Abstract: System and method for engraving an image on a workpiece, such as a nuclear steam generator tubesheet. The system includes a laser assembly for generating a pulsed laser beam to engrave the image adjacent a target position on the workpiece. A positioning mechanism is connected to the laser assembly for positioning the laser assembly with reference to the target position. A controller is electrically connected to the positioning mechanism for controlling the positioning mechanism in order to controllably position the laser assembly at the target position and for verifying the image engraved at the target position. A computer is electrically connected to the controller for receiving the verified image. The computer is also electrically connected to the laser assembly for operating the laser assembly so that the laser beam emitted thereby engraves the image on the tubesheet at the target position.

Abstract: An end face of a work-piece having a circular opening is welded upon by apparatus which includes a stationary post mounted by a mounting assembly to the work-piece with its longitudinal axis coincident with the axis of the opening. A rotating assembly includes a sleeve rotatably mounted on the post and supporting a slide extending laterally from the sleeve. A weld head is supported by a carriage which reciprocates along the slide and has a weld electrode extending toward the end face of the work-piece. Rotation of the sleeve and movement of the carriage are coordinated so that a spiral weld pattern with overlapping turns is laid down on the end face. Cooling water and cover gas, as well as electrical power and control signals for GTAW-HW welding are delivered to the rotating assembly through rotating connections on the post.

Abstract: An improved tungsten inert gas-shielded non-consumable composite welding electrode having a solid tungsten rod center (12) and a concentric outer sleeve (14) substantially lower in electrical resistivity than the tungsten rod, bonded adhesively and cohesively to the tungsten by flame spraying so that the surface irregularities of the mating surface areas of the tungsten and outer sleeve mechanically interlock. The improvement is provided by coating the outer sleeve onto the tungsten center and adhesively and cohesively bonding the interface of the surface area of contact to maintain a minimum resistance electric coupling at welding operating temperatures.

Abstract: Apparatus for tracking a welding electrode (22) within a weld groove (12). As the welding arc struck between the electrode (22) and the workpiece (16) is oscillated laterally (14) within the groove means (28 and 30) are provided for supplying an indication of both the voltage drop between the electrode and the side wall of the groove as the arc approaches the side wall, and the width of the excursion of the arc from the center of oscillation to the point where the voltage is measured. The center of oscillation is then adjusted as a function of the measured width and voltage.

Abstract: A welding torch is rotatably mounted in a carriage. The carriage and welding torch are driven by motors and driveshafts mounted on a base to provide a light carriage which can be rapidly accelerated as the torch moves from tube to tube when forming a continuous weld encompassing the juncture of a plurality of tubes.

Abstract: A gas tungsten arc welding torch having an elongated gas nozzle (18) with an oblong cross section designed for deep groove, narrow gap welding. The nozzle is rotatably coupled to and communicates with a gas port within the main torch body (16) and defines a gas passage along the length of the welding electrode (10), which extends through the longitudinal axis of the nozzle. The nozzle (18) includes a detachable end section (42) which captures and supports a replaceable gas lens (30) disposed within the gas passage of the nozzle within 7/8 to 1 inch from the nozzle orifice (40), and traverse to the direction of gas flow. The electrode (10) is formed from a solid tungsten rod center (12) and a concentric outer sleeve (14) substantially lower in electrical resistivity than the tungsten rod, which is adhesively and cohesively bonded to the tungsten. The outer sleeve extends from the point of electrical connection (32) within the main torch body (16) to a point on the tungsten electrode downstream of the gas lens.

Abstract: A method of applying a gas shielded tungsten arc welding process in a deep, narrow groove joint wherein the shield gas is directed to the weld puddle through an elongated gas nozzle 14 which surrounds a substantial length of the welding electrode and is sized to extend into the groove. The improvement including incrementally increasing the width (20) of the nozzle to correspond to increases in the width of the groove at preselected increases in the width of the groove as the nozzle is withdrawn from the groove during successive weld passes. The preselected elevations and nozzle widths are chosen so that the desired gas shield area does not substantially exceed 1.25 times the nozzle width.

Abstract: A method and apparatus for preheating filler material to a temperature approaching its melting point prior to deposit within a weld zone. The weld zone and deposited filler material are then heated sufficiently to form an integral weldment. The power imparted to preheat the filler material is automatically, programmably, controlled as a predetermined function of the filler material deposition rate to obtain smooth melting of the filler material within the weld zone at any given filler material feed speed.In an application to welding an extended seam along a workpiece wherein the weld zone is moved along the seam, the power employed to heat the weld zone and the filler material feed speed are additionally controlled as a function of the speed of movement of the weld zone along the seam.