A method of repairing cracks, imperfections, and the like in a cast article. A frusto-conical aperture is created in the article in the location of the crack or imperfection. A mating tapered plug is prepared such that the tapered plug can fit into the aperture so that the sloped side walls of the tapered plug evenly and unilaterally rest on frusto-conical sides of the aperture. The tapered plug is disposed into the aperture, and bonding material is applied between the surfaces of the tapered plug and the aperture, before or after insertion of the tapered plug into the aperture. The article is thereafter heated such that the bonding material joins the surfaces of the tapered plug and the aperture. The outer end of the tapered plug thereafter is polished so that such outer end is approximately level with the article's outer side in a refinement of the invention, the plug member may be pushed into the aperture such that a controlled interference fit is produced.

Method for repairing superralloy castings using a metallurgically bonded tapered plug

Aspects of the invention are related to a turbine vane assembly in which at least one of the platforms is equipped with one or more removable platform inserts. The inserts can be used in those areas of the platform where failures or damage has been known to occur, among other locations. If an insert becomes damaged or is destroyed during engine operation, the insert can be easily replaced, and the platform frames and the airfoil can be reused. As a result, the overall life of the vane can be extended. Further, the inserts can be made of materials that can reduce cooling requirements compared to known turbine vanes, thereby allowing cooling air to be used for other uses in the engine.

Turbine vane with removable platform inserts

A combustor liner has an annular shell which includes a first portion and a second portion. The first portion is provided with slot film cooling and the second portion is provided with multi-hole film cooling. The multi-hole cooling portion can be located either forward or aft of the slot film cooling portion, depending on the nature of the combustor that the liner is to be used in. In one possible embodiment, the liner includes a first annular panel, a second annular panel section joined at its forward end to the aft end of the first panel section, and a third annular panel section being joined at its forward end to the aft end of the second panel section. At least one of the panel sections has multi-hole film cooling and at least one other of the panel sections has slot film cooling.

Hybrid film cooled combustor liner

A method for applying diffusion aluminide coating on a selective area of a turbine engine component and the coating produced by that method is disclosed. A quartz infrared lamp heats only substantially the localized area of the component to be coated, rather than the complete part. Either halide activated or non-activated tape is applied on the area to be coated and is held in place during coating using a high temperature dimensionally stable tape holder manufactured from graphite or ceramic. The quartz infrared lamp is used to heat only the desired area to a coating temperature of about 1800° F. to about 2000° F. under an inert atmosphere for about 3 to about 8 hours to achieve the desired aluminide coating thickness. No powder masking of the machined surface area is required. Due to the localized heating, aluminum vapor generated from the tape will only deposit aluminide coating on the taped area.

Method for applying diffusion aluminide coating on a selective area of a turbine engine component

According to an embodiment of the invention, a method for repairing a coated high pressure turbine blade, which has been exposed to engine operation, to restore coated airfoil contour dimensions of the blade, and improve upon the prior bond coat is disclosed. The method comprises providing an engine run high pressure turbine blade including a base metal substrate made of a nickel-based alloy and having thereon a thermal barrier coating system. The thermal barrier coating system comprises a diffusion bond coat on the base metal substrate and a top ceramic thermal barrier coating comprising a yttria stabilized zirconia material. The top ceramic thermal barrier coating has a nominal thickness t. The method further comprises removing the thermal barrier coating system, wherein a portion of the base metal substrate also is removed, and determining the thickness of the base metal substrate removed. The portion of the base metal substrate removed has a thickness, Δt. The method also comprises applying a β phase NiAl overlay coating to the substrate, and determining the difference in thickness, Δx, between the β phase NiAl overlay coating and the previously removed bond coat. The method further comprises reapplying the top ceramic thermal barrier coating to a nominal thickness of t+Δt−Δx, wherein Δt compensates for the portion of removed base metal substrate. Advantageously, the coated airfoil contour dimensions of the high pressure turbine blade are restored to about the coated dimensions preceding the engine run.

