General Electric Company

Oliver Crispin Robotics Limited

Eric Scott Huron

David Paul Mourer

Edward Lee Raymond

Michael F Henry

Charles P Blankenship, Jr

Mark Gilbert Benz

Douglas Gerard Konitzer

Kenneth Rees Bain

Allen J Paxson

Robert D Kissinger

Andrew Crispin Graham

Swami Ganesh

Keith Anthony Lauria

William Clarke Brooks

John Matthew Powers

Evan Jarrett Dolley

Shesh Krishna Srivatsa

Daniel Edward Wines

Jon Raymond Groh

Erica Elizabeth Sampson

Paul L Reynolds

John J Schirra

Enrique E Montero

Duk Y Yoon

Glenn Charles Culbertson

Ronald Gene Tolbert

Aldo Enrique Murut

Daniel David Noe

Brian Francis Mickle

John Michael Hyzak

Jack E Howson

Vijayaraghava Venkata Nalladega

Renee M Rohling

Robert Donald Kissinger

Brian James Girvin

Ian Thomas Goodall

David Edward Trider

Zeynep Bolukoglu

Doga Ulutas

Katherine Quinn

Aida Amroussia

Tugba Aydin

Nikole Joy Kucza

Timothy Paul Gabb

John Joseph Schirra

Paul Leray Reynolds

Daniel Gustov Backman

Methods of protecting a metallic substrate from corrosion include introducing an aqueous or powder-form composition including at least one corrosion inhibitor into a crevice that traverses one or more layers covering the metallic substrate to deliver the composition via the crevice into contact with a surface of the metallic substrate. The corrosion inhibitors present in the composition bond to the surface of the metallic substrate, resulting in formation of a film on the surface of the metallic substrate. This film protects the surface of the metallic substrate against corrosion.

Systems and methods of protecting metallic engine components from corrosion

Methods for cleaning a superalloy substrate having engine deposits on its surface are provided. The method may include applying a permanganate solution onto the surface of the superalloy substrate, and applying a ferric chloride based cleaning composition onto the surface of the superalloy substrate. The ferric chloride based cleaning composition includes ferric chloride and at least one of nitric acid and phosphoric acid, such as within a solvent system (e.g., an aqueous solution including water).

Cleaning compositions and methods for removing oxides from superalloy substrates

A process of fabricating a rotating component and a rotating component formed thereby. The rotating component has a rotational axis, at least one rim member, at least one disk member, and at least one airfoil member. The rim and disk members are welded together to define a first solid-state weld joint lying in a first plane that is not parallel to the rotational axis of the rotating component. The airfoil member is welded to the rim member to define a second solid-state weld joint lying in a second plane that is not parallel to the rotational axis of the rotating component. The rim member is located in a radially outward direction from the disk member, and the airfoil member is located in a radially outward direction from the rim member.

Welding process and component formed thereby

A process of fabricating a rotating component and components formed thereby. The process includes fabricating preforms corresponding to portions of the component. Each preform has an interface surface at which the preforms can be joined to locate a first of the portions in a radially outward direction from a second of the portions. The preforms are then inertia welded together to form a profile having a solid-state weld joint containing a finer-grained material than other portions of the profile. The profile is then forged with dies to produce a forging. At least one of the dies has a recess into which the finer-grained material from the weld joint is expelled during forging to purge a joint region of the forging between the forging portions of the finer-grained material. The joint region contains grains distorted in an axial direction of the forging.

Welding process and component produced therefrom

A method of forming a component from a gamma-prime precipitation-strengthened nickel-base superalloy so that, following a supersolvus heat treatment the component characterized by a uniformly-sized grain microstructure. The method includes forming a billet having a sufficiently fine grain size to achieve superplasticity of the superalloy during a subsequent working step. The billet is then worked at a temperature below the gamma-prime solvus temperature of the superalloy so as to form a worked article, wherein the billet is worked so as to maintain strain rates above a lower strain rate limit to control average grain size and below an upper strain rate limit to avoid critical grain growth. Thereafter, the worked article is heat treated at a temperature above the gamma-prime solvus temperature of the superalloy for a duration sufficient to uniformly coarsen the grains of the worked article, after which the worked article is cooled at a rate sufficient to reprecipitate gamma-prime within the worked article.

Method of controlling final grain size in supersolvus heat treated nickel-base superalloys and articles formed thereby

A superalloy has a composition of, in weight percent, from about 16.0 percent to about 22.4 percent cobalt, from about 6.6 percent to about 14.3 percent chromium, from about 1.4 percent to about 3.5 percent tantalum, from about 1.9 percent to about 4.0 percent tungsten, from about 1.9 percent to about 3.9 percent molybdenum, from about 0.03 percent to about 0.10 percent zirconium, from about 0.9 percent to about 3.0 percent niobium, from about 2.4 percent to about 4.6 percent titanium, from about 2.6 percent to about 4.8 percent aluminum, from 0 to about 2.5 percent rhenium, from about 0.02 percent to about 0.10 percent carbon, from about 0.02 percent to about 0.10 percent boron, balance nickel and minor amounts of impurities. The superalloy is advantageously utilized in aircraft gas turbine disks.

