Abstract: A hot-wire nozzle for feeding pre-heated filler material into a welding groove. The nozzle has a contact tube made of electrically conductive material surrounded by a thin structural outer sheath. The outer sheath is electrically insulated from the contact tube by means of layers of electrically insulating material sandwiched between the contact tube and the outer sheath. The contact tube is configured to feed two or more filler wires simultaneously.

Abstract: A submersible thermal processing apparatus including a welding torch having an electrode, a housing and an inlet for pressurized gas; a shielding gas nozzle mounted to the torch housing and surrounding at least a portion of the electrode; and a fluid-permeable baffle made of elastic, heat-resistant spring material arranged in a closed loop and mounted to a distal end of the shielding gas nozzle. This water exclusion device acts as a movable, flexible, gas-flow permeable baffle, and is used in contact with and/or close proximity to the workpiece surface. One preferred shape of the cross section of the device is elliptical, with the coils of the spring inclined at an angle to the general path around the device so as to allow the overall helix shape to be readily compressed and released through larger deflections than the conventional design of baffle.

Abstract: A filler material guide nozzle assembly for feeding fusible filler metal wire or other metal forms into reduced-width, high-aspect-ratio (ratio of depth to width) metallic joints with control and stability of the filler metal position as it enters the molten pool area. The filler material guide nozzle assembly is designed with a thin but stiff non-circular cross-sectional shape, with its width dimension significantly greater than its thickness dimension, and can be utilized in very reduced-width welded or otherwise fused joints to provide the accuracy and stability required for reliable filler material addition. During use with welding, brazing and similar processes, the outlet end of the nozzle is located within the joint near the bottom, close to the area to be fused. The width dimension of the nozzle apparatus is oriented parallel to the depth of the weld joint, and the thickness dimension is oriented perpendicular to the depth of the joint.

Abstract: A durable coating process which provides improved adhesive bond strength between the coating and its substrate. This process utilizes spray parameters which generate a unique plasma coating that can be applied through a liquid environment between the spray gun nozzle and the substrate to provide combined ion cleaning, etching and activation of the surface to be coated. The improved surface conditioning allows the creation of an exceptionally strong metallurgical bond at the interface between the splattered droplets of the coating material and the substrate. The improved plasma coating process utilizes a relatively short nozzle-to-work surface distance and is therefore suitable for use directly in a liquid such as water in order to keep the substrate from overheating, which may be more likely to occur if the coating were applied in a gas or vacuum environment.

Abstract: A method of arc voltage sensing and electrode position control during mechanized electric arc welding. This welding method utilizes a lower power mode of the arc which has an improved voltage sensing geometry, and allows welds to be reliably made between components having small weld joint widths. The arc voltage is sensed only during the lower power mode. The sensing step is performed at a sensing time which is delayed relative to the start of said low power period, the duration of the delay being sufficient to allow the weld pool produced during the high power period to partially solidify. This method improves the voltage stability and arc position of the welding process, preventing the problem of the arc "climbing" the side walls of the weld groove. During the low-power arc voltage sensing mode, the arc is narrower and therefore more focused on the preferred bead center sensing position of a weld pass rather than spread out onto the adjacent side walls.

Abstract: A multiple-filler-material guide nozzle assembly for feeding multiple fusible filler metal wire or other metal forms into reduced-width, high-aspect-ratio (ratio of depth to width) metallic joints with control and stability of the filler metal position as it enters the molten pool area. The multiple filler materials are fed concurrently at the same or different feed rates. To control the aiming consistency for each of the multiple fillers even with substantial amounts of "cast" in the filler shape (after being unwound from a spool), the nozzle holes can be curved to match the curvature of the "cast" filler wire. This forces the curved filler wire to consistently follow the predetermined orientation of the curved shape of the nozzle. The multiple nozzles can be used to compensate for weld dilution effects by alloying to generate more favorable uniform, gradient or stepped compositions in joints or cladding.

Abstract: A process for providing a significant improvement in the detrimental tensile residual stress condition on the root side of welds, especially on the inside wall of piping welds. The method uses a high welding torch travel speed (>10 inches/min), especially on the last one or two cap passes. The process relies on the limited thermal heat sink capability of the pipe wall and nearly completed weld joint itself to generate a significant through-wall temperature gradient, and therefore a sufficient through-wall stress gradient during the welding. This stress gradient results in metal plasticity and permanent strains, and therefore a reduction in the magnitude of the final residual stress or, preferably as conditions allow, a reversal in the direction of the stresses from tensile to compressive. The method can be used as a welding process or as a heat treatment. In the case of heat treatment, the far surface of the weld joint is heated without fusion of the material making up the far surface.

Abstract: A welding process and an apparatus used therein for providing a significant improvement in the detrimental tensile residual stress condition on the root side of welds, especially on the inside wall of piping welds. The method combines an extremely thin weld joint design with a non-circular cylindrical, thin welding electrode having an elongated cross-sectional shape. During welding, the elongated dimension is aligned parallel with the length of the weld joint. This combination enables joining of piping and other residual stress-sensitive components with both the initial weld joint preparation and the completed weld having a uniquely thin width and with a high aspect ratio of depth to width. Use of this high-aspect-ratio weld joint process substantially mitigates welding-induced residual stresses, without the normally required internal water cooling.

Abstract: A welding electrode for providing a significant improvement in the detrimental tensile residual stress condition on the root side of welds, especially on the inside wall of piping welds. The electrode has a tungsten alloy blade. The blade is made from sheets of tungsten alloy by cutting or stamping. The preferred shape of the blade is an isosceles triangle. The base of the flat triangular blade is secured in a slot formed in an electrode holder. The electrode holder is preferably T-shaped, with the shank of the holder being connected to a conventional welding torch. The holder is made of electrically conductive material, whereby the blade is coupled to the torch for producing an electric arc at the blade tip for welding. The blade is optionally covered with a ceramic coating to prevent arcing to the side walls of the groove formed between the parts being welded. A further option is to incorporate insulating stand-offs which protrude from both flat sides of the electrode blade.