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: 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.