Nippon Steel Corporation

Mitsubishi Jukogyo Kabushiki Kaisha

Abb Research Ltd.

Asea Brown Boveri Inc.

Peter Ernst

Yasushi Hasegawa

Fujimitsu Masuyama

Christoph Tonnes

Jakob Rhyner

Manfred Thumann

In a device for damping blade vibrations of an axial-flow turbomachine, the ends of the rotating blades form a seal toward the flow-limiting wall of a turbine casing. A ring of permanently magnetic material is attached to this flow-limiting wall of the turbine casing in the radial direction opposite the blade ends, which ring consists of at least one or more sectional rings of the same or different magnetic polarization. The blade ends are each provided with a cover plate which is made of a material which is a good electrical conductor.

Vibration damping for turbine blades

A turbine blade including a blade foot and a blade. The blade foot is formed by a ductile material and the blade comprises a material which is brittle compared to the ductile material but resistant to high temperature. The two materials are alloys of different chemical compositions and are hot-compacted with the formation of a boundary layer joining the blade foot and blade to produce a bimetallic composite material. The blade foot predominantly comprises a titanium-base alloy and the blade comprises a gamma-titanium aluminide containing 0.5 to 8 atomic percent of a dopant. The turbine blade exhibits outstanding mechanical properties at high temperatures, good ductility at room temperature and a long service life.

Component, in particular turbine blade which can be exposed to high

A high-nitrogen ferritic heat-resisting steel comprises, in weight percent, 0.01-0.30% C, 0.02-0.80% Si, 0.20-1.00% Mn, 8.00-13.00% Cr, 0.50-3.00% W, 0.005-1.00% Mo, 0.05-0.50% V, 0.02-0.12% Nb and 0.10-0.50% N and is controlled to include not more than 0.050% P, not more than 0.010% S and not more than 0.020% O, the balance being Fe and unavoidable impurities. The steel may optionally comprise (A) one or both of 0.01-1.00% Ta and 0.01-1.00% Hf and/or (B) one or both of 0.0005-0.10% Zr and 0.01-0.10% Ti. A method of producing the steel comprises melting and equilibrating the steel components in an atmosphere of a mixed gas of a prescribed nitrogen partial pressure or nitrogen gas and thereafter casting or solidifying the melt in an atmosphere controlled to have a nitrogen partial pressure of not less than 1.0 ata and a total pressure of not less than 4.0 ata, with the relationship between the partial pressure p and the total pressure P.sub.t being

Method of production of high-nitrogen ferritic heat-resisting steel

A high-nitrogen ferritic heat-resisting steel comprises, in weight per cent, 0.01-0.30% C, 0.02-0.80% Si, 0.20-1.00% Mn, 8.00-13.00% Cr, 0.50-3.00% W, 0.005-1.00% Mo, 0.05-0.50% V, 0.02-0.12% Nb and 0.10-0.50% N and is controlled to include not more than 0.050% P, not more than 0.010% S and not more than 0.020% O, the balance being Fe and unavoidable impurities. The steel may optionally comprise (A) one or both of 0.01-1.00% Ta and 0.01-1.00% Hf and/or (B) or both of 0.0005-0.10% Zr and 0.01-0.10% Ti. A method of producing the steel comprises melting and equilibrating the steel components in an atmosphere of a mixed gas of a prescribed nitrogen partial pressure or nitrogen gas and thereafter casting or solidifying the melt in an atmosphere controlled to have a nitrogen partial pressure of not less than 1.0 ata and a total pressure of not less than 4.0 ata, with the relationship between the partial pressure p and the total pressure P.sub.t being

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Peter Ernst