Alstom Technology Limited

General Electric Technology Gmbh

Ansaldo Energia Switzerland Ag

Claus Paul Gerdes

Mohamed Youssef Nazmy

Hans Wettstein

Andreas Kuenzler

Herbert Brandl

Hans-Peter Bossmann

Sorin Keller

Werner Martin Balbach

Andreas Künzler

Mohamed Yousef Nazmy

Sven Schofer

Mohamad Nazmy

The invention relates to a method for welding rotors for power generation such as gas turbines, steam turbines, and generators having a plurality of rotor discs arranged along a rotor axis. The method includes providing said discs with a weld seam preparation. The weld seam preparation includes a root, a first, gap-like welding section adjoining the root in radial direction, and a second, gap-like welding section adjoining the first welding section in radial direction. The method further includes melting the root by means of a first welding process; making a weld in the first welding section by means of a second welding process; and filling up the second welding section by means of a third welding process.

Method for welding rotors for power generation

A nickel-base superalloy is characterized by the following chemical composition (details in % by weight): 7.7-8.3 Cr, 5.0-5.25 Co, 2.0-2.1 Mo, 7.8-8.3 W, 5.8-6.1 Ta, 4.9-5.1 Al, 1.0-1.5 Ti, 1.0-2.0 Re, 0.11-0.15 Si, 0.1-0.7 Hf, 0-0.5 Nb, 0.02-0.17 C, 50-400 ppm B, remainder Ni and production-related impurities. The alloy is distinguished by a very high resistance to oxidation, resistance to corrosion and good creep properties at high temperatures.

Nickel-based superalloy

A rotor blade () for a gas turbine includes a blade airfoil (), a blade tip (), a blade root (), and a platform () which is formed between the blade tip () and the blade root (), and is assembled from a plurality of individual sections (), the material of which is adapted in each case to the intended purpose of the individual section concerned. With such a rotor blade, a simplified production is achieved as a result of each of the individual sections () from the dimensions being significantly smaller than the assembled rotor blade ().

Rotor blade for a gas turbine

A nickel-base superalloy with improved degradation behavior consists essentially of the following chemical composition (details in % by weight): 7.7-8.3 Cr, 5.0-5.25 Co, 2.0-2.1 Mo, 7.8-8.3 W, 5.8-6.1 Ta, 4.9-5.1 Al, 1.3-1.4 Ti, 0.1-0.6 Pt, 0.1-0.5 Nb, 0.11-0.15 Si, 0.11-0.15 Hf, 200-750 ppm C, 50-400 ppm B, and the remainder Ni and production-related impurities.

Nickel-base superalloy with improved degradation behavior

In a process for producing a large single-crystal component or directionally solidified component made of a nickel-based superalloy, the component is first cast into shape in a known manner to form a microstructure comprising dendrites, and then solution annealing for homogenizing the cast microstructure of the component and two-stage precipitation heat treatment are carried out. In order to avoid chemical inhomogeneities and internal stresses caused thereby, a HIP process with a pressure of higher than 160 MPa is carried out following the solution annealing.

Process for producing a single-crystal component made of a nickel-based superalloy

The invention relates to an axial-flow thermal turbomachine having a metallic rotor (), in which rotor blades () made of an intermetallic compound are mounted in a circumferential groove to form a row of blades. The invention is characterized in that at least two rotor blades (') which are at a uniform distance from one another and are made of a more ductile material are arranged in the said row of blades between the intermetallic rotor blades (), the rotor blades (&#x2032;) made of the more ductile material either being considerably longer than the intermetallic blades () or, if they are of the same length, having a different blade tip shape than the intermetallic blades ().

Axial-flow thermal turbomachine

The invention relates to an axial-flow thermal turbomachine, having a rotor () made from a metallic material with a first density (D), in which rotor blades (') and intermediate pieces () are mounted alternately in a circumferential groove. It is characterized in that said intermediate pieces () consist of a material with a second density (D), which is lower than the first density (D). Particularly suitable materials for the intermediate pieces () are intermetallic compounds, preferably intermetallic &#x3b3;-titanium aluminide alloys or intermetallic orthorhombic titanium aluminide alloys, but also titanium alloys.

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Rütihof, Switzerland

Claus Paul Gerdes