Mitsubishi Heavy Industries Limited

Mitsubishi Jukogyo Kabushiki Kaisha

Ryotarou Magoshi

Hisataka Kawai

Yoshikuni Kadoya

Koji Takahashi

Toshio Sakon

Ichirou Tsuji

The present invention discloses ferritic heat resisting steels for manufacturing a rotor or a disk of a gas turbine, which have high creep rupture strength at high temperatures and excellent tenacity at room ordinary temperatures. The highly tenacious ferritic heat resisting steels contain, by weight, carbon of 0.08 to 0.25%, silicon of 0.5% or lower, manganese of 1.0% or lower, nickel exceeding 1.0% and lower than 3.0%, chromium of 9.0 to 12.5%, molybdenum exceeding 0.3% and lower than 1.5%, tungsten of 1.0 to 3.0%, vanadium of 0.10 to 0.35%, niobium of 0.02 to 0.10%, nitrogen of 0.01 to 0.80%, boron of 0.001 to 0.01% and cobalt of 1.0 to 5.0%, and a remaining part is mostly iron. Its structure is composed of a tempered martensite matrix.

Highly tenacious ferritic heat resisting steel

High-strength and high-toughness heat-resisting steel

There are provided high-strength and high-toughness heat-resistant cast steels applicable to steam turbine casings, precision cast vanes and valves. There is disclosed a high-strength and high-toughness heat-resistant cast steel formed of a heat-resistant cast steel consisting of, based on weight percentage: 0.08 to 0.25% of carbon; more than 0.1 not more than 0.5% of silicon; 1% or less of manganese; 0.05 to 1% of nickel; 9 to 12% of chromium; 0.3 to 1.5% of molybdenum; 1 to 1.95% of tungsten; 0.1 to 0.35% of vanadium; 0.02 to 0.1% of niobium; 0.01 to 0.08% of nitrogen; 0.001 to 0.01% of boron; and 2 to 8% of cobalt; the balance substantially being iron; and having a martensite matrix structure.

High-strength and high-toughness heat-resistant cast steel

Growing community of inventors

Hyogo-ken, Japan

Ryotarou Magoshi