Method for repairing coated components using nial bond coats

PROBLEM TO BE SOLVED: To make a moving blade and a stator blade for a gas turbine reusable by eliminating a crack generated part, then jointing an auxiliary plate of the same material as the moving blade and stator blade, to the crack eliminated part by brazing, and further laser-welding the brazed joint part surface. SOLUTION: In a method of repairing a crack generated part of a moving blade and a stator blade for a gas turbine formed of an Ni and Co base super alloy, a part of the generated crack part is eliminated by a grinder, and then an auxiliary plate 6 formed of the same material as the moving blade and stator blade and machined into a sheet state is set and jointed (7) by brazing. A brazed surface part is laser-welded (8), and the brazed part surface is reformed so that wax material components and raw material components are mixed. In this case, B-group powder of Ni: 3.5% and Si: 1.5% is inserted between raw material and the auxiliary plate 6 and jointed in vacuum. B-group powder of Ni: 23%, Co: 10%, Cr: 7%, Mo: 6% and Fe: 3% is further inserted between the raw matrial and the auxiliary plate 6 and jointed in vacuum.

Method of repairing moving blade and stator blade for gas turbine

PROBLEM TO BE SOLVED: To provide a welding method of a gas turbine rotor blade, which helps prolong the service life of the blade, and prevents the blade, as the base material, from heat cracking when reforming a blade surface, or repairing worn or eroded portion of the blade. SOLUTION: The welding method is constituted of a forwarding welding that is performed from a starting to an ending portions while the rotor blade is held heated, and a return welding that is performed from the ending to the starting portions, which completes the welding.

Welding method of gas turbine rotor blade

PURPOSE:To weld a steel material to be welded by a welding material having a strength lower than the strength of said steel undergoing restraint by welding, to cool the same, and thereafter to heat the welded part and to subject the welded parts to aging thereby to increase the strength of the soft welding joint more than the strength of the material to be welded. CONSTITUTION:A steel material to be welded such as a structure steel or the like is welded by a welding material having a strength lower than that of the steel material. In this case, welding is carried out preferably by use of a shield gas prepared by mixing 0.2 to 5% by volume of a nitrogen gas into a gas consisting more than a member selected from the group consisting of argon, helium and a carbonic acid gas. Then, the welded steel is cooled, and thereafter the welded part is heated and held at a temperature in the range of from 200 to 300 deg.C and then subjected to aging.

Steel welding method

PROBLEM TO BE SOLVED: To facilitate repair welding for cracking by repairing cracking generated on a nozzle by an overlaying layer having multilayers in a welding crosswise direction with a specified pass numbers, in a nozzle for a gas turbine provided with a blade part and a side wall. SOLUTION: In the case where cracking 30, 31 generated on a gas turbine nozzle are repaired, a multilayered overlaying layer having 3 pass or more is formed in a crosswise direction by means of TIG welding after the cracking 30, 31 are completely cut by means of carbide cutter. In the case where cracking generated o the nozzle is repaired by the overlaying layer by a gas turbine nozzle made of Co-base casting alloy including C: 0.20 to 0.30% by weight, Si: 1.0% or less, Mn: 1.0% or less, Cr: 20 to 32%, Ni: 9 to 12%, W: 5 to 10%, Fe: 5% or less, and B: 0.0005 to 0.015%, the overlaying layer is formed of Co- base alloy including C: 0.03 to 0.10% by weight, Si: 1.0% or less, Mn: 1.0% or less, Cr: 20 to 30%, Ni: 15% to 23%, W: 3 to 10%, Ta: 5 to 15%, and Zr: 0.05 to 0.7%.

Nozzle for gas turbine, gas turbine for power generation, cobalt-base alloy, and welding material

PURPOSE:To provide a weld part of dissimilar material free from the defective weld by determining the welding conditions from the relationship between the welding information and the properties of a joined part when the carbon steel is welded to the austenitic stainless steel by using the high density energy beam. CONSTITUTION:When the carbon steel is welded to the austenitic stainless steel using the high density energy beam, the welding condition is determined from the relationship between at least one information among the information on the composition of the metal to be joined, the composition of the weld metal to be added, the heat input condition during the welding, the shape of the groove, the feeding speed of the weld metal and the strength, the toughness and the fine cracks of the joined part. The structure of the metal of the joined part is preferably the mixed one of the austenitic structure and the ferritic structure of <=20%. In addition, the ratio of penetration of the base metal into the weld metal of the welded part is preferably 5 80%. It is also preferable to make control so that the width of the weld metal on the weld bead face side may be substantially equal to that of the back-bead side. This constitution provides a structure having a weld zone where no cracks are generated after welding, and the toughness is high.

Shozo Tanida

Papers

Method of repairing moving blade and stator blade for gas turbine

Welding method of gas turbine rotor blade

Steel welding method

Nozzle for gas turbine, gas turbine for power generation, cobalt-base alloy, and welding material

Welding method and welded structure using high energy beam of dissimilar material