Superalloy optimized for high-temperature performance in high-pressure turbine disks

A .gamma.' precipitation strengthened nickel-base superalloy provided in powder metal or cast and wrought form and alloyed to minimize nucleation tendencies and control grain growth. The superalloy includes a fine dispersion of a second phase in sufficient amounts to prevent critical grain growth in the superalloy when the superalloy is subjected to temperatures above its .gamma.' solvus temperature. The superalloy preferably contains at least about 0.030 weight percent carbon or about 27 to about 2000 ppm yttrium in order to produce a volume fraction of the second phase which is sufficient to cover a minimum of about 10 percent of the grain boundary area. The fine dispersion of the second phase restricts the grain boundary motion of the alloy during supersolvus heat treatment, thereby preventing random grain growth during supersolvus heat treatment and yielding a microstructure whose grain size is uniform, for example, having a grain size range of about 2 to about 3 ASTM units and being substantially free of random grain growth in excess of about 2 ASTM units coarser than the desired grain size range.

Nickel-base superalloy having improved resistance to abnormal grain

A method for forming nickel base superalloy articles of manufacture by a combination of hot die forging, isothermal forging and heat treatment below and above the solvus.

Grain size control in nickel base superalloys

A method of high retained strain forging is described for Ni-base superalloys, particularly those which comprise a mixture of .gamma. and .gamma.' phases, and most particularly those which contain at least about 30 percent by volume of .gamma.'. The method utilizes an extended subsolvus anneal to recrystallize essentially all of the superalloy and form a uniform, free grain size. Such alloys may also be given a supersolvus anneal to coarsen the grain size and redistribute the .gamma.'. The method permits the manufacture of forged articles having a fine grain size in the range of about ASTM 5-12 (5-60 .mu.m).

Method for controlling grain size in Ni-base superalloys

A method is provided for obtaining uniform grain growth within .gamma.' precipitation strengthened nickel-base superalloys provided in powder metal or cast and wrought form. The method includes alloying the nickel-base superalloy to contain a minimum calculated amount of carbon which, when finely dispersed within the alloy using suitable processing methods, yields a sufficient amount of carbide phase which restricts the grain boundary motion of the alloy during supersolvus heat treatment. When appropriately processed, the grains are not permitted to grow randomly during supersolvus heat treatment, making possible a microstructure whose grain size is uniform, having a grain size range of about 2 to about 3 ASTM units and being substantially free of random grain growth in excess of about 2 ASTM units coarser than the desired grain size range.

Method for forming a nickel-base superalloy having improved resistance

A method is provided for reducing the tendency for thermally induced porosity within a .gamma.' precipitation strengthened nickel-base superalloy which has been processed to obtain a uniform and coarse grain microstructure. This method is particularly useful for forming components such as gas turbine compressor and turbine disk assemblies in which optimal mechanical properties, such as low cycle fatigue and creep resistance, are necessary for operating at elevated temperatures within a gas turbine engine. The method generally entails alloying a .gamma.' precipitation strengthened nickel-base superalloy to have a boron content of not more than about 0.02 weight percent, and then forming a billet by melting an ingot of the superalloy in an argon gas atmosphere and atomizing the molten superalloy using argon gas. The above atomizing technique encompasses both powder metallurgy and spray forming processes.

Method for reducing thermally induced porosity in a polycrystalline

A method is provided for obtaining a uniform grain size on the order of about ASTM 5 or coarser in at least a portion of an article formed from a .gamma.' precipitation strengthened nickel-base superalloy. The method comprises forming an article by: providing a billet, preheating the billet above 2000.degree. F. for at least 0.5 hours, working at least a portion to near-net shape at working conditions including a first strain rate of less than about 0.01 per second and at a subsolvus temperature at or near the recrystallization temperature, supersolvus heating to form a grain size in the portion of at least 5 ASTM, and cooling to reprecipitate .gamma.' within the article. The method can be utilized to form a .gamma.' precipitation strengthened nickel-base superalloy article whose grain size varies uniformly between portions thereof, so as to yield a desirable microstructure and property gradient in the article in accordance with the in-service temperature and stress-state gradient experienced by the article. The method is particularly useful for the making of relatively large components such as turbine disks used in gas turbine engines, which are subjected to stress and temperature conditions that vary radially from the center of the disk to its outer rim.

Thermomechanical processing method for achieving coarse grains in a

A method is provided for obtaining uniform grain growth within .gamma.' precipitation strengthened nickel-base superalloys. The method includes forming a billet having a very fine grain size in order to achieve optimum superplasticity of the superalloy during forging. The article is then heated to a pre-working hold temperature in a manner which prevents coarsening of the microstructure and a loss of superplasticity. The article is then worked, such as by forging, at a temperature below the .gamma.' solvus temperature of the alloy, so as to maintain local strain rates within the article below a critical strain rate for random grain growth, and so as to maintain the strain rate gradient throughout the article below a critical upper limit. After working, the article is subjected to annealing at a temperature which is less than the .gamma.' solvus temperature of the alloy, and for a duration which is sufficient to remove accumulated metallurgical strain in the article. A supersolvus heat treatment is then performed by further heating the article to a temperature above the .GAMMA.' solvus temperature of the superalloy for a duration sufficient to uniformly coarsen the grains of the article.

Method for minimizing nonuniform nucleation and supersolvus grain growth

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West Chester, OH, United States of America

Eric Scott Huron