Abb Research Ltd.

Alstom

Alstom (Switzerland) Ltd

Alstom Power N.v.

Peter Ernst

Peter J Uggowitzer

Markus Speidel

Reinhard Fried

Alexander Beeck

Hannes Speidel

Ulrich Rathmann

Shailendra Naik

Kurt Faller

Alkan Goecmen

Hans-Joachim Roesler

Alkan Gocmen

Workpiece made from a chromium alloy

A heat shield of a turbo machine is provided with a microstructure. In a preferred embodiment, the microstructure element comprises a plateau, which is arranged on a rib in such a way that the structure has a &ldquo;T&rdquo;-shaped cross section. The ribs are preferably embodied as plates set on edge on the heat shield and are aligned with their surface perpendicular to the circumferential direction (U) of the turbo machine. This results in low bending dimensional rigidity in the circumferential direction. In this way, it is possible to accommodate scraping of a component involved in relative motion in the circumferential direction without plastic deformation. Moreover this arrangement gives the maximum possible resistance to a leakage flow. When used at high temperatures, it is furthermore advantageous to provide ways to enable a coolant to be supplied to the microstructure.

Turbo machine

The invention relates to a martensitic-hardenable heat-treated steel, having the following composition (data in % by weight): 9 to 13% Cr, 0.001 to 0.25% Mn, 2 to 7% Ni, 0.001 to 8% Co, at least one of W and Mo in total between 0.5 and 4%, 0.5 to 0.8% V, at least one of Nb, Ta, Zr and Hf in total between 0.001 and 0.1%, 0.001 to 0.05% Ti, 0.001 to 0.15% Si, 0.01 to 0.1% C, 0.12 to 0.18% N, at most 0.025% P, at most 0.015% S, at most 0.01% Al, at most 0.0012% Sb, at most 0.007% Sn, at most 0.012% As, remainder iron and customary impurities, and the proviso that the ratio by weight of vanadium to nitrogen V/N lies in the range between 3.5 and 4.2. After solution annealing at 1050 to 1250&deg; C., cooling to a temperature below 300&deg; C., tempering treatment, partial or complete reaustenitization at 600 to 900&deg; C., cooling to a temperature below 300&deg; C. and annealing at a temperature from 550 to 650&deg; C., it has a high resistance to heat combined, at the same time, with a high ductility.

Martensitic-hardenable heat-treated steel with improved resistance to heat and ductility

A thermally highly loaded casting is produced. The casting mold is produced from a slurry using a wax model and a polymer foam which is fixed to the wax model or has been introduced into a cavity. In this way, during the casting process the liquid superalloy also penetrates into the open-cell structure of the casting mold, so that an integral cooling structure is formed during the solidification of the casting. A single-crystal or directionally solidified casting is advantageously produced. It is also conceivable to vary the cell size of the polymer foam, to produce a cooling structure and a base material separately, and to coat the cooling structure with a ceramic protective layer (thermal barrier coating).

Process for producing a thermally loaded casting

Process for the production of a workpiece from a chromium alloy, and its use

A fully martensitic quenching and tempering steel (AP) essentially consists of (measured in % by weight): 8 to 15% of Cr, up to 15% of Co, up to 4% of Mn, up to 4% of Ni, up to 8% of Mo, up to 6% of W, 0.5 to 1.5% of V, up to 0.15% of Nb, up to 0.04% of Ti, up to 0.4% of Ta, up to 0.02% of Zr, up to 0.02% of Hf, at most 50 ppm of B, up to 0.1% of C and 0.12-0.25% of N, the content of Mn+Ni being less than 4% and the content of Mo+W being less than 8%, the remainder being iron and usual impurities resulting from smelting.

Fully martensitic steel alloy

A guide blade for steam turbines, having in the blade interior a cavity (18) to which a vacuum is applied, is provided with an opening (3) for drawing off fluid in the region of the trailing blade edge (4). This opening is provided with a porous cover (7). The cover is dimensioned in such a way that, during operation, all its capillaries are filled with the fluid to be drawn off. It is anchored in the guide blade by a mechanical fastening element (20). The mechanical fastening element (20) is a spring-loaded quick-acting lock and comprises a bush (21) which fixes the cover in the blade opening (3) and projects with its cylindrical part (24) into the blade cavity (18), and a pin (25) which is axially displaceable in the interior of the bush, is equipped with spring means (26) and is provided at its end with a cap (28), which rests on the inner wall of the blade.

Guide blade for steam turbines

Growing community of inventors

Stadel, Switzerland

Peter Ernst