Electric Power Research Institute Incorporated

Ramaswamy Viswanathan

David Wayne Gandy

Kent Coleman

Gregory J Frederick

Artie Gene Peterson, Jr

William Frederick Newell, Jr

Jan T Stover

Shane J Findlan

James W Hales

James Franklin Turner

Roger Allen Swain

Ronald E Munson

Kent K Coleman

David W Gandy

William F Newell

In one embodiment, the present invention provides a method for welding together two metal pieces, comprising buttering a surface of a first metal piece with a first nickel-based filler metal at a thickness sufficient to isolate a heat-affected zone in the first metal piece from subsequent welding; heat-treating at least the heat-affected zone in the first metal piece; buttering a surface of a second metal piece with a second nickel-based filler metal having the same composition as the first nickel-based filler metal and at a thickness sufficient to isolate a heat-affected zone in the second metal piece from subsequent welding; heat-treating at least the heat-affected zone in the second metal piece; and welding the heat-treated first buttered surface to the heat-treated second buttered surface with a third nickel-based filler metal having the same composition as the first and second nickel-based filler metals.

Methods for extending the life of alloy steel welded joints by elimination and reduction of the HAZ

Accordingly, the present invention provides a weld filler composition for joining different alloy steel pieces with substantially different chromium content, such as joining low alloy ferritic steel to high alloy ferritic steel, low alloy ferritic steel to austenitic stainless steel, or high alloy ferritic steel to austenitic stainless steel, and a method using the same. In one embodiment, the present invention provides a composition for a weld filler comprising nickel, iron, and chromium, which collectively comprise at least 50% by weight of the weld filler; niobium, carbon, manganese, molybdenum, and silicon, which collectively comprise no more than 50% by weight of the weld filler, and a niobium to carbon ratio of approximately 20 or less.

Weld filler for welding dissimilar alloy steels and method of using same

This invention relates to a method and apparatus for controlling the composition of a weld. More particularly it relates to welding using an electric circuit, thereby creating a weld puddle, and adding at least one filler that is electrically independent from the electric circuit to the weld puddle at a controllable rate to obtain a target weld composition. The filler can be added to the extent limited by practical weld puddle geometry and, thus, the method and apparatus also facilitate increased weld deposition rates.

Controlled composition welding method

A method of repairing a metallic component, such as a superalloy turbine blade or turbine nozzle, includes the step of preparing the component by stripping the protective coatings from the component. The component is then pre-conditioned for welding by a first hot isostatic process. Once the conditioning sequence is complete, the component is welded using any of a number of welding techniques and by adding weld fillers to the weld area. After the welding step, the component is sealed by a second hot isostatic process treatment performed at conditions similar to the first hot isostatic process. The component is finally prepared for re-entry into service.

Method and apparatus for repairing superalloy components

A method of repairing a metallic member, such as a superalloy turbine blade, includes the step of preparing the blade by stripping the protective coatings from the blade. The blade is then pre-conditioned for welding by a first hot isostatic process. Once the blade conditioning sequence is complete, the blade is welded using a laser welding technique and by adding weld fillers to the weld area. After the welding step, the blade is sealed by a second hot isostatic process treatment performed at conditions similar to the first hot isostatic process. The blade is finally prepared for re-entry into service.

Apparatus and method of repairing turbine blades

A method for repairing a shrink-fitted turbine disc without removing the disc from the shaft. The method is composed of two basic steps: (1) depositing one or more weld layers in a vicinity of a defective region of the disc using a temperbead welding process and (2) heat treating the disc using an induction heating process. In a first embodiment of the method, the heat treating step includes heating a heat-affected zone of the disc in a vicinity of the one or more weld layers to a temperature T.sub.h, heating a rim region of the disc to a temperature T.sub.r and heating a bore region of the disc to a temperature T.sub.b, where T.sub.h, T.sub.r &gt;T.sub.b. In a second embodiment of the method, the heat treating step includes heating a region of the disc in a vicinity of the one or more weld layers using the induction heating process and concurrently cooling a bore region of the disc. In a third embodiment of the method, the heat treating step includes heating at least a portion of the disc using the induction heating process and concurrently heating the shaft to maintain a predetermined temperature differential between the bore region of the disc and the shaft. In a fourth embodiment of the method, the heat treating step includes heating at least a portion of the disc using the induction heating process and concurrently heating the shaft to maintain a uniform temperature between the bore region of the disc and the shaft.

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Saratoga, CA, United States of America

Ramaswamy Viswanathan