Abstract: The precipitation hardened martensitic stainless steel is characterized by containing, in percent by weight, 12.25 to 14.25% Cr, 7.5 to 8.5% Ni, 1.0 to 2.5% Mo, 0.05% or less C, 0.2% or less Si, 0.4% or less Mn, 0.03% or less P, 0.005% or less S, 0.008% or less N, 0.90 to 2.25% Al, the balance substantially being Fe, and the total content of Cr and Mo being 14.25 to 16.75%. A turbine moving blade and a steam turbine are manufactured by using this martensitic stainless steel.

Abstract: The precipitation hardened martensitic stainless steel is characterized by containing, in percent by weight, 12.25 to 14.25% Cr, 7.5 to 8.5% Ni, 1.0 to 2.5% Mo, 0.05% or less C, 0.2% or less Si, 0.4% or less Mn, 0.03% or less P, 0.005% or less S, 0.008% or less N, 0.90 to 2.25% Al, the balance substantially being Fe, and the total content of Cr and Mo being 14.25 to 16.75%. A turbine moving blade and a steam turbine are manufactured by using this martensitic stainless steel.

Abstract: A stationary blade and a steam turbine capable of reducing self-excited vibrations with a simple configuration are provided. A stationary blade has a cavity, extending in a blade-width direction, formed therein and slits communicating between the cavity and the outside. A wave-shaped plate spring that is in sliding contact with at least one of a pressure-side member and a suction-side member is provided between the pressure-side member, which is a portion on the pressure side of the cavity, and the suction-side member, which is a portion on the suction side of the cavity. When the stationary blade is elastically deformed, the wave-shaped plate spring causes friction between itself and at least one of the pressure-side member and the suction-side member. This friction attenuates relative positional displacement between the pressure-side member and the suction-side member. Thus, self-excited vibrations occurring at the stationary blade can be reduced.

Abstract: The turbine is provided with a blade (50) and a structure body (11) which rotates relatively with respect to the blade (50). A stepped part (52A) having a step surface (53A) is installed at one of the leading end of the blade (50) and the structure body (11) corresponding to the leading end thereof, while a seal fin (15A) which extends toward the stepped part (52A) to form a small space (H) is installed at the other of them. A cavity (C1) is formed between the blade (50) and the structure body (11) and also between the seal fin (15A) and the partition wall which faces thereto in the rotating shaft direction of the structure body (11) on the upstream side. When a distance of the cavity (C1) between the partition wall and the seal fin (15A) is given as a cavity width (W), and a distance between the seal fin (15A) and the end edge (55) of the stepped part (52A) in the rotating shaft direction on the upstream side is given as (L), at least one of the distances (L) satisfies the following formula (1). 0.7H?L?0.

Abstract: The turbine is provided with a blade (50) and a structure body (11) which rotates relatively with respect to the blade (50). A stepped part (52A) having a step surface (53A) is installed at one of the leading end of the blade (50) and the structure body (11) corresponding to the leading end thereof, while a seal fin (15A) which extends toward the stepped part (52A) to form a small space (H) is installed at the other of them. A cavity (C1) is formed between the blade (50) and the structure body (11) and also between the seal fin (15A) and the partition wall which faces thereto in the rotating shaft direction of the structure body (11) on the upstream side. When a distance of the cavity (C1) between the partition wall and the seal fin (15A) is given as a cavity width (W), and a distance between the seal fin (15A) and the end edge (55) of the stepped part (52A) in the rotating shaft direction on the upstream side is given as (L), at least one of the distances (L) satisfies the following formula (1). 0.7H?L?0.

Abstract: A stationary blade and a steam turbine capable of reducing self-excited vibrations with a simple configuration are provided. A stationary blade has a cavity, extending in a blade-width direction, formed therein and slits communicating between the cavity and the outside. A wave-shaped plate spring that is in sliding contact with at least one of a pressure-side member and a suction-side member is provided between the pressure-side member, which is a portion on the pressure side of the cavity, and the suction-side member, which is a portion on the suction side of the cavity. When the stationary blade is elastically deformed, the wave-shaped plate spring causes friction between itself and at least one of the pressure-side member and the suction-side member. This friction attenuates relative positional displacement between the pressure-side member and the suction-side member. Thus, self-excited vibrations occurring at the stationary blade can be reduced.

Abstract: The precipitation hardened martensitic stainless steel is characterized by containing, in percent by weight, 12.25 to 14.25% Cr, 7.5 to 8.5% Ni, 1.0 to 2.5% Mo, 0.05% or less C, 0.2% or less Si, 0.4% or less Mn, 0.03% or less P, 0.005% or less S, 0.008% or less N, 0.90 to 2.25% Al, the balance substantially being Fe, and the total content of Cr and Mo being 14.25 to 16.75%. A turbine moving blade and a steam turbine are manufactured by using this martensitic stainless steel.