chiba

Taketo Nakano

In order to conduct welding so that the welded steel shows a decreased residual stress after welding without a post treatment such as a PWHT, the steel for welded structures and the welding wire of the present invention starts a transformation from austenite into martensite at a temperature (Ms temperature) from at least 200&deg; C. to up to 350&deg; C., and has a yield strength from at least 60 kg/mm to up to 120 kg/mm at the transformation starting temperature. The multipass welding process of the present invention comprises forming a weld metal having a Ms temperature of 150&deg; C. to 300&deg; C., and TIG remelt-run welding the surface of the final layer.

Steel for welded structures and welding wire

In a method for continuous casting of steel, an improvement which is constituted by carrying out the continuous casting process while the thickness of a molten mold powder pool adjacent to the molten steel melt within a continuous casting mold is maintained at a desired preset value, and whenever the actual value deviates from the preset value, the continuous casting can still be continued by adjusting the casting conditions or by selecting a powder appropriate for the casting conditions. The method produces a casting requiring no subsequent processing to remove defects.

Method for continuous casting of steel

Growing community of inventors

Futtsu, Japan

Masao Fuji