Abstract: A method of eliminating dissimilar metal welds has been disclosed. The method includes the steps of providing a first part having a first alloy composition; providing a second part having a second alloy composition different from the first part; connecting a containment structure to the first part; pouring a powder into the containment structure such that the powder is in contact with the first part; positioning a portion of the second part in the containment structure such that the second part compresses the powder between the first and second parts; and performing hot isostatic pressing (HIP) to consolidate the powder and join the first and second parts together.

Abstract: A method of eliminating dissimilar metal welds has been disclosed. The method includes the steps of providing a first part having a first alloy composition; providing a second part having a second alloy composition different from the first part; connecting a containment structure to the first part; pouring a powder into the containment structure such that the powder is in contact with the first part; positioning a portion of the second part in the containment structure such that the second part compresses the powder between the first and second parts; and performing hot isostatic pressing (HIP) to consolidate the powder and join the first and second parts together.

Abstract: A method of eliminating dissimilar metal welds has been disclosed. The method includes the steps of providing a first part having a first alloy composition; providing a second part having a second alloy composition different from the first part; connecting a containment structure to the first part; pouring a powder into the containment structure such that the powder is in contact with the first part; positioning a portion of the second part in the containment structure such that the second part compresses the powder between the first and second parts; and performing hot isostatic pressing (HIP) to consolidate the powder and join the first and second parts together.

Abstract: A strain-hardenable stainless steel alloy includes hard secondary phases dispersed in an austenitic primary phase, the alloy including 0.3-0.6% nitrogen by weight.

Abstract: A strain-hardenable stainless steel alloy includes hard secondary phases dispersed in an austenitic primary phase, the alloy including 0.3-0.6% nitrogen by weight.

Abstract: A method of eliminating dissimilar metal welds has been disclosed. The method includes the steps of providing a first part having a first alloy composition; providing a second part having a second alloy composition different from the first part; connecting a containment structure to the first part; pouring a powder into the containment structure such that the powder is in contact with the first part; positioning a portion of the second part in the containment structure such that the second part compresses the powder between the first and second parts; and performing hot isostatic pressing (HIP) to consolidate the powder and join the first and second parts together.

Abstract: A strain-hardenable stainless steel alloy includes hard secondary phases dispersed in an austenitic primary phase, the alloy including 0.3-0.6% nitrogen by weight.

Abstract: A method for the inspection and repair of a tube includes electrical discharge machining an access hole into the tube, optionally at or near the uppermost location on the tube, near the upper header; performing inspection of the tube, optionally using a visual or an eddy current inspection technique; providing an inner diameter flush-mounted plug insert which has been machined for re-inserting into the access hole; and attaching the plug insert to the tube.

Abstract: 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.

Abstract: A method for repairing a heat recovery steam generator (HSRG) header to tube attachment damage, includes providing an access window in the header opposite the damaged header to tube attachment location; removing the header to tube attachment damage; inserting a tapered stub tube into a header penetration centered axially immediately over the tube; effecting a profile weld between the header and the tapered stub tube at the header penetration from the inside surface of the header; welding the tapered stub tube to the existing tube through the header inside diameter; welding shut the access window; and completing a post weld heat treatment of all the welds.

Abstract: 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.

Abstract: A method for repairing a heat recovery steam generator (HSRG) header to tube attachment damage, includes providing an access window in the header opposite the damaged header to tube attachment location; removing the header to tube attachment damage; inserting a tapered stub tube into a header penetration centered axially immediately over the tube; effecting a profile weld between the header and the tapered stub tube at the header penetration from the inside surface of the header; welding the tapered stub tube to the existing tube through the header inside diameter; welding shut the access window; and completing a post weld heat treatment of all the welds.

Abstract: Accordingly, the present invention provides a method for joining metallic members, which can be used to join component sub-assemblies. Further, the present invention provides a method for repairing a component by replacing a damaged portion and re-inserting a replacement section. In general, the present invention provides in one embodiment a method for joining metallic members comprising: preparing a surface of a first metallic member, thereby providing an oxide-free surface; preparing a surface of a second metallic member, thereby providing an oxide-free surface; applying pressure to the first and second metallic members, thereby forcing the surface of the first metallic member and the surface of the second metallic member together and forming a joint area; sealing an outer edge of the joint area; and subjecting the members to a hot isostatic process operation.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A method, an apparatus (150), and a prefabricated replacement tube (108) are provided for repairing a defect (112) in a tube (102), such as in a waterwall (100). In the method, a replacement tube (108) is prefabricated having a wall (116), a central opening (114) extending through a portion thereof, and a predetermined length. A length of the tube (102), including the defect (112), equal to the predetermined length is removed. The replacement tube (108) is positioned between stubs (126, 128) of the tube (102), and a rotatable torch (152) of an automated welding apparatus (150) inserted through the opening (114) to align with a joint between an end (118, 120) of the replacement tube and a stub (126, 128). The torch (152) is rotated to join it to the stub (126, 128) along the entire joint. The torch (152) is then removed, turned 180 degrees, and reinserted to weld the remaining joint.

Abstract: A method, a apparatus (150) and a prefabricated replacement tube (108) are provided for repairing a defect (112) in a tube (102), such as in a waterwall (100). In the method, a replacement tube (108) is prefabricated having a wall (116), a central opening (114) extending through a portion thereof and a predetermined length. A length of the tube (102), including the defect (112), equal to the predetermined length is removed. The replacement tube (108) is positioned between stubs (126, 128) of the tube (102), and a rotatable torch (152) of an automated welding apparatus (150) inserted through the opening (114) to align with a joint between an end (118, 112) of the replacement tube and a stub (126, 128). The torch (152) is rotated to join it to the stub (126, 128) along the entire joint. The torch (152) is then removed, turned 180 degrees, and reinserted to weld the remaining joint.

Abstract: 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.