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A process for closing an opening in a surface of a component, and components formed thereby. The process entails forming a channel in the component surface so that the channel at least partially surrounds an opening at the component surface. An alloy is then deposited in the channel to form a crack-

A process for closing an opening in a surface of a component, and components formed thereby. The process entails forming a channel in the component surface so that the channel at least partially surrounds an opening at the component surface. An alloy is then deposited in the channel to form a crack-free deposit in the channel. A step is then machined that intersects the opening and is at least partially formed in the deposit. The step defines a recess that is at least partially surrounded by a peripheral portion of the deposit and has a surface recessed into the component surface. A cap is placed in the recess and welded to the peripheral portion of the deposit to define a weld joint that completely closes the opening. The surface of the weld joint is then machined to form a machined surface that is substantially flush with the component surface.

대표청구항 ▼

1. A process of closing an opening at a surface of a component formed of a first alloy, the process comprising: forming a channel in the surface of the component, the channel at least partially surrounding the opening at the surface of the component;depositing a second alloy in the channel to form a

1. A process of closing an opening at a surface of a component formed of a first alloy, the process comprising: forming a channel in the surface of the component, the channel at least partially surrounding the opening at the surface of the component;depositing a second alloy in the channel to form a crack-free deposit in the channel so that the deposit at least partially surrounds the opening, the second alloy having better weldability than the first alloy;machining a step that intersects the opening and a surface of the deposit and is at least partially formed in the deposit by removing a portion of the deposit within the channel, the step defining a recess that is at least partially surrounded by a peripheral portion of the deposit and has a machined recessed surface that is at least partially defined by the deposit and recessed into the surface of the component;placing a cap in the recess so as to cover the opening at the surface of the component;welding the cap to the peripheral portion of the deposit to define a weld joint that completely closes the opening, the weld joint having a surface formed in part by surfaces of the cap, a weldment surrounding the cap, and the peripheral portion of the deposit; and thenmachining the surface of the weld joint to form a machined surface that is at the surface of the component and defined by portions of the cap, the weldment, and the peripheral portion of the deposit. 2. The process according to claim 1, wherein the channel is formed to completely surround the opening. 3. The process according to claim 1, wherein the channel is formed to define a lip in the surface of the component that separates the channel from the opening in the surface of the component, and the machining of the step to define the recess removes some but not all of the lip. 4. The process according to claim 3, wherein the channel is formed to completely surround the opening, and the lip entirely separates the channel from the opening in the surface of the component. 5. The process according to claim 1, wherein the second alloy is deposited so that the deposit completely surrounds the opening. 6. The process according to claim 1, wherein the step is machined to completely surround the opening and the entire perimeter of the opening is intersected by the step. 7. The process according to claim 1, wherein the step is machined so that the peripheral portion of the deposit completely surrounds the recess. 8. The process according to claim 1, wherein the cap is welded only to the peripheral portion of the deposit. 9. The process according to claim 1, wherein the step is machined so that the surface of the recess is parallel to the surface of the component. 10. The process according to claim 1, wherein the first alloy is a nickel-base superalloy containing a combined amount of aluminum and titanium of greater than five weight percent. 11. The process according to claim 1, wherein the second alloy is a nickel-base superalloy containing a combined amount of aluminum and titanium of less than five weight percent. 12. The process of claim 1, wherein the component is a cast hot gas path component of a gas turbine. 13. A process of filling an opening in a hot gas path component of a gas turbine, the component being cast from a first nickel-base superalloy and the opening being formed by a rod that supported a core within the component during casting of the component, the process comprising: forming a channel in a surface of the component, the channel completely surrounding the opening at the surface of the component;depositing a second nickel-base superalloy in the channel to form a crack-free deposit in the channel that completely surrounds the opening at the surface of the component, the second nickel-base superalloy having better weldability than the first nickel-base superalloy as a result of having a lower Ti+Al content than the first nickel-base superalloy;machining a step that is at least partially formed in the deposit by removing a portion of the deposit within the channel, wherein the step intersects a surface of the deposit, is completely surrounded by a peripheral portion of the deposit, and completely surrounds and intersects the entire perimeter of the opening, the step defining a recess that is completely surrounded by the peripheral portion of the deposit and has a machined recessed surface that is at least partially defined by the deposit and recessed into the surface of the component;placing a cap in the recess so as to cover the opening at the surface of the component;welding the cap to only the peripheral portion of the deposit to define a weld joint that completely closes the opening, the weld joint having a surface at which a surface of the cap is surrounded by a surface of a weldment that is surrounded by a surface of the peripheral portion of the deposit; and then machining the weld joint to form a machined surface that is flush with the surface of the component and defined by portions of the cap, the weldment, and the peripheral portion of the deposit. 14. The process according to claim 13, wherein the channel is formed to define a lip in the surface of the component that completely separates the channel from the opening in the surface of the component, and the machining of the step to define the recess removes some but not all of the lip. 15. The process according to claim 13, wherein the second nickel-base superalloy is deposited by a laser powder deposition process. 16. The process according to claim 13, wherein the first nickel-base superalloy contains a combined amount of aluminum and titanium of greater than five weight percent, and the second nickel-base superalloy contains a combined amount of aluminum and titanium of less than five weight percent. 17. The process according to claim 16, wherein the first nickel-base superalloy has a nominal composition, in weight percent, of about 14.0% Cr, about 9.5% Co, about 3.0% Al, about 4.9% Ti, about 1.5% Mo, about 3.8% W, about 2.8% Ta, about 0.010% C, the balance nickel and incidental impurities. 18. The process according to claim 16, wherein the first nickel-base superalloy has a nominal composition of, by weight, about 7.5% Co, about 7.0% Cr, about 6.5% Ta, about 6.2% Al, about 5.0% W, about 3.0% Re, about 1.5% Mo, about 0.15% Hf, about 0.05% C, about 0.004% B, about 0.01% Y, the balance nickel and incidental impurities. 19. The process according to claim 13, wherein the second nickel-base superalloy consists essentially of, by weight, of about 22.2-22.8% chromium, about 18.5-19.5% cobalt, about 2.2-2.4% titanium, about 1.1-1.3% aluminum, about 3.2-3.8% titanium+aluminum, about 1.8-2.2% tungsten, about 0.7-0.9% niobium, about 0.9-1.1% tantalum, about 0.005-0.020% zirconium, about 0.005-0.015% boron, about 0.8-0.12% carbon, with the balance being nickel and incidental impurities. 20. The process of claim 13, wherein the component is chosen from the group consisting of turbine buckets and turbine nozzles.