Abstract: Ni base superalloys containing relatively large amounts of Al and/or Ti are known to be difficult to weld satisfactorily. As the Al and Ti content of the superalloy is increased to improve the strength, the weldability of the component is drastically reduced. It is concluded herein that reducing the ?? phase improves weldability. A stepwise, controlled heating and cooling process is described to be used in cooperation with a welding process to reduce the ?? present and thereby improve weldability.

Abstract: Ni base superalloys containing relatively large amounts of Al and/or Ti are known to be difficult to weld satisfactorily. As the Al and Ti content of the superalloy is increased to improve the strength, the weldability of the component is drastically reduced. It is concluded herein that reducing the ?? phase improves weldability. A stepwise, controlled heating and cooling process is described to be used in cooperation with a welding process to reduce the ?? present and thereby improve weldability.

Abstract: A method of welding a gas turbine engine substrate composed of a gamma prime precipitation strengthened nickel based superalloy, including the steps of: applying weld beads on the substrate to form a continuous layer the thickness of the weld beads; using a filler material made of a first material exhibiting comparable strength and ductility as the substrate, and a second material exhibiting greater ductility than the substrate; and creating crack propagation mitigating regions within the continuous layer by increasing the percentage of the second material in the crack propagation mitigating regions over the percentage of the second material in the remainder of the continuous layer.

Abstract: A method for welding superalloy components at ambient temperature conditions while reducing the propensity of the superalloy material to crack as a result of the weld. A root pass region of the weld is formed using a filler material that exhibits ductility that is higher than that of the base superalloy material. The ductile material mitigates stress in the root region, thereby preventing the formation of cracks. A remaining portion of the weld is formed using a filler material that essentially matches the base superalloy material. The method may utilize a pre-weld heat treatment to grow a gamma prime precipitate phase in the superalloy material, a chill fixture to remove heat during welding, a relief cut to reduce stress in the root region, and a conventional post-weld heat treatment.

Abstract: The repair of cracks according to the state of the art comprises the fact that defects located on the inside must be worked outward in order to be able to be welded closed. The method according to the invention proposes not to work out cracks located on the inside, but to melt the crack located on the inside utilizing a flux agent.

Abstract: A method of applying a weld using a gas tungsten arc welding procedure. A filler element is provided to a welding location. The filler element includes a first material used during formation of a weld, and a second material that is capable of producing a slag upon melting thereof. A welding arc provides heat that melts portions of first and second components and the filler element proximate to the welding location to form a weld pool. The second material melts and forms a slag, which flows to an outer surface of the weld pool and shields the weld pool from exposure to reactive elements in the atmosphere. Upon cooling of the weld pool, the weld pool solidifies to form a weld between the first component and the second component.

Abstract: A method of welding a gas turbine engine substrate composed of a gamma prime precipitation strengthened nickel based superalloy, including the steps of: applying weld beads on the substrate to form a continuous layer the thickness of the weld beads; using a filler material made of a first material exhibiting comparable strength and ductility as the substrate, and a second material exhibiting greater ductility than the substrate; and creating crack propagation mitigating regions within the continuous layer by increasing the percentage of the second material in the crack propagation mitigating regions over the percentage of the second material in the remainder of the continuous layer.

Abstract: The repair of cracks according to the state of the art comprises the fact that defects located on the inside must be worked outward in order to be able to be welded closed. The method according to the invention proposes not to work out cracks located on the inside, but to melt the crack located on the inside utilizing a flux agent.

Abstract: A method of stress relief for stainless steel combustion turbine components includes vibrating the components during welding at a subharmonic frequency. The proper frequency is selected to be below a harmonic frequency, and to produce an amplitude in the range of ¼ to ½ the amplitude produced by a harmonic frequency. The component to be repaired is vibrated during and after welding at this frequency.

Abstract: A method for welding superalloy components at ambient temperature conditions while reducing the propensity of the superalloy material to crack as a result of the weld. A root pass region of the weld is formed using a filler material that exhibits ductility that is higher than that of the base superalloy material. The ductile material mitigates stress in the root region, thereby preventing the formation of cracks. A remaining portion of the weld is formed using a filler material that essentially matches the base superalloy material. The method may utilize a pre-weld heat treatment to grow a gamma prime precipitate phase in the superalloy material, a chill fixture to remove heat during welding, a relief cut to reduce stress in the root region, and a conventional post-weld heat treatment.

Abstract: A method of stress relief for stainless steel combustion turbine components includes vibrating the components during welding at a subharmonic frequency. The proper frequency is selected to be below a harmonic frequency, and to produce an amplitude in the range of ¼ to ½ the amplitude produced by a harmonic frequency. The component to be repaired is vibrated during and after welding at this frequency.